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

901 – Investigating the Relationship Between Resonance Signature and Material Density
Julie Hedlund, Pennsylvania State University, DuBois

Resonance Testing is used in the powder metal industry as a way of quickly checking parts for defects after being sintered. Each sintered part should have a standard resonance signature when going through testing according to density. Then if a part has a defect, the resonance signature will be off. Each defected parts signature should correlate according to the defect. If this proves true, then classifying parts according to the type of defect could save time and money. If parts can be classified according to resonance signature and type of defect, a database can then be created to recommend different solutions for mending the defect if applicable. The system could also send out a red flag notice if a certain number of parts are presenting with the same defect; saving scrap costs, material, and time. This reduces time spent in the laboratory finding the location of the defects and then time creating a solution for numerous parts that may have already presented with the defect.

910 – Role of Manganese Composition on the Strain-Controlled Fatigue Life in Additively Manufactured 316L Austenitic Stainless Steel
Ian Wietecha-Reiman, Pennsylvania State University, State College

Manganese compositions in additively manufactured 316L austenitic stainless steels typically fall in a range between 1 and 2 mass fraction (%).  When coupled with oxygen contents on the order of 0.1 mass fraction (%), the precipitation of spinel oxides during solidification is promoted.  Decreases in the manganese composition to a level on the order of 0.5 mass fraction (%) leads to the replacement of these spinel oxides with tridymite and Cr2N phases.  The emergence of these phases activates new fatigue failure mechanisms that vary with locations within the specimen and leads to a decrease in the strain-controlled fatigue life when process porosity is mitigated.  In the fine grain structures present within the contour passes at the specimen edges, intergranular failures are primarily initiated along austenite grain boundaries populated with micro- and nano-sized Cr2N and Mn-bearing spinel oxide phases.

913 – Characterizing Flowability of Water Atomized Powders for Laser Powder Bed Fusion Additive Manufacturing
Sarah Birchall, Carnegie Mellon University

This work focuses on the use of water atomized (WA) metal powders as an alternative to gas atomized (GA) powders in laser powder bed fusion (LPBF) additive manufacturing (AM). WA powders are a cost-effective option with a high yield of powders and high surface oxygen contents, however, GA powders are more spherically shaped making them more commonly used in LPBF AM. This project centers on three WA powders, SS316L, IN600 and IN740H, which were characterized using SEM imaging, a CNN pipeline, and rheological tests. Flow properties, such as flow angle, cohesion, shear flow, and dynamic flow, were analyzed using a powder rheometer and rotating drum technique. These properties, along with SEM images, were placed into a CNN pipeline to explore how qualitative factors affect flowability in LPBF AM. This talk will include the results of flow tests, images of powders, the CNN pipeline, and the analysis of these findings.

914 – Shell Designs for Tailoring Dissolution Rates of Selective Laser Sintered Pharmaceutical Printlets
Amrutha Dinesh, Texas A&M University

With the advent of personalized medicine, 'Just In Time' manufacturing of solid dosage pharmaceutical formulations is necessary The objective of this study is to investigate the behavior of shell-based designs, predominantly in their ability to affect dissolution rates of additively manufactured (AM) pharmaceutical pills/tablets (printlets). For this, Selective Laser Sintering (SLS) was used to manufacture tablets using a powder mixture consisting of Carbamazepine (CBZ) as the active ingredient (drug), Kollidon VA64 as the excipient (polymer), and gold sheen as the agent with high laser absorptivity. A design of experiments was implemented to investigate the influence of % drug fraction and geometrical differences (shell thickness) on the manufacturability and mechanical/pharmacokinetic performance of the printlets. Results show a general inverse relationship between structural integrity (as measured by pharmaceutical 'hardness' tests) and drug dissolution rates, as expected. FTIR and XRD analyses confirmed that there was no appreciable drug degradation. Altogether, this effort yielded a viable approach to 'tune' dissolution rates of certain solid dosage formulations.

915 – Control of Residual Stress and Distortion in Metal Additive Manufacturing via Inverse Mapping of Textures
Ruoqi Gao, Georgia Institute of Technology (Georgia Tech)

Part distortion has been the main barrier to making 3D metal AM a manufacturing success.  The distortion is largely attributed to residual stress, which is closely affected by microstructure and anisotropy that are driven by texture evolutions due to thermal energy deposition.  The distortion issue has been analyzed in many other studies purely by experimentation or numerical iterations per macroscopic part dimensioning while missing the critical consideration of microstructure attributes.  In these earlier approaches the thermo-mechanical structures and properties have been assumed isotropic and uniform which contradict the effects of high thermal gradients occurring in the 3D AM process.  This work develops a computational-mechanics texture-driven platform for the prediction and control of residual stress and part distortion in metal additive manufacturing (AM) via inverse mapping of microstructure in the fusion process parameter space. It has intentionally avoided experimental curve-fitting and finite element iterations for significant computational speed and accuracy gains. The proposed project will further link the AM process parameters to microstructure then to the final residual stress development and part distortion in explicit expression forms.

