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Poster Program


INTERNATIONAL POSTERS dealing with various aspects of PM and particulate materials technologies will be displayed daily starting on Monday morning. Authors will be available at their posters for discussion Monday (5:30–7:00 p.m.) during the PM Evening Alehouse. Manuscripts submitted from poster authors will be published in the conference proceedings.

“Outstanding Poster” and “Poster of Merit” awards will be given by the Poster Awards Committee for displays that best meet the established criteria. Award ribbons will be posted prior to the designated discussion period on Monday.

National Science Foundation, MPIF, and CPMT/Axel Masen student grant recipients' abstract titles are in burgundy.  Click the title to see when they will be presenting thier grant TNT.

Poster A: Materials               Poster B: Processing               Poster C: Properties

Poster A: Materials

092 - Effect of Time and Temperature on Microstructure Evolution of Infiltrant Liquid Phase Sintered MAR-M247
Coleton Parks

Liquid phase sintering has been widely utilized as one of the go-to alternatives to welding in the repair of turbine components in aerospace and power generation industries. In this study, the microstructural evolution of MAR-M247, using an infiltrating liquid filler alloy, BNi-9, was investigated. The parameters of interest were processing time and temperature. Through a combination of differential scanning calorimetry, and optical and electron microscopy, several insights were gleaned. (1) Once in the liquid state, the BNi-9 alloy readily infiltrated the porous MAR-M247 structure, via capillary action; (2) It was observed that significant densification was obtained prior to reaching isothermal sintering temperatures via particle rearrangement and solution-reprecipitation mechanisms; (3) As sintering time and temperature increased, a significant amount of coalescence and coarsening of MAR-M247 was observed due to enhanced mass transport and extended exposure to the liquid phase; (4) Intergranular BNi-9 was found to consist of binary eutectic constituents, γ-Ni and CrB, when sintered at 1,150°C and 1,180°C, while ternary eutectic constituents, γ-Ni, CrB, and Ni3B, were observed when sintered at 1,200°C. The implications on further research and industrial applicability are explored.

136 - Additive Manufacturing of an Alumina-Forming Ni-Base Alloy Haynes® 233™ - A Preliminary Assessment
Abdul Shaafi Shaikh, EOS Finland

An industrial success story in metal additive manufacturing has been the adoption of oxidation resistant high temperature materials in laser powder bed fusion. Ni-base alloys, primarily Hastelloy® X, have been used in laser powder bed fusion for serial production components in the energy and aerospace industries. With these industries moving to achieve lower emissions with higher temperatures and alternative fuels like hydrogen, there is a need to investigate materials that can serve for longer times in harsher environments. Alloys that form protective alumina scale have an inherent advantage over chromia scale formers due to the stability of alumina at higher temperatures. In this study an alumina forming Ni-base alloy called Haynes® 233™ was assessed for laser powder bed fusion processability. Its mechanical properties and early-stage oxidation performance were characterized at elevated temperatures and compared to Hastelloy® X. It was found that Haynes® 233™ is sensitive to defect formation during laser powder bed fusion processing, but also shows improved high temperature tensile, creep, and oxidation performance compared to Hastelloy® X.

902 - A Parametric Molecular Dynamics Study of Additive Nanomanufacturing:  Effects of Particle Size, Misorientation Angle, Material Type, and Temperature on Sintering Mechanisms
Dourna Jamshideasli, Auburn University

Laser-based additive nanomanufacturing technique is used to print flexible electronics with various substrates. This technique is based on nano scale metal generation, deposition, and sintering. The value of interfacial electrical resistance and the quality of the sintered materials depend on the final neck size, one of several geometric parameters that change during sintering of nano powders. Sintering is mediated by defects, and anticipating sintering requires tracking the involved mechanisms during neck size evolution. This study uses molecular dynamics simulations to investigate the effects of size, size ratio, misorientation angle, and temperature on the neck size of the sintered spherical silver and copper nano powders. For each case study, real-time trajectories of atoms that build the neck and spatiotemporal information of the defects through each nano powder were provided.

920 - Preparation of Re-W Powder Feedstocks Using Liquid Precursor Impregnation
Davis Conklin, University of Colorado Boulder

Rhenium-tungsten alloys are useful refractory metals due to their high-temperature mechanical strength, high density, and thermal conductivity. To produce a Re-W powder feedstock, pure metal or oxide powder precursors are typically blended or mechanically alloyed. Although this technique can be sufficient for conventional powder metallurgy, it is not suitable for additive manufacturing or other applications that require strict control over powder properties. This work applies a liquid precursor impregnation method to prepare Re-W powder feedstocks without altering the properties of the underlying W powder. The ability to produce various rhenium compositions on both fine 1-5 micron and spherical 15 micron W powders is demonstrated, and the powders are consolidated in a dilatometer to assess how this powder preparation influences densification behavior. The microstructure and compositional homogeneity of the consolidated alloys are investigated as well. Overall, this work evaluates a novel, facile power feedstock preparation method for refractory metal alloys.

928 - Investigation of Corrosion on PM Copper Steels Formed by Cold Sintering
Christian Bakaysa, Penn State Dubois

Cold sintering of copper steels is investigated to study the corrosion properties of phosphate coated iron.   A control group of samples have been compacted into transverse rupture bars (TRS bars) and pressed to 57,000 pounds.  The phosphate coated copper steel TRS bars were fabricated to the same conditions but were warm die compacted at 100 C. The application of surface modified particles in warm compaction has shown enhanced properties in various applications.  These properties of our TRS Bars will be studied by performing the following tests, salt spray per ASTM B117-19, immersion (ASTM B895-16), and humidity (ASTM D2247-15). For investigative purposes, the TRS Bars were compacted and stored in regular atmospheric conditions.  During this time, the coated bars did not exhibit rust as quickly as the control TRS group.

943 - Microstructural Control of a Multi-Phase PH Steel Printed with Laser Powder Bed Fusion
Brandon Fields, University of California, Irvine

The microstructure and properties have been observed to vary substantially in different locations of laser powder bed fusion parts. This variation is due to local changes in cooling rates and thermal gradient direction when varying the part geometry. Understanding and controlling this phenomenon is crucial towards optimizing the properties of a printed part. This microstructural control can be utilized when applied to a material which has differing phases with distinct advantageous properties (such as strong & brittle versus weak & ductile), that can be tuned locally to optimize the overall part. We demonstrate this understanding and control in a dual phase 17-4 precipitation hardened steel, quantify the differences in mechanical properties between the microstructures, and determine the ability and scale of microstructural control. Control of local and bulk properties by tuning the microstructure are observed.

952 - Printing Thin Walled Structures in Af9628
Daniel Popovich, Ohio State University

Af9628 is a low carbon, low alloy, high strength steel designed by the Air Force for use in bomb housings. As part of a weight saving process, this project’s aim is to design parameters for printing thin walled structures using blown powder directed energy deposition that eliminates the cracking behavior previously demonstrated by the material. Prints were made on a Trumpf Trulaser Cell 3000, optical and electron microscopy was used to assess density and grain structure. Tensile and fatigue testing was done to confirm retention of desired mechanical properties.

957 - Effects of Process Parameters on the Fatigue Life of Ti-6Al-4V via Laser Powder Bed Fusion
Brandon Ramirez, University of Texas at El Paso

Additive manufacturing via Laser Powder Bed Fusion (LPBF) has already been proven to be a revolutionary technology. For example, the use of Ti-6Al-4V, a popular titanium alloy due to its favorable strength to weight ratio, has already been implemented in the aerospace industry for various parts. However, the validation of quality in additive manufactured parts has always been an issue for concern, specifically under cyclic flexural loadings. This project examines the fatigue behavior of Ti64 printed at various process parameters to both induce defects and create dense components. 45 samples were printed within the keyhole, process window, and lack of fusion regions and cyclical bending loading experiments were conducted to investigate the effects of these defects on the as-built surface. Data is presented as a family of curves depicted by their stress level and total cyclical life, arranging them by printing parameters for comparison under flexural conditions.

