The most basic conventional powder metallurgy process, press-and-sinter, uses pressure and heat to form precision metal parts and shapes. Powder is squeezed (at room temperature) automatically in a rigid precision die at up to 50 tons per square inch into an engineered shape like a gear. Think of 50 compact cars stacked vertically and you have the pressure it takes to press the powder automatically in a mechanical or hydraulic compacting press. After the mass of powder is squeezed into a shape and ejected from the press, it is fed slowly through a special high-temperature controlled atmosphere furnace to bond the particles together. They are metallurgically fused without melting, a phenomenon called “sintering”.
Other processes are also used to consolidate powders into finished shapes such as cold or hot isostatic pressing, direct powder rolling, forging, metal injection molding and gravity sintering. In contrast to other metal forming techniques, PM parts are shaped directly from powders while castings are formed from metal that must be melted, and wrought parts are shaped by deformation of hot or cold metal, or by machining. The latest powder metallurgy technology to enter the market is metal additive manufacturing (also known as metal 3D printing).
Powder Metallurgy Consolidation Process vs. Other Metal-Forming Processes
There are advantages of using powder metallurgy over other metal-forming processes; however, it's important to understand that there are various advantages to using one process over another. If you are seeking to manufacturing a new component, or to evaluate whether or not a current component can be redesigned using powder metallurgy, we urge you to find a fabricator to discuss the process as early as possible. Working with a PM component fabricator early in the design process can lead to added benefits.
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