916 – Novel Manufacturing of Molybdenum Alloys
Victoria Himelstein, North Carolina State Univeristy (NCSU)

Currently, blades fabricated from investment cast nickel-based (Ni-base) alloys are stymied by the material’s upward limit of 1000C, constraining the combined cycle efficiency at 63%. To increase material temperatures further, refractory materials offer immense opportunities to develop novel designs in a bottom-up approach for cooled blades with the aim of increasing overall cycle efficiency by 3-7%. However, the means to process and manufacture refractory materials into complex airfoil geometries is largely non-existent. Advanced manufacturing (AM) processes offer a compelling solution to fill this gap. Furthermore, the room temperature friability of these materials presents significant challenges to AM processing. In an effort to control oxidation and cracking, this study investigates the processing of Mo and Mo alloys through high ambient temperature Electron Beam Powder Bed Fusion (EB-PBF) AM.

921 – Effects on Microstructure of High Entropy Alloys
Alex Davis, Pennsylvania State University, DuBois

High-entropy alloys (HEAs) are presently of great research interest in materials science and engineering. HEAs typically contain at least five elements with equimolar or near equimolar concentrations. HEAs differ from traditional alloys because of high-entropy effects, lattice distortion effects, kinetic delayed diffusion effects, and “cocktail” effects. HEAs have the potential to be used in many applications such as, high temperature materials, cryogenic materials, etc. The method traditionally used on industrial scales for preparing HEAs is the vacuum melting method. However, the development of HEAs has been hindered by microstructure defects caused by vacuum melting, shrinkage cavity, shrinkage porosity, and segregation. This Study investigates the potential of using powder metallurgy (PM) for producing HEAs. Conventional and spark plasma sintering (SPS) were used to produce HEA parts from two powders, AlCrCoFeNi, and AlCrCuFeNi. Conventional sintering was at 1150˚C for 3 hours. SPS was done at at 40 MPa for 5 min at 1150˚C. SPS parts showed better properties compared to conventional sintered parts.

923 – A Binning Approach to Multi-Material Additive Manufacturing Through Laser Powder Bed Fusion
Suyash Niraula, University of Louisville

Additive Manufacturing (AM) has transformed the production of intricate structures offering unprecedented design flexibility however, incorporating multiple material compositions into these complex structures using standard AM systems presents significant challenges. This research proposes an innovative concept for streamlining the process of producing multi-material components in a traditional Laser Powder Bed Fusion (L-PBF) machine through a metallic powder binning technique. This work introduces a novel approach that involves dividing the powder feedstock supply into discrete tracks of individual materials, which remain distinct and intact during the spreading process. This technique enables the creation of components with spatially graded material properties. The effectiveness of this technique is demonstrated, along with a quantification of interfacial strength for an example case combining 316 steel with Inconel 625 as fabricated using an EOS M290 L-PBF machine.

902 – Analytical Prediction of Texture of Multi-Phase Material in Laser Powder Bed Fusion
Wei Huang, Georgia Institute of Technology (Georgia Tech)

Laser powder bed fusion (LPBF) has been broadly employed in metal additive manufacturing to create geometrically complex parts, where heat transfer and its resulting temperature distribution significantly influence the parts' materials microstructure and the materials properties. In determining material properties, crystallographic orientations play one of the critical roles among all microstructure representations due to the influence on anisotropy, void growth, coalescence behaviors, etc. This paper first developed a physics-based analytical model to predict the multi-phase materials texture related to the 3D temperature distribution in LPBF, considering heat transfer boundary conditions, heat input using point-moving heat source solution, and heat loss due to heat conduction, convection, and radiation. The superposition principle was used to obtain temperature distribution based on linear heat input and linear heat loss solutions. Then, by utilizing temperature distribution, the texture grown on a substrate with random grain orientations was analytically acquired, taking into account the columnar-to-equiaxed transition (CET). The correlation between texture and process parameters has been effectively established using CET models and the second law of thermodynamics. Ti-6Al-4V was selected to demonstrate the capability of the analytical models in a multi-phase situation. With applied advanced thermal models, the accuracy of the texture prediction is evaluated based on the comparison to experimental data from literature and past analytical model results and shows higher accuracy achieved. In this work, there is no involvement of any finite element iterations. This study not only offers a quick and precise way of analyzing texture prediction in multi-phase mode for metallic materials but also lays the groundwork for future research on microstructure-affected or texture-affected materials' properties, both in academic and industrial settings. The accuracy and reliability of the results delivered through this approach make it a valuable tool for further research and development.

903 – Validation of AF9628 Blown-Powder Direct Energy Deposition Parameters Through In-Process Monitoring and Mechanical Testing
Emmaline Hutchison, Ohio State University

AF9628 is a low-carbon, low-alloy steel developed by the United States Air Force with applications including additively manufactured munitions. This study examines the mechanical performance of AF9628 specimens manufactured using Blown-Powder Direct Energy Deposition after the completion of a parameter optimization investigation. In-process monitoring, and analysis were used to further optimize the process-parameter window. The chosen as-printed and heat-treated parameters were then validated through a combination of geometry builds, micro-hardness mapping, tensile testing, and charpy-impact testing, density measurements, and metallographic analysis.