Poster B: Processing

045 - High-Throughput Materials by Design Framework Utilizing Experimental and Computational Tools
Sean Fudger, U.S. Army Research Laboratory

Traditional material discovery and development follows an Edisonian approach of trial and error yielding few significant improvements at intermittent intervals. The purpose of this research is to utilize machine learning (ML) to help guide the material development process, particularly focusing on using computational techniques to explore complex multifactorial experiments in addition to data collection and analysis. We will demonstrate high-throughput material science concepts applied to development of complex concentrated alloys (CCAs). By harnessing computational modeling and automating processes, material discovery, synthesis, characterization, and testing can be rapidly accelerated.

070 - Development of Localized Laser Preheating of AA6061 Powder as a Selective Laser Melting Technique to Improve Mechanical Properties of 3D Printed Parts
Conner Larocque, Lehigh University

AA6xxx series aluminum alloys have long been used in industrial applications for their high strength-to-weight ratio, weldability, and relatively low cost. While there is industrial interest in additive manufacturing (AM) of high-strength aluminum alloys, the process comes with several technical challenges stemming from AA6xxx series material properties. While some selective laser melting (SLM) machines are equipped with heated powder systems, many do not operate at optimal temperatures for aluminum alloys. The research aims to develop novel methods of reducing thermal gradients in selective laser melting of AA6061 via localized laser preheating of the powder bed to limit micro crack formation. Local laser preheating consists of sequential low-energy passes to add heat to desired areas. The effectiveness of this process and its contribution to the AM process were then evaluated through microstructure analysis as well as mechanical testing.

134 - Copper Heat Sinks: Design and Fabrication via Sinter Based Material Extrusion (MEX) 3D Printing
Kameswara Pavan Kumar Ajjarapu

Copper heat sinks, especially for electronic applications, are typically manufactured using conventional techniques such as bonding, forging, folding, skiving, or machining. Such heat sinks tend to have simple fin/pin structures, partly attributed to the limitations of conventional processing technologies. In this work, we utilize topology optimization to overcome challenges in transforming decade-old traditional sink of heat design using the sinter-based material extrusion (MEX) 3D printing process. In this work, we developed a >90wt.% copper powder-filled polymer filaments to fabricate thermally efficient heat sink designs that were MEX 3D printed and subsequently processed to remove polymer (debinding) and sintered to achieve dense copper parts. It was identified that thick and thin features in heat sinks tend to debound at different rates due to the differences in surface area and amount of binder material that needs to be removed. Although this differential behavior poses challenges with retaining part integrity post debinding and sintering, it can be overcome using techniques such as topology optimization. Therefore, this study looks at understanding the structure-material property relationships behind 3D printing copper heat sinks by MEX-3D printing process by implementing topology-optimized designs that were tested for their thermal efficiency using simulation and experiments.

135 - On the Effect of Building Platform Material on Laser-Powder Bed Fusion of a Ni-Base Superalloy HAYNES® 282®V
Abdul Shaafi Shaikh, EOS Finland

Additive manufacturing (AM) by laser powder bed fusion (LPBF) involves melting of layers of powder onto a substrate, called a building platform. Due to cost or convenience considerations, building platform materials rarely match the LPBF material, especially for high temperature materials. To ensure tolerances in component geometries, AM components are often stress-relieved / heat-treated while still attached to the building platform. It is therefore important to understand the effect of dissimilar building platform materials on properties of the built-up material. These effects may be particularly important for high performance materials such as Ni-base superalloys used for critical applications in the aerospace and energy industries. To investigate this effect, samples of a Ni-base superalloy HAYNES® 282® were built onto a carbon steel building platform in several configurations. The samples were removed from the building platform after heat treatment and subjected to detailed composition analysis and microstructural characterization to investigate the effect of the building platform material on the properties of the additively manufactured part. Room temperature and high temperature tensile testing were used to characterize the material. Results showed no risk of large-scale chemical composition change, or mechanical property degradation of built-up material from on-platform heat treatment.

145 - Binder Jet Printing of Ti-6-Al-4V with Ultra-Fine Microstructure
Nathan Jump, University of Utah

Binder Jet Printing (BJP) has recently emerged as a feasible manufacturing method for small to large scale parts, but currently, the full capabilities of this technology have some restrictions. Titanium is one of the most desirable materials used in manufacturing due to its high specific strength, high ductility, corrosion resistance, and biocompatibility, yet at this time, titanium still presents a plethora of difficulties that impede its scaled production via BJP. Many of these difficulties are rooted in the fact that powder metallurgy (PM) Ti parts often have too coarse of a microstructure to compete with its wrought counterpart. Therefore, by integrating the Hydrogen Sintering and Phase Transformation (HSPT) process into BJP there is an opportunity to produce relatively low-cost PM Ti parts with comparable strength and ductility. The following research is a summary of the integration of HSPT with BJP along with the improvements provided by hot isostatic pressing (HIP).

901 - The Effects of Sintering Conditions on the Explosion of CW0350 Parts
Julie Hedlund, Penn State DuBois

Powdered metal parts molded from CW0350 mix were observed to explode during the sintering process. This, in turn, has caused a high scrap/material waste during production. This study was conducted to determine the root cause in order to reduce the amount of scrap created from exploding parts by at least 2%. Part samples were tested at different furnace conditions (sintering temperature, atmosphere, and belt speed) and then compared to a controlled sample ran at typical router specifications. When the results of the tests were compared to the standard, the samples that ran with an increase of 50CF hydrogen, a 50°C increase in temperature, or a 1.0 inch/min slower belt speed showed the highest percentage of success. These tests yielded zero exploded parts during their run which reduced the fall out percentage from an average of 6% to 0%.

903 - Characterization and Validation Experiments for a Binder Jet 3D Printing Modeling Framework
Wesley Combs, Rice University

Binder Jet 3D Printing (BJ3DP) is a form of additive manufacturing that utilizes a polymeric aqueous-based solution to bind powder particles into primitives which layer-by-layer compose “green parts”. The Particle Flow and Tribology Lab can simulate this process and is interested in understanding what jetting phase parameters (nozzle translation speed, jetting frequency, particle size) affect important green part qualities (saturation, primitive morphology, green part strength). My project focused on creating a robust experimental validation rig to substantiate our lab’s simulated results while designing and 3D printing a fixed-funnel configuration to measure the angle of repose (AoR) of nickel alloy powders of various particle sizes, an important simulation input parameter. I constructed a BJ3DP assembly including a powder bed structure and printhead holder with a graphical user interface for actuation and control. I also built a fixed-funnel AoR test configuration. Both assemblies garner invaluable experimental results that matched well with simulations.

904 - Finite Element Modeling of Aluminum Alloy Sintering of Metal Binder Jetting Parts
Nicholas Queiroz Avedissian, Ohio State University

Metal Binder Jetting (MBJ) additive manufacturing (AM) has been expanding its industrial applications due to high production rates when compared to other AM processes. A key challenge with MBJ is that the as-printed part is not fully dense and requires sintering after printing. The parts can incur significant shrinkage and distortion during sintering. In the literature, extensive work has been done in numerical modeling of stainless steel sintering. However, aluminum alloy, another important structural metal, presents a significant difference as the sintering is done above the solidus temperature (also called liquid phase sintering). There is limited knowledge on material behaviors such as grain growth kinetics, and viscous- or creep-like deformation at those high temperatures. In this work, literature on aluminum alloy sintering was critically reviewed and then utilized in an existing elastic-viscoplastic continuum model. The effect of sintering parameters on shrinkage and distortion was computed and validated against literature data.

