Student Information   

II.  Powder Metallurgy

A.  What is Powder Metallurgy and Why is it Used?

PM refers to a range of manufacturing and metalforming practices that are used to produce net or near-net shape parts from mixtures of metal and alloy powders.  The primary commercial PM processes for the production of parts and components are pressing and sintering; direct powder consolidation by hot isostatic pressing; and the densification of a preform by forging.  A schematic of these commercial sub-processes under the umbrella "PM" is shown in Figure 1.  Each process is versatile, efficient, cost effective, and environmentally friendly.  For many PM parts, secondary operations are eliminated completely or reduced significantly, compared to conventional processes because PM results in close dimensional tolerances.  PM offers many advantages compared to other metal forming technologies; these include:

·        Intrinsic ability to produce a broad spectrum of alloy compositions, including composites, with unique properties.

·        Control over the size, shape, and location of porosity in the part.

·        Tailoring of microstructures to produce a range of physical and mechanical properties.

·        Production of moderate-to-high volume quantities.

·        Fabrication of a wide latitude of shapes.

·        Ability to optimize the complete process, from material selection through manufacturing, to properties of the finished product.

·        Elimination of scrap, since parts are essentially net shape.

·        Cost effectiveness over competitive metalworking/forming processes such as casting, forging, and machining.

Figure 1: The PM Process Schematic.  Source "Powder Metallurgy Design Solutions,"1999, MPIF.