904 – Strength, Microstructural Effects, and Stress Concentration Sensitivity in Green Metal Powder Compacts
Joseph Wright, Drexel University

Green metal powder compacts undergo fracture differently than their wrought counterparts due to the bonded particulate nature. While wrought components may exhibit fracture in an easily predictable manner, compacted powders may break at many particulate contacts and develop dynamic stress concentrations. Recent work has been done to understand powder compacts and their fracture behavior using side pressing of compacts with and without a hole.   The ratio of the two strengths provides insight for the microstructure length scale related to distributed internal defects and related to the powder distribution.  The ratio of the strength and the value of the strength of the specimen without a hole provides an estimate of the fracture toughness of the material. A review of the theoretical framework will be presented and experimental results related to FLNC-4408 (Ancorsteel 85HP + 2wt% Ni + 1.5wt% Cu + graphite) are presented and discussed.

905 – Scan Strategies and Texture Formation in Laser-Wire Directed Energy Deposition
Matthew Engquist, California State University, Los Angeles (Cal State LA)

Laser-Wire Directed Energy Deposition (LW-DED) is a novel technique that allows the production of large-scale metallic components with a relatively high deposition rate. The high cooling rates experienced in additive manufacturing processes create unique microstructures typically not seen in traditional manufacturing methods. Since the local solidification conditions are in part a result of the processing parameters selected, it follows that changing the printing parameters, in particular scan strategies, can lead to a change in microstructure and mechanical properties. In this study, the Meltio M450 LW-DED printer is used to prepare 316L samples with a variety of scan strategies by controlling attributes such as interpass delay and scan rotations. The resulting texture is evaluated with Electron Backscattered Diffraction and implications are discussed.

908 – Processing of NbTiZrTaV For Enhanced Mechanical Response
Nick Krienke, Colorado School of Mines

Refractory high entropy alloys (RHEAs) have gained attention due to their high temperature strength and phase stability. However, RHEAs often have ductile-brittle transition below room temperature making them less suitable for applications where toughness is needed. Recently, it has been seen that by introducing small amounts of oxygen, usually less than 3at%, both strength and ductility can be improved. The addition of oxygen creates ordered oxygen complexes (OOC’s) which enhances ductility through dislocation multiplication. Here, NbTiZrTaV was produced with powder metallurgy techniques to include various amounts of oxygen, and densified through either high pressure torsion or spark plasma sintering.  The resulting microstructures and mechanical properties will be reported with the goal of exploring the effect of oxygen content on hardness, yield strength, and plasticity.

909 – Graphene Impact on the Mechanical and Functional Properties of Composite Extruded Modeling Cordierite
Alvaro Garcia, University of Castilla-La Mancha

Graphene has shown substantial potential as a reinforcing material in ceramic composites due to its toughness, electrical conductivity, and potential modification of cordierite's resistance to thermal shock. Achieving optimal deagglomeration of platelets within the composite is crucial for maximizing its effectiveness. Composite extrusion modeling (CEM) emerges as a promising technique for fabricating graphene-reinforced cordierites with intricate geometries, particularly as a complement to ceramic injection molding (CIM). The incorporation of graphene into the binder system involved during processing facilitates nanoplatelet dispersion, leveraging intense shear forces during mixing. This study explores two methods of dispersing reduced graphene oxide. Moreover, the effect of different reinforcement loads on the mechanical and functional properties was examined. While much research has been focused on the study of nanoparticle dispersion in a matrix, this work succeeds in doing so in an industrially viable way by developing a scalable fabrication process to apply advances in specific aeronautic applications.

911 – Densification and Microstructural Evolution of Binder Jet Printed and Sintered Porous Ni-Mn-Ga Magnetic Shape-Memory Alloys
Pierangeli Rodriguez De Vecchis, University of Pittsburgh

Binder Jet 3D Printing (BJP) of polycrystalline magnetic shape-memory alloys (MSMAs) allow creating complex geometries from pre-alloyed powders. Porous and large-grained microstructures can help increase functionality of polycrystalline MSMAs by decreasing internal constraints to twin boundary motion. This study focuses on the microstructural evolution of BJPed porous Ni-Mn-Ga during isothermal sintering to determine the densification mechanisms taking place over temperature (1070, 1080 and 1090 °C) and time (0-8 h) to tailor the microstructure. Stereology was used to determine the grain and pore size, and sintering mechanisms as defined by Coble’s model for intermediate stage sintering. Sintering at 1070 °C resulted in an interplay of densifying and coarsening mechanisms, while at 1080 °C the dominating mechanism was volume diffusion and at 1090 °C grain boundary diffusion.

912 – A Novel Approach to Printing Soft Magnetic Composites
Hope Spuck, Pennsylvania State University, DuBois

As the electrification of our world continues to grow, the world will begin to look to the application of electric motors; but they will also look for ways to make the motors in a more efficient way. Soft Magnetic Composites (SMC) bring efficiencies in performance, size and design flexibility to electric motors; however, the processing of these components can be challenging. The current method with  heated compaction, very green densities, and long lubricant removal times makes the process very costly and challenging especially for larger components. 
In this work, we look at the application of a novel approach to producing SMC's. In previous work, it was demonstrated that typical water-atomized, add-mixed FC-0208 powder can be printed and sintered to 7.56g/cc without the need for a lubricant. Using similar technology, we will investigate the 3D printing of SMC's and consider a new processing approach to improve the processing efficiencies, increase design flexibility, and enhance the properties of the SMC's, while using commercially available powders.