905 - Modeling Air Pressure Development in Compacted Powders
Joseph Wright, Drexel University

Entrapped air within powder compacts has the potential to develop defects for materials with weak cohesion, reduce the overall compact strength even when an observable defect is not formed. Recently computational methods have been proposed to model the air pressure gradient developed throughout the particulate compact.  To complement prior modeling work, we built a specially developed apparatus that measures the volume of air expelled during compaction and can be used to validate estimates of the internal air pressure distributions and to provide an estimate of the powder permeability, which is necessary for the calibration of the model.  This work also provides realistic estimates of the internal stress conditions within the compact and can be the basis for the prediction of strength reduction due to the presence of the entrapped air.

906 - Cold Sintering of Iron Powders for Use in SMCs Using Copper Ferrite Surface Modification
Linsea Foster, Penn State DuBois

Cold sintering of metals is explored using aqueous chemistry and heated compaction. Various surface modification methods have been used for studying cold sintering techniques. The application of surface modified particles in warm compaction has shown enhanced strength properties through various mechanisms. Here we explore use of copper ferrite coatings to enhance the strength and magnetic properties of iron for use in soft magnetics composites. The challenge with SMCs is producing a material that is both electrically insulating and exhibits adequate strength. By applying an electrically insulating layer, such as copper ferrite, and applying cold sintering technique, it is expected that both relatively high electrical insulation and strength may be achieved. The greater the electrical insulation, the more magnetically efficient it can operate in electric motors. The size requirements for producing SMCs will be dependent on its efficiency, so producing magnetically efficient motors is prudent to producing lightweight electric motors.

Poster of Merit Award

907 - Increasing Part Density and Strength in Metal Binder Jetting Through Lattice Infill Patterning
Amanda Wei, Virginia Tech

Use of a liquid binding agent is critical for forming part shape and providing green part strength in metal binder jet (BJ) additive manufacturing (AM). Traditionally, binder is homogeneously deposited throughout the entire part cross-section during printing. However, recent research suggests that reducing the quantity of binder present through a shelled part design increases sintered part density over that of the conventional solid binder infill. Consideration of the reduction in green part properties as a result of reduced binder usage should be explored as well. In the present work, a binder patterning strategy comprised of a contour shell with various internal lattice or TPMS infill patterns are applied to 316L stainless steel powder to balance the tradeoff between green and sintered part properties. In particular, an octet infill was found to have 14% of the green part strength of a traditional solid infill, but a 36% higher sintered flexural strength.

908 - Additive Manufacturing of FeCrAlY Open Porous Structure Using Si3N4 as a Foaming Agent.
Sakineh Abbasi, Oregon State University

The aim of this study is the additive manufacturing (AM) of 316L stainless steel open porous structure to play the role of catalytic substrate for bioconversion applications. For such applications, the 3D morphology, and in particular the surface area, will strongly determine the performance. This study used a novel foaming agent, Si3N4, to produce interconnected pores made by laser powder bed fusion (LPBF). Unlike classical functional design for AM, the open pores considered in this study are the result of fabrication parameters (e.g. scanning laser speed) and not from a CAD design. This work shows that the scanning strategy and process parameters have a major influence on the resulting surface area and volume of open porous structures. Therefore, the presented findings may pave the way to add a higher level of functionality to the additive manufacturing of porous metal samples.

912 - Process-Structure-Property Relationships of Stainless Steel 316L DED Specimens
Matthew Engquist, California State University, Los Angeles

Directed Energy Deposition (DED) is a metal additive manufacturing technique that offers much higher deposition rates than Powder Bed Fusion (PBF) style methods. It accomplishes this partly by incorporating much larger melt pool sizes when depositing material. This increase in melt pool size results in a solidification rates and temperature gradients which results in a unique microstructure and associated mechanical properties. This study investigates the microstructure and properties of 316L austenitic stainless steel produced by the wire laser DED process on a Meltio M450 system. The end goal is to elucidate the process-structure-property relationship of this technique as it shows promise in rapid manufacturing for aerospace.

914 - Heat Treatment and Microstructure Evolution of LPBF Fabricated Ti-6Al-4V
Tristan Armstrong, University of Utah

LPBF is a frontier for the time-efficient and precise manufacturing of geometrically complex parts for a wide range of industries. LPBF fabricated parts have unique microstructures that differ significantly from the microstructure of wrought parts. Understanding how heat treatment parameters influence the microstructure of LPBF fabricated parts is a critical step toward achieving comparable or even superior mechanical properties to wrought parts. Presented is a qualitative analysis of the microstructural evolution of LPBF fabricated parts subjected to heat treatments of varying temperature.

918 - Comparative Analysis of Ultrasonic- and Gas-Atomized Al Feedstock Powders by X-Ray Microscopy and Automated Classification
Daniel Sinclair, Purdue University

In the laser powder bed fusion (LPBF) of metallic parts, powder morphology can negatively impact powder bed consistency and, subsequently, defect formation. Powder production processes vary in their ability to optimize morphology and size, leading to questions of quality control in LPBF manufacturing. Ultrasonic atomization, which forms droplets from a vibrating liquid, is compared to gas atomization, which vaporizes a molten stream. AlSi10Mg powders made with both methods were visualized using lab-scale X-ray microscopy. A set of dimensionless shape factors were collected for over 4,000 particles, and machine learning was trained to automatically apply a user-defined classification scheme based on features of interest. In the ultrasonic powder, overall sphericity was increased but coincided with an increase in pore size. This work additionally outlines a minimally intensive workflow based on automated measurement techniques and a classification method that can be trained on disparate particle species, ultimately reducing human input.

919 - Synthesis Refinement of Al/Ca PM-DMMCs for Overhead Conductors
Dustin Hickman, Iowa State University

A unique synthesis of low-temperature solid-state consolidation of Al and metallic Ca utilizing a powder metallurgy (PM) route are being explored for use in developing high-voltage DC overhead transmission conductors. To increase the extrudability without utilizing a sealed can material, densification was explored utilizing 12-21ksi pressure and temperatures up to 180C without transforming metallic Ca to hard Al/Ca intermetallics for subsequent consolidation and deformations. Wire samples with three levels of deformation true strain were synthesized and characterized through this PM route. These single wires retained competitive, repeatable material properties compared to commercially available overhead conductors with potential for even greater strengths. The results presented serve as a proof of concept for achieving greater strengths from simply decreasing the Ca powder size distribution utilized for the Al/Ca wire synthesis whilst minimally affecting electrical conductivity. Funding from DOE-OE through DE-AC02-07CH11358.

921 - SS316L and 17-4 PH Bimetallic Structures Using Powder-Based Laser-Directed Energy Deposition
Aruntapan Dash, Washington State University

The present research is focused on developing novel bimetallic structures of 17-4 PH and SS316L stainless steels. SS316L powders with particle size 53-150 µm and 17-4 PH powders with particle sizes 15-53 µm are used as feedstock material in a powder-based L-DED metal AM system (FormAlloy, Spring Valley, CA) for printing the samples. Five different compositions, including single and multilayer bimetallic structures, were printed using the feedstock materials with optimized process parameters for each. The printed bimetallic structures have not shown any macro defects. Printed samples were subjected to phase and microstructure characterization. Primarily austenite (γ) and martensite (α) phases are observed in the printed samples. Microstructural analysis revealed the formation of columnar, cellular, and equiaxed dendrites in the SS316L and martensitic structure in 17-4PH. Microhardness and compression tests were performed with these samples to understand how the layering sequence controls the deformation behavior.