917 – Implementation of Solidification Modeling Towards Tailorable Refractory Microstructures in Additive Manufacturing
Megan Le Corre, Colorado School of Mines

Additive manufacturing (AM) of traditional refractory alloys and refractory multi-principal element alloys (RMPEAs) promises to circumvent potential fabrication challenges associated with traditional manufacturing processes. While recent studies of refractory alloys produced by AM have revealed promising results, more work remains to evaluate the foundational solidification behavior associated with and responsible for the resulting microstructures and properties. Thermocalc (i.e., CALPHAD) modeling was first implemented to determine relevant thermodynamic parameters. Thermal gradients and solidification velocities produced by laser single track melts of refractory alloys were determined using heat transfer modeling. Microstructural morphologies are then correlated to predicted ones using the Ivantsov Marginal Stability model and Hunt modification to the Gaümann columnar to equiaxed transition model. Agreement or discrepancy between microstructural predictions and experimentally observed microstructures can be used to calibrate solidification models, ultimately enabling tailorable microstructures and properties in additively manufactured refractory alloys.

919 – A Comparative Study on the Tensile Deformation Behavior of Inconel 718 Fabricated via  L-PBF, LP-DED, and AW-DED: From Cryogenic to Elevated Temperatures
Alireza Bidar, Auburn University

This study compared the tensile behavior of laser powder bed fused (L-PBF), laser powder directed energy deposited (LP-DED), and arc wire directed energy deposited (AW-DED) Inconel 718 over a wide range of temperatures (from -195°C to 870°C). For all above-mentioned additive manufacturing processes, the tensile strength gradually decreased from -195°C to 650°C, and sharply declined from 650°C to 870°C. The tensile strength of L-PBF specimens was higher than that of LP-DED and AW-DED ones at all tested temperatures except 870°C, which could be ascribed to its smaller grain size. The ductility was similar among all three AM processes from -195°C to 425°C. At 650°C, L-PBF specimens showed slightly higher ductility than their LP-DED and AW-DED counterparts. At 870°C, while L-PBF and LP-DED specimens exhibited comparable ductility, AW-DED specimens showed notably higher ductility compared to L-PBF and LP-DED ones.

922 – Microstructures and Properties of AlCrCoFeNi High Entropy Alloy Cladded on F-0008 by Spark Plasma Sintering
Zakk Walters, Pennsylvania State University, DuBois

High-entropy alloys (HEAs) are presently of great research interest in materials science and engineering. HEAs typically contain at least five elements with equimolar or near equimolar concentrations. Because of their high-entropy effects, HEAs have the potential to be used in many applications such as high temperature materials, cryogenic materials, wear resistance, diffusion barriers, etc. They are traditionally fabricated by vacuum melting method. However, this method produces microstructure defects such as shrinkage cavity, porosity, and segregation. In this study, spark plasma sintering (SPS) was used for diffusion bonding (cladding) of AlCrCoFeNi onto iron core (F-0008) for surface modification and corrosion resistance. SPS was carried out at 50 MPa and 1150˚C for 5 min. Results on interface characterization, corrosion behavior, and mechanical properties are presented.

924 – Multi-Material Fabrication and Part Repair With Powder Direct Energy Deposition Additive Manufacturing
Justin Gillham, University of Louisville

The Additive Manufacturing Institute of Science and Technology (AMIST) at the University of Louisville recently acquired a BeAM Modulo 400 direct energy deposition (DED) metal additive manufacturing machine.  The Modulo 400 uses metal powder as its feedstock and runs as a 5-axis CNC mill with a deposition head in place of the spindle.  There are various use cases that are better suited to this technology rather than traditional metal additive manufacturing methods like laser powder bed fusion (LPBF) or metal filled filament fused deposition modelling.  A use of powder DED that has been investigated is multi-material fabrication and part repair.  In this study, the DED system is used to build upon existing geometries and add material to broken parts.  The Modulo 400 uses 316L stainless steel powder to build upon pre-fabricated LPBF parts and mechanical testing specimens.  The test specimens are then used to test the bond quality between materials.

927 – Investigation of Residual Stresses in Laser Powder Bed Fusion Manufactured Ti64 Specimens after Machining using X-ray Diffraction
Cristian Banuelos, University of Texas at El Paso

This study focuses on the characterization and analysis of residual stresses in Titanium alloy Ti64 samples produced via Laser Powder Bed Fusion (LPBF) technology and subsequently machined. Residual stresses play a critical role in determining the mechanical performance and dimensional stability of additively manufactured components. Understanding and mitigating these stresses is imperative for ensuring the reliability and structural integrity of parts in aerospace and biomedical applications. A series of Ti64 specimens were manufactured using LPBF, followed by precision machining to simulate post-processing conditions commonly encountered in aerospace components. X-ray Diffraction (XRD) was employed to assess the distribution and magnitude of residual stresses induced during the machining process. The study utilized non-destructive techniques to evaluate the depth and spatial variations of the residual stress fields.

928 – Exploring the Effect of Different Scanning Strategies on the Microstructure in IN718 Fabrication via Electron Beam Powder Bed Fusion
Shadman Tahsin Nabil, University of Texas at El Paso

Additive Manufacturing (AM) of metals is gaining popularity in the aerospace and defense sectors due to its ability to reduce weight and make unique parts. One significant challenge in the metal AM process is anisotropy, which refers to the variation in material properties in different directions. Sometimes this can require extra post-processing techniques like Hot Isostatic Pressing (HIP) or Heat Treatments (HT) to fix. This research aims to minimize anisotropy in the popular Ni-based superalloy IN718 during the Electron Beam Powder Bed Fusion fabrication process itself by implementing specific scanning strategies during the melt step of the metal. The results suggest the possibility of different scanning strategies to influence the microstructure, enhancing control over the transition from columnar to equiaxed structures in the build direction.

931 – A Study on the Influence of Process Parameters on the Microstructure and Mechanical Properties of LPBF Manufactured Ti-6Al-4V Components
Runlin Pu, University of Utah

This research focuses on Laser Powder Bed Fusion (LPBF), an advanced manufacturing technique for producing Ti-6Al-4V components with complex geometries, leveraging the alloy's notable strength and lightweight characteristics. It explores the critical influence of LPBF parameters—laser power, scan speed, and thermal cycles—on the microstructure of Ti-6Al-4V parts, which directly affects their mechanical properties. The study examines the effects of part orientation, surface strategies (including down-skin and up-skin), and geometric intricacies on the microstructure at specific locations, underscoring the necessity of microstructural understanding to predict component performance accurately. By characterizing the microstructure of a Ti-6Al-4V impeller produced via LPBF, the research demonstrates how layer-by-layer heating impacts microstructural characteristics. It further investigates heat treatment's role in altering the microstructure of LPBF-produced Ti-6Al-4V, aiming to refine manufacturing processes for improved material performance.

933 – Numerical Modeling of Laser-Wire Directed Energy Deposition Process
Nathan Stoetzel, California State University, Los Angeles (Cal State LA)

Directed Energy Deposition (DED) is an Additive Manufacturing (AM) method that has opened new possibilities for metal additive manufacturing due to its emergence in recent years. Laser-Wire DED uses high powered lasers to deposit a wire feed material onto a substrate in a prescribed pattern. Numerical modeling of this process is a valuable tool which can be used to predict the effects of various process parameters, reducing the burden on experimental testing. In this study, single bead samples of stainless steel 316L alloy produced by this process are analyzed and a numerical model is developed to simulate how process parameters affect the melt pool geometry and deposition behavior. The numerical model is developed in the computational fluid dynamics (CFD) software, Flow-3D. The model replicates a co-axial wire feed with six off-axis lasers focused to a single point, akin to Meltio M450 laser wire DED system. The simulation results are validated against the the experimental measurements within a reasonable level of accuracy. This model can then be applied to samples with more complex geometry, creating a valuable tool for predicting the outcomes of this process.

935 – Investigation of Microstructural Alignment Utilizing Engineered Cooling during Additive Manufacturing of Powder-Based Alnico Magnets
Luke Gaydos, Iowa State University

Alnico is an anisotropic, rare-earth free, permanent magnet (PM) which maintains its saturation magnetization while at temperatures up to 550oC but lacks the coercivity and energy product needed for a wide range of demanding applications. With an optimal set of processing and manufacturing techniques, alnico could replace Dy-free Nd-Fe B magnets in certain applications if the microstructure is textured in a 〈001〉 direction. Additive manufacturing (AM) of near-net-shape magnets may provide such texture. To investigate the possibility, directed-energy deposition (DED) in conjunction with an actively cooled substrate was used to build samples with a compositionally modified, gas-atomized, alnico 8 alloy. The resulting samples were solutionized and quenched, followed by magnetic annealing and a heat treatment. Magnetic properties and microstructures are compared to previous work. Funded by KCNSC through Ames Lab contract no. DE-AC02-07CH11358. Honeywell Federal Manufacturing & Technologies, LLC operates the KCNSC for USDOE/NNSA under contract number DE-NA0002839

936 – Extrusion-Based Metal Additive Manufacturing of 316L Using Highly Loaded Feedstock
John Reidy, Northwestern University

Powders with high tap density are of interest in extrusion-based metal additive manufacturing (AM) for their potential to produce highly loaded feedstocks. This paper reports the results of a high tap density 316L powder compounded into a feedstock at a loading of 70 vol.% and subsequently printed by bound metal deposition (BMD) on the Desktop Metal Studio System. The critical solids loading of the powder was determined by dynamic viscosity measurements at a range of solids loadings. Sintering of printed parts achieved densities of ~99%, at just ~11% shrinkage. Mechanical properties measured on the sintered samples were compared to values reported by MPIF Standard 35 for typical 316L produced by metal injection molding (MIM). The work presented shows the capability of high volume loading feedstocks in extrusion-based AM to reduce shrinkage compared with typical feedstocks, without deleterious effects to mechanical properties.