923 - Optimizing Selective Laser Melting AM Parameters for Printing Thin-Walled Structures for Pressurized Applications
Peyton Archibald, California Polytechnic State University, San Luis Obispo

Selective Laser Melting (SLM) is a widely used additive manufacturing technology that offers great potential for producing complex geometries and functional parts. However, the optimization of printing parameters for thin wall parts that can withstand pressurized applications and ensure leak-free performance remains a challenging task. This study aims to optimize the printing parameters of an SLM 3D printer to produce thin wall parts for pressurized applications with improved leak-free performance. The printing parameters were systematically varied and their effects on the part's wall thickness, surface quality, and leak-tightness were analyzed. So far, the results show that optimizing the scan strategy of the laser is crucial in creating functioning, leak-tight parts. This study aims to provides valuable insights for optimizing the printing parameters of an SLM 3D printer to produce thin wall parts suitable for pressurized applications.

925 - Properties of Green and Sintered FC-0208 Using HGS 2.0
Cole Bressler, Penn State DuBois

Improved green strength and lower ejection forces means less broken green parts as well as the ability to machine green parts, reducing the wear on tooling. With the use of High Green Strength Second Edition (HGS 2.0) lubricant these desired properties could be achieved. A new proprietary lubricant, HGS 2.0, is being tested to determine its properties when used in the powdered metal process. This research is presenting the properties of HGS 2.0 lubricant as well as green and sintered parts of FC-0208, 316 stainless steel, and 304 stainless steel blended with this new lubricant. The FC-0208 samples were pressed to densities of 6.8g/cc, 7.0g/cc, and 7.2g/cc. The stainless-steel samples were pressed to densities of 6.3g/cc. 6.4g/cc, 6.5g/cc, and 6.6g/cc.

926 - Construction of a Customized Inkjet 3D Printer
Andrew Gillespie, Indiana University-Purdue University Indianapolis

In this work, the construction of an open-source inkjet printer. This printer utilizes a layer-by-layer droplet interaction and heat to help bond particles with the potential for ceramic and electrical components fabrication. The project's focus is on developing 3D printing of a component efficiently. The primary feedstock used in this procedure is powdered, granulated sugar with a mix of alcohol and food coloring to act as a bonding agent. The project demonstrates the efficiency and limitations of inkjet printing and the printing materials used. On-going experiments include improving the printer head, powder, and binder recipes, allowing us to find an efficient and cost-saving additive Manufacturing ceramic 3D printing technique.

927 - Using Simulation as a Supplemental Resource for Minimizing Sintering Distortion of BJP Parts
Nicholas Engstrom, University of Utah

Binder Jet Printing (BJP) of titanium is a promising additive manufacturing method for producing parts with high surface detail and physical properties. However, sintering can cause distortion and non-uniform shrinkage. Empirically optimizing part design and sintering parameters for each individual part is impractical. Simulation software can supplement the process to minimize sintering distortion by predicting shape change during sintering based on known titanium properties. This allows for part modification prior to sintering, with the prediction being confirmed through experimentation. This method builds on itself, which leads to further refinement of the simulation parameters for titanium for each iteration. This approach enables engineers to make informed decisions when designing titanium parts for BJP, leading to a more generalizable approach to minimizing sintering distortion.

929 - The Impact of Various Post-Processing Techniques on the Flexural Bending Fatigue Life of Additively Manufactured Aerospace-Grade Titanium Alloy (Ti-6Al-4V) Parts
Cristian Banuelos, University of Texas at El Paso

The aim of this project is to assess the effects of different surface finishing techniques of additively manufactured metal parts with relation to their fatigue life as they undergo bending loading. Laser powder-bed fusion technology was used to manufacture aerospace grade titanium alloy (Ti-6Al-4V) parts under standard manufacturing conditions. The parts were heat treated for stress relief and were then randomly assigned to the different surface finishing procedures to achieve an optimal testing geometry and improve the surface finish. The surfaces of the specimens were given a quality inspection and roughness measurements were taken using optical and mechanical approaches prior to mechanical testing. The specimens were subjected to four-point bending fatigue testing until fracture and the data was used to generate S-N curves; the fracture surface was also analyzed to better understand the failure mechanisms and the end use performance of the material under the various surface finishes.

930 - Comparison of Surface Texture Analysis Methods for Additive Manufacturing  Laser Powder Bed Fusion
Alex De La Cruz, University of Texas at El Paso

Powder particles contribute to the as-built surface textures produced by additive manufacturing technologies. These surfaces attain irregularities, one common feature that can be distinguished is unmelted particles, which cause an apparent increase in roughness, leading to subpar mechanical performance and efficiency. Roughness measurements depict how flat and smooth the surface is. While machining is commonly used to eliminate the high roughness from AM-produced components, its capabilities are still limited for complex geometries. Using Laser Powder Bed Fusion (L-PBF) machine, Ti-6Al-4V samples were printed by altering the speed and power of the laser generating different textures. The as-built surface performance was tested by conducting four-point bending tests.  Three surface texture measurements were compared: X-ray tomography, microscopy, and profilometer.  The study emphasizes comparing these techniques, aiding current research on establishing a method in which the surface texture can be measured concisely and recognizing the application, and comparing the measuring technologies.

931 - Process-Microstructure-Property Relationships in Laser Powder Bed Fusion of Non- Spherical Ti-6Al-4V Powder
Mohammadreza Asherloo, Illinois Institute of Technology

An investigation of process-microstructure-property relationships in Ti-6Al-4V parts processed using laser powder bed fusion of non-spherical powder showed full control over porosity

content, surface roughness, microstructure, texture, and hardness. Increasing laser scan speed from 400 mm/s to 1500 mm/s eliminated the keyhole porosities and enhanced relative density to ~99.8 %. Also, the surface roughness (Sa) decreased from 119 μm to 21.8 μm. Microstructural observations showed that the primary beta grains were refined, and their shape factor increased from ~2.5 to ~5. Additionally, the hardness reached a maximum of 390 HV 0.5 when the scan speed was 1250 mm/s. An increase in laser power from 225 W to 370 W slightly changed the Sa between 16.2 - 21.43 μm. Additionally, the hardness increased from ~355 HV 0.5 to ~383 HV0.5 with increasing laser power. Synchrotron X-ray high speed imaging also showed the direct correlation between the melt pool depth and the texture intensity.

932 - Influence of Printer Design and Printing Parameters on Ballistic Ejection
Jacob Feldbauer, Penn State DuBois

Binder Jet Additive Manufacturing (BJAM) is a versatile powder bed technique that uses a binder deposited using ink jetting to form complex components. Ballistic ejection occurs during the application of the binder to the powder bed layer during the binder jet printing process.  The momentum of the binder droplet impacting the powder bed results in a disturbance of the powder layer.  This disturbance of the particles in each layer causes inconsistencies in the density and bonding during the sintering step of the process, resulting in a localized disruption in the uniformity of the materials properties.

The printer design and the parameters used to print influence the size and momentum of the binder droplet.  The influence of these parameters will be reviewed to minimize ballistic ejection during printing and improve the quality and uniformity of the printed components. We use X-Ray computed tomography to study the differences in 17-4 steel parts as printed in the green state. This information will be critical for understanding the evolution of inhomogeneity in sintered components and their role in material properties.

936 - Development of a Novel Multi-Laser Scan Strategy to Reduce Micro-Cracking in Additively Manufactured Tungsten
Emmaline Hutchison, Ohio State University

Additive Manufacturing (AM) has seen a substantial rise in popularity over the past decade due to its increase in design freedom, the reduction in product development time, and its ability to address supply chain gaps. However, certain materials present issues when it comes to AM due to their unique material properties and laser powder bed fusion’s (L-PBF) inherent laser welding processes. Tungsten is one such material: it is difficult to machine and often cracks as it sheds the heat from L-PBF builds. This study examines the effects of a multi-laser melting and cooling processes on the material properties of tungsten parts. Metallographic analysis of printed samples was conducted to track the density across the builds. The use of a leading laser was observed to significantly contribute to the increased density of samples when compared to single laser builds.