937 – Optimizing Surface Quality in Powder Bed Fusion of 316SS: Remedial Role of Shot Peening
Sivasubramanian Chandramouli, Purdue University

With the growing adoption of additive manufacturing (AM), especially laser-powder-bed-fusion (LPBF), in automobile and aerospace industries, process optimization is necessary to comply with existing industry standards of surface and mechanical properties. LPBF, as a layered manufacturing technique, surface roughness is a major issue that stems from powder characteristics with added influence of gravity in complex oriented parts. High surface roughness significantly affects product performance, especially fatigue properties due to the formation of stress-concentration points. The potential for enhancing surface topology and roughness solely through LPBF process parameter optimization is constrained, necessitating post-processing techniques. In this work, we investigated the effect of shot peening on roughness variations on LPBF-manufactured 316SS, considering surface orientations from 0-90°. Shot peening effectively reduced surface roughness by approximately 50% under optimized conditions, inducing a tensile to compressive residual stress transition. These results provide a pathway for improving the surface and component performance of AM parts through standardized industry post-processing surface modification techniques.

941 – Improved Design of a Customized Inkjet 3D Printer
Andrew Gillespie, Indiana University-Purdue University Indianapolis (IUPUI)

This study presents the construction and enhancement of an open-source binder-ink jet 3D printer called Plan B, designed by Ytech3d, despite the original designer's discontinued support and future upgrades in 2017. Our efforts focused on leveraging the open-source design to construct improvements for modernization, maintenance, operations, and printer safety for the user while keeping the cost and essential factors within the process. This paper outlines the technical improvements made to the printer while demonstrating how the open-source initiative can dive into future research and development within the powder-based additive manufacturing community while keeping it within a cost-effective range.

900 – FT4 Powder Rheometer Characterization of Interplanetary Regolith Simulants
Wesley Combs, Rice University

Leveraging extraterrestrial soil on the Moon and Mars is critical to the sustained success of future manned space travel and requires currently nonexistent material property information and engineering analysis. A collection of lunar and Martian regolith simulants were tested with an FT4 powder rheometer and its associated dynamic, bulk, and shear methodologies. These tests yielded Hausner ratios, flow resistances, compressibility percentaes, permeabilities, and yield loci. Mohr circle analysis was applied to collect cohesion, angles of internal friction, and flow functions. Additive manufacturing suitability was predicted using 1) Desktop Metal criteria and 2) the AMS factor, which was compared with printable Ti-6Al-4V. Hopper flow analysis according to Jenike stress theory was conducted for mass flow in conical and wedge shaped SS316 hoppers (average roughness of 1.2 micron). Lunar highland regolith simulant and Martian regolith simulant with high concentrations of polyhydrated sulfate provide the most in situ resource utilization advantages.

906 – Investigating the Potential of Laser Wire Directed Energy Deposition for Tailored Microstructures in 316L Stainless Steel Through Process Parameter Manipulation
Amirhesam Shakibizadeh, California State University, Los Angeles (Cal State LA)

Laser Wire Directed Energy Deposition (LW-DED) is a novel metal additive manufacturing process that, compared to powder-based processes, has lower cost and faster manufacturing time. The bead overlap, also known as hatch spacing, as well as the sample’s cross-sectional area, can have a significant role in the thermal behavior and evolution of the solidification microstructure during the process. This research studied the influence of processing parameters, including hatch spacing and sample geometry, on crystallographic texture formation during LW-DED. The samples made out of stainless steel 316L alloy were characterized using optical and scanning electron microscopy. The mechanical properties were also evaluated using micro-hardness and tensile testing. The crystal orientation and grain size were analyzed using Electron Back Scatter Diffraction. The findings can be used to enable tailored microstructure control in LW-DED products.

907 – Processing of WTaFeCr Multi-principal Element Alloys for Improved Mechanical Properties in Extreme Environments
Adam Freund, Colorado School of Mines

To reduce carbon emissions and improve eco-friendly power production, there has been a push for nuclear fusion technology. Fusion reactors, however, provide an extreme environment, with high operating temperatures and radioactivity. Tungsten is one proposed material for plasma-facing applications, but interactions between helium ash and tungsten cause rapid degradation. Recent advancements in refractory multi-principal element alloys (RMPEAs) have indicated potential use in this field due to their high temperature and phase stability as well as improved mechanical properties in extreme environments. In this work, WTaFeCr was produced through powder metallurgy techniques such as  mechanically alloying the constituent elements, densified through spark plasma sintering (SPS), and refined through high pressure torsion (HPT). The resulting microstructure and mechanical properties will be reported as an initial step towards understanding  the hardness, plasticity, yield strength, and radiation resistance of RMPEAs for use as potential plasma-facing materials.

918 – Effect of Carbon on Binder Jet Printed Ti64 Alloy
Barnali Sutradhar, University of Utah

Binder jet printing (BJP) emerges as a notable additive manufacturing (AM) technique that utilizes a binding agent to selectively bind layers of powder material. This process enables the creation of complex geometries with a wide range of materials. However, a significant challenge arises in the manufacturing of titanium alloys due to the presence of residual carbon after debinding, which might detrimentally impact the mechanical properties of the final sintered parts. Understanding the effect of carbon on Ti64 BJP parts is crucial for the advancement of this AM technology. This study investigates the impact of carbon on the properties of Ti64 BJP parts, with a particular focus on how processing factors—specifically, binder content or binder saturation—affect densification behaviors, phases, microstructures, and mechanical properties of sintered BJP Ti-6Al-4V alloys. It identifies optimal binder content and sintering parameters for fabricating BJP titanium parts.

920 – Tensile Behavior of Additively Manufactured Haynes 230 at Different Temperatures: A Comparative Study Between LP-DED and L-PBF
Rukesh Gusain, Auburn University

This study compared the tensile behavior of laser powder bed fused (L-PBF) and laser powder direct energy deposited (LP-DED) Haynes 230 from -196°C to 982°C. All specimens went through a multi-step heat treatment schedule consisting of stress relieving, hot-isostatic pressing, and solution annealing. The tensile behavior was correlated with the microstructure and fracture surfaces. Tensile strengths for both batches of specimens decreased with an increase in temperature due to reduced deformation twin density and grain boundary shear strength. At and below 649°C, the LP-DED specimens exhibited lower strength than L-PBF ones due to their larger grain size. From -196°C to 425°C, both batches of specimens had comparable ductility. However, at/above 649°C, there was a sudden increase in the ductility of LP-DED specimens. The fracture mechanism was governed by debonding of carbides at/below 649°C, and sliding between dynamically recrystallized grains above 649°C.

925 – Effects of Heating Rate on the Prior Austenite Grain Size of Free-Sintering and Low-Alloy (FSLA) Steels
Marcos Kendy Miyashima Moritugui, University of Pittsburgh

Selective Laser Melting (SLM) Additive Manufacturing (AM) involves the deposition of metal powder layer-by-layer, held together by welding the powder particles together. The dual-phased Free-Sintering Low-Alloy (FSLA) steel can have its microstructure tailored by post-printing heat treatments to produce a wider range of mechanical properties. Nano-to-micro-scale characterization (OM, SEM, EBSD, micro-indentation) and modeling techniques were employed to investigate the impact of different heating rates – ranging from conventional to ultra-fast – on the prior austenite grain size (PAGS) and on the microstructural homogeneity of FSLA-SLM alloys. These parameters have an important role on mechanical properties, which in turn will influence on particularly applications, such as the high-cycle-time fatigue in the automotive industry.

926 – Effect of Post-Processing Heat Treatment on the Stress Corrosion Cracking Behavior of Binder Jet Printed 17-4PH Stainless Steel
Borna Rafiei, University of Pittsburgh

It is well-established that stress corrosion cracking (SCC) susceptibility is strongly dependent on alloy microstructure. Additively manufactured (AM) materials exhibit unique microstructures relative to conventionally manufactured (CM) components, which could lead to differences in SCC performance. In this work, we investigate the effect of different post-processing heat treatments on the SCC behavior of 17-4PH fabricated via binder jet printing (BJP), which is a non-fusion AM approach. Electron microscopy-based evaluations confirm microstructural differences between CM and BJP 17-4PH, especially in the as-sintered condition, including porosity, retained ferrite/ austenite, and evidence of sensitization. SCC experiments are performed on each post-processing condition of BJP 17-4PH while fully immersed in quiescent 0.6 M NaCl and polarized to -1 VSCE. Results reveal a strong influence of post-processing on SCC as well as the fracture morphology. The causal factors potentially responsible for this variation are then discussed in the context of existing models for SCC.

929 – Effects of HIP Post-Processing on the Fatigue Life Behavior Under 4-Point (Flexural) Bending of Laser Powder Bed Fusion (L-PBF) Ti-6Al-4V
Diego Ariza, University of Texas at El Paso

The fatigue performance of Additive Manufacturing (AM) Ti-6Al-4V has been extensively studied under axial conditions; however, only a few studies have analyzed the fatigue behavior of this alloy under bending conditions. The presence of defects, such as gas porosity in powder, can detrimentally affect the fatigue performance of the samples by acting as stress concentrators. In the past, researchers have implemented the Hot Isostatic Pressure (HIP) post-processing method to minimize the presence of porosity and improve the mechanical properties of the samples. This project analyzes the fatigue life behavior of LPBF Ti-6Al-4V subjected to three different HIP treatments, including standard, low temperature/high pressure (LTHP), and super beta HIP during 4-point bending testing. Additionally, an annealed heat treatment was incorporated in the analysis. Preliminary results showed that the LTHP has a superior fatigue behavior across the HIP groups, suggesting that implementing specific HIP post-processing on AM samples can improve fatigue performance.

930 – Comparison Analysis of Heat Treated LPBF Ti-6Al-4V and Wrought Fabricated Titanium
Luis Marquez, University of Texas at El Paso

Additive manufacturing (AM) of Ti-6Al-4V alloy through the process of  LPBF allows the production of complex components not possible with conventional manufacturing processes. To advance further incorporation of this process into the aerospace, automotive, and biomedical industries, the material must meet mechanical requirements under dynamic loading defined by each sector. Therefore, this work presents an investigation of the effect of hot isostatic pressing (HIP) thermal treatments in the enhancement of fatigue performance of LPBF Ti-6A-l4V. The thermal treatments in this study were annealed, standard HIP, low-temperature + high-pressure HIP and super beta HIP. The fatigue experiments resulted in S-N curves defined by ten specimens for each heat treatment. The results are discussed in comparative analyses and showed super beta HIP having a superior fatigue endurance than standard HIP. In contrast, the annealed and low-temperature + high-pressure were outperformed. The discussion and analyses were supported by microstructural characterization and fractographs.