938 - Application of Additive Manufacturing to Deliver Incremental Production of Conventional Powder Metal Components Without Compaction Tooling
Hope Spuck, Penn State DuBois

The conventional powder metal industry has always struggled with distributing the cost of compaction tooling and the need to maintain a competitive price of the final product. The result has historically limited the order size to high volume orders.

Although additive manufacturing of metal components has become more accepted. Additive techniques, such as laser powder bed fusion and traditional binder jet printing, have been focused on the production of small spherical particle sizes and materials that are less susceptible to oxidation, like 316 and 17-4. This has prevented the application of AM as a low volume process to complement the conventional press and sinter production of traditional powder metal chemistries and parts.

Recently, a new approach to additive manufacturing has provided a technique for the printing of conventional powder metal chemistries and particle size distributions. Using an FC-0208 powder, the physical properties and processing requirements will be reviewed to assess the application of this printing technique to expand the market for conventional press and sintering manufacturing.

940 - Additive Manufacturing of Aluminum Alloy by Metal Fused Filament Fabrication (MF3)
Sihan Zhang, University of Louisville

This research investigated additive manufacturing of Al-6061 aluminum alloy via metal-fused filament fabrication (MF3). This work focused on using the MF3 process to fabricate Al-6061 test coupons and optimize the MF3 process parameters to obtain improved mechanical properties. Feedstock with 57 vol.% solids loading Al-6061 was prepared by mixing Al-6061 powders and a polymer binder, followed by extrusion to fabricate a filament with a 1.75 mm diameter. The 57 vol.% Al-6061 powder-polymer filament was used to print green tablets and tensile bars with a Prusa MK3S+ 3D printer. Experiments were designed to optimize the 3D printing process parameters to obtain parts with the highest green densities. The green parts were subjected to solvent debinding, thermal debinding, and, finally, sintering processes to remove polymer content and become dense Al-6061 tablets and tensile bars. The sintered parts were characterized for grain structure, sintered density, and mechanical properties, and their prosperities were compared to metal injection molded (MIM) specimens. This work aims to enable rapid, predictable, reproducible, low-cost, and accurate production of metal parts with 3D features, thereby significantly expanding the current additive manufacturing capability.

941 - Machine Learning in Powdered Metallurgy
Cole Walker, University of Utah

There are many areas in powder metallurgy that can benefit from the implementation of machine learning. One of these areas is the determination of particle size, which can be done in multiple ways, but a highly accurate technique is using image analysis. Extracting the size from images can be time-intensive, and using machine learning to identify overlapped particles and accurately extract results can be extremely useful and efficient. Other applications of machine learning in powder metallurgy include investigating different material possibilities and optimizing powder synthesis and production processes. These applications are discussed, including their ease of implementation, scalability, accuracy, and potential.

947 - Development of Localized Laser Preheating of AA6061 Powder as a Selective Laser Melting Technique to Improve Mechanical Properties of 3D Printed Parts
Conner Larocque, Lehigh University

AA6xxx series aluminum alloys have long been used in industrial applications for their high strength-to-weight ratio, weldability, and relatively low cost. While there is industrial interest in additive manufacturing (AM) of high-strength aluminum alloys, the process comes with several technical challenges stemming from AA6xxx series material properties. While some selective laser melting (SLM) machines are equipped with heated powder systems, many do not operate at optimal temperatures for aluminum alloys. The research aims to develop novel methods of reducing thermal gradients in selective laser melting of AA6061 via localized laser preheating of the powder bed to limit micro crack formation. Local laser preheating consists of sequential low-energy passes to add heat to desired areas. The effectiveness of this process and its contribution to the AM process were then evaluated through microstructure analysis as well as mechanical testing.

948 - Spherical Ti-6Al-4V Alloy Powder Made by the Direct Reduction and Alloying (DRA) Process
MD Emran Hossain, University of Utah

Spherical Ti-6Al-4V alloy powder is one of the most demanding feed materials for additive manufacturing to produce near-net-shaped products. Atomization is the most used technique today to produce Ti-6Al-4V spherical powder, but high production cost drives the emergence of low-cost processes. Some new methods have been developed to produce spherical Ti-6Al-4V alloy powder; however, no process has been claimed to make it directly from raw oxides. This research demonstrates a novel pathway to make spherical Ti-6Al-4V alloy powder directly from basic oxides by hydrogen-assisted magnesiothermic reduction (HAMR). Raw metal oxides are mixed uniformly and reduced to form fine Ti-6Al-4V alloy powder, which is then granulated-sintered and deoxygenated (GSD) to produce the spherical powder. The process is called the direct reduction and alloying (DRA) process. Spherical Ti-6Al-4V alloy powders produced by this process have low interstitial impurities, controlled particle size distribution, uniform and homogeneous composition, and excellent flowability.

949 - Post-Processing Effects on Mechanical and Corrosion Behavior of Additively Manufactured 7050-Based High Strength Aluminum Alloy
Rupesh Rajendran, Georgia Institute of Technology

Additively manufactured(AM) high strength aluminum alloys are highly attractive to the aerospace industry due to inherent benefits of the AM process in addition to the alloy benefits such as high strength to weight ratio, corrosion, and fatigue resistant properties. Recent addition of inoculants or nanoparticles have reduced solidification defects in high strength aluminum alloys which was a bottleneck for adoption of these alloys. This work is focused on understanding the effect of post-processing treatments such as stress relieving, hot isostatic pressing(HIP), and solutionizing and aging on the mechanical and corrosion behavior of a 7050-based high strength aluminum alloy. Extensive characterization and mechanical tests are done to understand the effect of post-processing treatments. The result of this work is beneficial for optimization of post-processing treatments for target mechanical and corrosion performance. An equivalent wrought alloy is compared for understanding the differences and similarities between additive vs. wrought alloys for targeted application.

950 - Development of a Rapid Testing Method for Metal Additive Manufacturing
Keita Shimanuki, California Polytechnic State University, San Luis Obispo

Due to its infancy in industrial application, metal additive manufacturing process development is a vital area of research to produce high quality parts and increase production rate. Tensile and fatigue tests have been the dominant testing methods for qualification of process parameters. However, the amount of time and cost required to gain statistically significant data, especially when dealing with hundreds of different process parameter permutations, is an obstacle. Development of a go/no-go test method designed as a first pass filter for process parameters will increase efficiency in the development stage.

This experiment will utilize a drop weight impact test method, which is a mechanical test where a qualitative result, such as crack propagation or complete failure, can be obtained from the impact. To better resemble the dynamic nature of the impact test, a high strain rate tensile test will be used as a reference to find any correlation.

954 - Binder Jet Printing of Ti-6Al-4V with Ultra-Fine Microstructure
Nathan Jump, University of Utah

Binder Jet Printing (BJP) has recently emerged as a feasible manufacturing method for small to large scale parts, but currently, the full capabilities of this technology have some restrictions. Titanium is one of the most desirable materials used in manufacturing due to its high specific strength, high ductility, corrosion resistance, and biocompatibility, yet at this time, titanium still presents a plethora of difficulties that impede its scaled production via BJP. Many of these difficulties are rooted in the fact that powder metallurgy (PM) Ti parts often have too coarse of a microstructure to compete with its wrought counterpart. Therefore, by integrating the Hydrogen Sintering and Phase Transformation (HSPT) process into BJP there is an opportunity to produce relatively low-cost PM Ti parts with comparable strength and ductility. The following research is a summary of the integration of HSPT with BJP along with the improvements provided by hot isostatic pressing (HIP).

955 - Optimizing Repairs of Aluminum 7075 via Directed-Energy Deposition
Dylan Treaster, Penn State DuBois

Aluminum 7075 is a precipitation hardening alloy known for its high strength to weight ratio desirable ductility, and fatigue properties making it an alloy of choice for many critical applications. However, components built of Al7075 are often subjected to harsh environments over their service life ultimately leading to corrosion, and consequently the need for repair. Repairing Al 7075 is often unattainable via traditional arc-based welding techniques. Weld repairs exposes the material to high temperatures which in turn produces elemental segregation that leads to liquation and solidification cracking which is attributed to low-melting point alloying elements such as zinc and magnesium. This study focuses on the repair of Al 7075 via laser-based directed energy deposition, additive manufacturing. Laser-based directed energy deposition has the ability to control the energy source by tailoring the laser spot size, power, and process mode (continuous wave or pulsed wave) along with the ability to employ various feedstock which allows for process optimization to alleviate cracking thereby making repair fabrication viable. Parameter development and process optimization were conducted to decrease the material debit in the base structure and provide a quality repair.

960 - Project MANTLES
Darren Takaoka, Ohio State University

NOTE: Pending Approval for Public Release.

The MANTLES project is an ongoing partnership between NCDMM, Ohio State University's Center for Design and Manufacturing Excellence, industry Partners including Hexagon 3D, Collin's Aerospace, Northrop Grumman, Lockheed Martin and Ursa Major. The scope of the project was to create and optimize a workflow leveraging both Post Process Imaging and prebuild simulation to reduce distortions in Laser-Powder Bed Fusion Parts. This workflow is to be used to achieve smaller Geometric Tolerances in the Produced Parts. The Parts were Printed at CDME on an EOS M290 in Inconel powder, 3D Scanned by a Hexagon 3D laser Scanner. The geometries to be printed and analyzed was initially a Rocket nozzle with complex internal geometries supplied by Ursa Major but was later replaced by a less structurally stiff duct part drawn up at CDME to observe a greater initial distortion.

Poster C: Properties

Outstanding Poster Award

105 - Use of Artificial Intelligence to Characterize the Rheological Properties of Water Atomized Powders Developed for Laser Powder Bed Additive Manufacturing
Gabrielle Laramée, Laval University

Laser powder bed fusion (LPBF) requires the use of powders having good fluidity, which are usually produced by gas atomization. Although water atomized powders can be tailored to achieve rheological properties like those of gas atomized ones, a single powder can exhibit a wide range of particle morphologies. Herein, the objective was to use machine learning (ML) to correlate the distribution of particle morphologies with the rheological properties of several powder lots. The ML pipeline employs an unsupervised algorithm to group together visually similar particles, creating a particle shape distribution for a given powder. Contrary to traditional image analysis, the proposed methodology could be used to understand how the presence of certain types of particles impacts the rheological properties of a powder. This work shows how ML represents a powerful tool to optimize the fluidity of powders for LPBF, thus contributing to the manufacture of higher quality parts.

165 - Process-Microstructure-Property Relationships in Laser Powder Bed Fusion of Non-Spherical Ti-6Al-4V Powder
Mohammadreza Asherloo, Illinois Institute of Technology

An investigation of process-microstructure-property relationships in Ti-6Al-4V parts processed using laser powder bed fusion of non-spherical powder showed full control over porosity content, surface roughness, microstructure, texture, and hardness. Increasing laser scan speed from 400 mm/s to 1500 mm/s eliminated the keyhole porosities and enhanced relative density to ~99.8 %. Also, the surface roughness (Sa) decreased from 119 μm to 21.8 μm. Microstructural observations showed that the primary grains were refined, and their shape factor increased from ~2.5 to ~5. Additionally, the hardness reached a maximum of 390 HV0.5 when the scan speed was 1250 mm/s. An increase in laser power from 225 W to 370 W slightly changed the Sa between 16.2 - 21.43 μm. Additionally, the hardness increased from ~355 HV0.5 to ~383 HV0.5 with increasing laser power. Synchrotron X-ray high speed imaging also showed the direct correlation between the melt pool depth and the texture intensity.

900 - Effect of Particle Size Distribution on the Physical Properties of Binder Jetted 17-4 as a Function of Print Axis
Nanna Bush, Penn State DuBois

Binder jetting is quickly becoming recognized as one of the most desirable methods to produce high-volume printed components and future printed material development.  Although this technique of printing has been available for a while, the understanding of the impact of particle size distributions on the physical properties of the components and directions in which they are printed remains an area of investigation. 

In this work, 17-4 material of varying particle size distributions will be printed in the X, Y, and Z axes.  Particle size distributions, physical testing, densities, and electron microscopy will be completed to better understand the printing process.

910 - Effect of Machine Variability and Thickness on Microstructure and Microhardness of Laser Powder Bed Fusion (L-PBF) Additively Manufactured Inconel 718 for Aerospace Application
Anannya Doris, University of Texas at El Paso

In this study, sixteen artifacts thin were fabricated by different qualified manufacturers using Laser Powder Bed Fusion (L-PBF). Aimed to evaluate variability between suppliers, thin wall features present in the artifact were characterized. Microstructure and microhardness analyses were conducted to also evaluate its variability with respect to different wall thicknesses. Additionally, Electron Backscatter Diffraction (EBSD) analysis with inverse pole figure (IPF) mapping was done for selected artifacts. The average grain width of the thin walls was in the range of 20-46 microns for the thinnest wall and 50-90 microns for the thickest wall, with the edge layers having narrower grains as a result of a faster cooling rate. The microhardness ranges from 420 to 490 HV for all the thin wall samples. The study closes with a comparison of EBSD grain boundary maps, showing equiaxed grains with a lower threshold angle with smaller grains in the border area.

911 - Consequences of Powder Reuse on Microstructure Evolution During Laser Powder Bed Fusion of 316L Stainless Steel
Madelyn Madrigal Camacho, Colorado School of Mines

Successive reuse processes lead to changes in powder morphology, chemical composition, and microstructure in the recovered powder. In the case of 316L stainless steel, literature reports successful powder reuse within 12-30 consecutive cycles, however, a detailed understanding of the effect of powder degradation on the final part quality is unexplored. Therefore, the primary goal of this study is to enable the rapid degradation of the powder feedstock under conditions which can be transferable to manufacturing processes. With this approach, the effects of the thermally dynamic powder-laser interactions and the instrument process parameters on reused powder characteristics can be explored. The results provide insight to the consequences of the melt pool behavior with the instabilities of the altered powder, solidification modes, microstructure, evolution of spatter and porosity in the as-built components. These observations point to important considerations to design a standard method for reusing powder in powder bed fusion processes.

913 - Physical, Mechanical, and Electrical Properties of Copper Fabricated via Sinter-Based Material Extrusion (MEX) 3D Printing
Kameswara Pavan Kumar Ajjarapu, University of Louisville

This work uses a sintered-based material extrusion additive manufacturing (MEX-AM) process to fabricate high-density copper parts via extrusion-based 3D printing technology. In the current work, copper powder-filled polymeric feedstocks and filaments with 58 vol.% and 61 vol.% solids loading were prepared and characterized for physical, thermal, and rheological properties. Subsequently, the filaments were 3D printed into tensile and tablet geometries via a benchtop MX-AM machine. An L9 Taguchi design of experiments was performed by varying print temperature, print speed, and layer height for three levels to identify optimal process conditions to obtain the highest green density and minimum surface roughness perpendicular and parallel to the build direction. Copper green parts were further sintered and characterized to understand the final part's physical, mechanical, and electrical properties. Microstructure evolution with varying sintering conditions was also studied to identify its influence on final part properties. This study aims to provide a holistic understanding of the structure-property-processing relationship in copper parts fabricated via sintered-based MEX 3D Printing.