932 – The Effect of Build Orientation on the Fatigue Properties of LPBF Fabricated Ti-6Al-4V
Tristan Armstrong, University of Utah

Additive manufacturing, specifically laser powder bed fusion (LPBF), has emerged as a revolutionary technique for producing intricate structures with enhanced design flexibility in a time efficient manner. One of the big challenges facing this technology is the inferior fatigue properties present in LPBF fabricated components in the as-built state. Better understanding the factors that can influence fatigue performance in parts manufactured via LPBF is essential if this technology is to see wider use in critical engineering applications such as aerospace, automotive, and energy. Presented is a comprehensive analysis of fatigue test results conducted on specimens fabricated in various build orientations using LPBF. The focus of this work will be the influence of build orientation on the anisotropic microstructure of LPBF fabricated Ti-6Al-4V and how this impacts fatigue performance. The findings of this research contribute to advancing the knowledge of LPBF build design and guide the selection of optimal build orientations for Ti-6Al-4V components in critical engineering applications.

934 – Additively Manufactured 316L Stainless Steel with Copper Addition via Laser-Directed Energy Deposition (DED)
Michael Myers, Washington State University, Pullman

In response to the growing demand for advanced materials with tailored properties, this research investigates the material properties of 316L stainless steel with copper, as produced through laser-directed energy deposition (DED) additive manufacturing. The study focuses on three compositions: pure 316L, 316L with 3 wt% copper, and 316L with 5 wt% copper. Compressive loading and Vickers hardness tests were conducted to assess mechanical properties, while microstructural characterization and X-ray diffraction analysis provided insights into the material's phase and structural information. The research extends beyond material properties by exploring the on-contact antibacterial efficacy against Staphylococcus aureus, with timepoints at 24, 48, and 72 hours. The findings of this investigation have the potential to benefit sectors like aerospace and medical device manufacturing, contributing to both structural and bio-functional properties of materials.

938 – Automated Residual Stress Measurement for Laser Powder Bed Fusion
Navid Nasajpour Esfahani, Georgia Institute of Technology (Georgia Tech)

Various measurement techniques, such as splitting, hole drilling, deep hole drilling, slitting, x-ray diffraction, magnetic methods, and others, have been employed to determine residual stress in additive manufacturing. Furthermore, some researchers have utilized a combination of these techniques to validate their residual stress measurements. However, there is still a need for improvement in residual stress measurements, as many industries have begun digital manufacturing, integrating robots into their processes to expedite production lines. Consequently, there will be a future demand for automated residual stress measurement. In this research, the primary focus is on automating residual stress measurement in laser powder bed fusion. The interaction of various process parameters with X-ray diffraction will be discussed, and a dynamic approach will be provided for residual stress noise and outliers.

939 – Hot Isostatic Pressing of Additive Manufactured 316L Stainless Steel via Metal Binder Jetting and Metal Material Jetting
Michael Pires, Lehigh University

To date, a large deal of literature exists for hot isostatic pressing (HIP) of additive- and micro-additive manufactured (AM) components produced by laser-based technologies, but few exist for sinter-based AM (SBAM). As SBAM continues to grow in popularity in industry there exists a need to better understand the effects of HIP on their microstructure and mechanical properties. Altering temperatures (1000, 1150, & 1250 °C) and pressures (100, 140, & 207 MPa) were selected for HIP of 316L stainless steel. Components were printed via metal binder jetting (BJT) and metal material jetting (MJT) for a comparative study between existing AM and micro-AM processes in both their as sintered and HIP’d conditions. Scanning electron (SEM) and scanning transmission electron microscopy (STEM) were implemented to characterize the resulting microstructures following each processing condition. A combination of density, tensile properties, and Vicker’s microhardness was measured to determine the benefits of each HIP condition.

940 – Enhancing Strength in Binder-based 3D Printing of SS316L via Sub-micron Metal Material Jetting
Buhari Ibrahim, University of Michigan-Ann Arbor

Compared with other laser-based metals additive manufacturing (AM) processes, binder-based methods suffer from significantly lower strength due to coarse grain sizes. To address this issue, we employed novel metal material jetting (MMJ) of sub-micron powders to promote Hall-Petch strengthening in SS316L as representative material with industrial relevance. Overall, our results showed 55% and ~20 % improvement in yield and ultimate tensile strengths respectively compared to metal binder jet (MBJ) SS316L due to a 95% reduction in grains size. Insight on process-microstructure relationships for MMJ were further elucidated via a pressure-less sintering model validated using dilatometry experiments. These results showed a two orders of magnitude increase in sintering stress for MMJ compared to MBJ, leading to rapid densification and reduced grain growth. However, MMJ SS316L possessed a ~70% reduction in elongation compared to MBJ, highlighting significant need to improve strength-ductility synergy via tuning sintering process parameters.