915 - Effect of Die Filling Density of Pharmaceutical Powders on Phase Transformation During Tablet Compaction
Phuong Bui, Drexel University

During tablet compaction, initial crystalline of active pharmaceutical ingredients (API) may transform into another crystalline or amorphous state depending on the local stresses. Over the past years, compression induced phase transformations have attracted attention, but there are difficulties in establishing a conceptual framework for understanding and controlling this problem. Prior studies on the polymorphic conversion in tablets typically reported the percent of transformation as a function of applied compaction pressure. However, geometrical characteristics and stress history of the compacted material can also potentially influence these polymorphic conversions.  Our goal is to understand the relationship between the efficiency in die filling density to local variation of the stresses and in turn their effects on the transformations using Chlorpropamide as a model API. The long term of this work is to develop a constitutive model that can optimize the design and processing conditions of materials with potential transformation behaviors during tableting.

916 - Microstructural Characterization of Laser Powder Directed Energy Deposition (LP-DED) Niobium Alloy C103
Brandon Colón, University of Texas at El Paso

Laser Powder Directed Energy Deposition (LP-DED) allows for larger builds compared to Laser Powder Bed Fusion (L-PBF) systems. Recent development efforts by NASA, academia, and industry partners have focused on maturing the use of Niobium-based refractory alloy C103 due to its stability of mechanical properties under high temperatures. This work focuses on the parameter development required to fabricate aerospace propulsion C103 components using LP-DED. A Design of Experiments was performed to identify process parameters that produced thin wall specimens with the highest density and acceptable resolutions. Quantifiable microstructural characterization including melt pool dimensions, porosity, and other features was conducted for the selected specimen. Physical characterization including measurements of surface texture, thickness, and geometrical accuracy is also reported and discussed.

917 - Finite Element Model of Laser Heating Phenomenon in Metal Powder Bed Fusion Process
Hassan Fatahbeygi, Indiana University-Purdue University Indianapolis

In this work, a finite element model is presented which simulates the laser heating phenomenon in the metal 3D printing process. The laser beam shape follows a Gaussian profile. The powder bed is simplified as a porous media with porosity dependent properties. The effects of laser power and scan speeds on melt pool shape and associated temperature fields are studied. The simulation results are compared with literature data.

922 - Effects of Hot Isostatic Pressing on Microstructure and Mechanical Properties of Vacuum-Sintered Gas Atomized Fine 316L Stainless Steel Fabricated via Binder Jetting
Mohammad Jamalkhani, Illinois Institute of Technology

316L stainless steel (SS) has been received attention as a compatible feedstock in binder jetting. However, characteristic remnant pores in the structure of the as-sintered parts decrease mechanical properties. To optimize the sintering profile providing both densities of >99% and dimensional accuracy, the effect of hot isostatic pressing (HIP) on the microstructure and mechanical properties of the binder jetted fine 316L SS powder was investigated. Sintering temperatures ranging between 1340-1430 ℃ and HIP cycles with four combinations of pressure and temperature were selected. After the HIP process, a relative bulk density of 99.43% was achieved at 1370 ℃ reaching a maximum of 99.76% at 1430 ℃. Grain coarsening was seen as the sintering temperature increased reaching its peak of 207.41±5.39 μm at 1400 ℃; however, a slight change in the grain size was detected at 1430 ℃ due to a noticeable amount of delta-ferrite at the grain boundaries.

Poster of Merit Award

924 - Tensile Deformation Behavior of Additively Manufactured IN625 at Different Temperatures: LPBF vs. LP-DED
Arun Poudel, Auburn University

This study compares the tensile deformation behavior of laser powder bed fused (L-PBF) and laser powder direct energy deposited (LP-DED) Inconel 625 (IN625) at -195 °C, 20 °C, 200 °C, 425 °C, and 650 °C. The heat treatment involving stress relieving, hot-isostatic pressing, and solution treatment resulted in equiaxed grains accompanied by annealing twins. Tensile results showed decreasing strength with increasing test temperature in L-PBF and LP-DED which was attributed to the decline of the deformation twin density in the material. However, the tensile strength of LP-DED was lower than L-PBF ascribed to its larger grain size, i.e., nearly three times. The ductility of L-PBF and LP-DED IN625 was observed to be stable from -195 °C to 425 °C; however, a sudden decrease was observed at 650 °C. In LP-DED specimens, the tensile fracture was governed by the decohesion of carbides, whereas it was carbides and Al2O3 in L-PBF specimens.

933 - Investigation of Heat-Treatment Effects on Microstructure and Mechanical Properties of Gamma Ti-Al Fabricated by Electron Beam Powder Bed Fusion
Shadman Tahsin Nabil, University of Texas at El Paso

The aerospace industry requires lightweight, high-strength materials, such as gamma Ti-Al, for improved fuel efficiency and reduced emissions. However, the intermetallic nature of Ti-Al makes traditional manufacturing methods challenging. Additive manufacturing techniques, such as EB-PBF, offer a promising solution, but they can produce parts with heterogeneous and anisotropic microstructures. In this study, Ti-Al was produced using EB-PBF and subjected to HIP and HT to reduce anisotropy. Mechanical testing was conducted to assess the tensile strength of the samples at room and elevated temperatures. The study highlights the feasibility of using AM to produce Ti-Al for future aerospace applications. However, the results also indicate that the microstructure variations resulting from HT could impact the tensile strength of the material. Future research should investigate these effects further to optimize the manufacturing processs.

934 - Data Curation and Analysis for the AM Pipeline: from Powder to Part
Srujana Rao Yarasi, Carnegie Mellon University

The Additive Manufacturing (AM) pipeline is a rich source of data, going from the powder feedstock to the final part. Powder properties such as size and morphology dictate powder behavior in the AM machine, which when combined with machine variables such as processing parameters, heavily influence the part properties like surface roughness and part density. Going from powder parameters to machine parameters to part properties necessitates the creation of a database that includes all the parameter choices that a user makes throughout this pipeline. This database includes the powder property measurements, build parameter choices, and any part properties tested. This will be important in determining the efficacy of the flow metrics in predicting powder performance in the AM machines. Ultimately, this will set a standard for data collection throughout the AM pipeline and help build a framework for analysis going from powder to part through machine learning techniques.

935 - Process/Structure/Properties Relations in LPBF Stainless Steel Lattice Materials Optimized for Energy Absorption
Mahsa Amiri, University of California, Irvine

The objective of this research is to map material microscale features to mechanical properties in a technologically important alloy (SS 316L) produced by laser powder bed fusion (LPBF). Recent evidence suggests that highly enriched dislocation cells are present in the as-printed condition of stainless steel 316 by LPBF suggesting that unconventional features may contribute to property improvements over conventional processing routes. We elucidate how these features are linked to processing parameters in SS 316L. X-shaped samples from SS 316 L powder are manufactured as primitive structures. The geometrical variables under study are strut thickness (0.5, 1, and 2 mm), and strut angle (45 and 60). Structures are manufactured at two different laser parameter sets, resulting in two distinct energy density values. We investigate the resulting microstructures with a variety of advanced techniques, including SEM, EBSD, EDS, CT-Scan, and TEM. Mechanical properties are measured with macroscale compression testing and nanoindentation.

937 - Mechanical Testing and Microstructural Characterization of Laser Powder Bed Fusion (L-PBF) Additively Manufactured Inconel 718 Angled Walls for Aerospace Application
Dana Godinez, University of Texas at El Paso

Laser Powder Bed Fusion technologies have been proved capable of building complex structures. With the purpose of assessing process capabilities and reproducibility throughout Laser Powder Bed Fusion systems deployed in industry, various machines were used to print 16 geometric feature build plates. All vendors were expected to yield similar results, with the process definition and machine configurations typically defined by the manufacturers, some variability in the properties is expected, and is the main subject of this study. A total of 144 unsupported angled wall specimens (at 90°, 60°, and 45°) were subject to this comparison study given the special care to manipulate down skins and up skins. The characterization included density measurements, microstructural analysis, tensile testing, and SEM fractography. This work finalizes with concluding comparisons not only between the angles of fabrication, but between different machine configurations and scanning strategies.

939 - Effect of Process Parameters on Texture Formation During Directed Energy Deposition of 316L Stainless Steel
Amirhesam Shakibizadeh, California State University, Los Angeles

Direct Energy Deposition (DED) process uses powder, wire, or a mix of the two as the feed material. Due to the fast deposition rates, DED enables the production of large complicated functional parts with thin walls. Generally, depending on the material and the instrument in use, a set of optimized processing parameters is established. It is essential to thoroughly investigate the impact of various processing settings on bead geometry and solidification patterns in order to generate high-quality additively produced goods. This study uses 316L stainless steel samples produced by a laser-wire DED system with a six-beam laser head and coaxial wire feed. The effect of processing parameters on the microstructure and texture formation is analyzed and discussed.

942 - Adhesion of Powder onto Tools During Compaction
David Freiberg, Drexel University

During compaction of powder into tablets, the phenomenon known as "sticking", where particles from a powder compact adhere to the tool punch after the punch is unloaded, is a persistent and insufficiently understood problem.  In this work, we use the Discrete Element Method (DEM) to simulate sticking via a non-continuum model for the first time.  With these simulations, we show the importance of inhomogeneity in the onset of sticking, we show that the strength of adhesion between powder and punch is not sufficient to predict sticking, and we show that two materials differing only in interparticle cohesion and powder-punch adhesion can have the same maximum tensile force and yet have opposite sticking behaviors.

944 - Studying the Microstructure and Mechanical Properties of 3D Printed 718 Super-Alloy After Plasma-Enhanced Magnetron Sputtering
Amir Yahyaeian, Indiana University-Purdue University Indianapolis

The use of 3D printed 718 nickel base superalloy is becoming more common in high-temperature applications. To further enhance its mechanical properties, ceramic coatings are applied using the Plasma-Enhanced Magnetron Sputtering (PEMS) technique on both 3D printed and conventionally wrought 718 alloy. In this study, we aim to investigate the microstructure and phase composition of the specimens before and after plasma treatment, employing techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), nanoindentation, and tribometry. Furthermore, we will conduct finite element modeling to support the experimental results.

951 - Leveraging Quantitative Fractography to Estimate Defect Severity from the X-Ray Computed Tomography of Additively Manufactured Titanium
Ian Wietecha-Reiman, Penn State University

Scatter of fatigue life in additively manufactured (AM) components continues to be a challenge in the design for fatigue of AM Ti-6Al-4V. This challenge may be overcome by incorporating quantitative fractography techniques to predict how processing defects, as imaged using x-ray computed tomography (XCT), impact fatigue life. Post-mortem analysis of fracture surfaces using scanning electron microscopy and confocal white light interferometry reveal important geometric relationships that can be used to model the fatigue crack growth and radius of curvature of processing defects. Metrics derived from these relationships are then assessed using survival analysis statistics which both rank processing defects based on relative severity and provide estimates of fatigue life. Actual specimen fatigue lives correlated well to the knee bend of the survival analysis curves and were used to establish confidence intervals for expected fatigue life.

953 - Leveraging Design for Additive Manufacturing to Remedy Low Internal Porosity in Metal Powder Binder Jetting
Daniel Juhasz, University of Waterloo

Metal binder jetting additive manufacturing (BJAM) is a powerful AM technology capable of producing highly complex metallic parts. However, the high porosity of sintered parts is an ongoing technological limitation, which must be addressed. In this study, we propose addressing core porosity using a design-driven approach. We investigate the feasibility of printing gas flow channels within 4405 low-alloy steel parts and their effects on core porosity. To this effect, solid body blocks were manufactured alongside hybrid lattice/solid blocks, each encapsulating near-shape tensile specimens in their solid regions. High-resolution computed tomography (CT) data will elucidate the efficacy of enhanced gas flow through the lattice architecture vs. solid block in mitigating entrapped porosity in the gage section of specimens. Additionally, low-resolution CT and microscopy will elucidate the influence of the solid-lattice boundary interface on geometric fidelity of specimens. Lastly, tensile testing will demonstrate the mechanical performance of the two classes of specimens.

956 - A Comparison of the Mechanical Behavior of AlSi7Mg Alloy Produced Through Additive Manufacturing and Subjected to Different Heat Treatments
Kevin Caballero, University of Texas at El Paso

Aluminum F357 (AlSi7Mg) is popular in aerospace and defense due to its versatility. In this study, two laser powder bed fusion systems were used to create specimens of Aluminum F357 and subjected to five heat treatments. The specimens were then reduced to tensile bars and tested for mechanical properties. In addition, the study used an SEM to observe the fracture produced by the tensile test and a microhardness machine to obtain hardness (HV) values. The results showed that the specimens fabricated in the Z direction had higher yield strengths and that heat treatment had a significant impact on mechanical properties. The study highlights the importance of heat treatment in optimizing processes and producing high-quality components in the aerospace and defense industries. The compatibility of LPBF system fabrication and the mitigation of differences between LPBF machines by heat treatments demonstrates the potential for producing high-quality Aluminum F357 components.

958 - Atomistic Modeling of Thermal Barrier Coating System to Investigate Interfacial Strength
Tejesh Dube, Indiana University-Purdue University Indianapolis

This study investigates the interfacial strength at topcoat/bondcoat and bondcoat/substrate interface for thermal barrier coating (TBC) systems fabricated using spark plasma sintering technique. Two atomistic models are built. The first model is a conventional TBC system with 8YSZ topcoat, NiCoCrAlY bond coat and 718 nickel base superalloy substrate. The second model incorporates the addition of Ti3C2 MXene layer between the 8YSZ topcoat and NiCoCrAlY bond coat. The MXene layer is added to slow down the oxidation of the bondcoat. Density functional theory (DFT) and molecular dynamics (MD) tools are used to study the atomic interactions at the interfaces and subsequently calculate the interfacial strength in ground state and at elevated temperatures. The results show that the addition of the MXene layer improves the adhesion between the topcoat and bond coat thereby creating a robust TBC system.

Poster of Merit Award

959 - Microstructure and Mechanical Properties of 316L Stainless  Steel Micro Additive Manufactured Components
Michael Pires, Lehigh University

Over the previous two decades, microfabrication technologies have been developed due to the high demand for micro-sized components. Current additive manufacturing (AM) processes have already made adequate progress in producing small-scale components, but the fabrication of micro-sized components may introduce compromised results. A comparative study between additive (standard-AM) and micro-additive manufactured (micro-AM) 316L stainless steel components was conducted to examine the respective resulting microstructures and mechanical performance. Components were produced via selective laser melting (SLM), binder jetting (BJ), and digital light processing (DLP). Microstructural characterization was performed with optical (LOM) and scanning electron (SEM) microscopy techniques. X-ray diffraction (XRD), X-ray energy dispersive spectroscopy (XEDS), and electron backscatter diffraction (EBSD) were performed to identify and quantitatively measure microstructural phases, grain size, and texture. Uniaxial tensile and microhardness testing was performed at scale for all 316L stainless steel components. Surface roughness was measured to evaluate its contribution to mechanical properties at scale.



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