Introducing PM

A complex planetary carrier for a four-wheel drive torque transfer system. A helical gear and blades of stainless steel used in laparoscopic surgical scissors. A manifold weighing over 6.5 tons used on an offshore oil platform. A steel connecting rod used in V-8 engines.

What do these diverse parts have in common? All were manufactured using a process called powder metallurgy.

Powder metallurgy, or PM, is a process for forming metal parts by heating compacted metal powders to just below their melting points. Although the process has existed for more than 100 years, over the past quarter century it has become widely recognized as a superior way of producing high-quality parts for a variety of important applications. This success is due to the advantages the process offers over other metal forming technologies such as forging and metal casting, advantages in material utilization, shape complexity, near-net-shape dimensional control, among others. These, in turn, contribute to sustainability, making PM a recognized green technology.

In reality, PM comprises several different technologies for fabricating semi-dense and fully dense components. The conventional PM process, referred to as press-and-sinter, was used to produce the planetary carrier shown here. The surgical scissor parts were formed through the metal injection molding (MIM) process, the manifold was manufactured through hot isostatic pressing (HIP), while the connecting rod was produced using powder forging (PF).

Using many of these PM processing techniques, as well as other processes such as spray forming, roll compaction, rapid solidification, and others, components are also produced today from particulate materials other than metal powders. These include cermets, intermetallic compounds, metal matrix composites, nanostructured materials, high-speed steels, to name but a few.

Every day, in some way, PM touches your life. MPIF has produced a video that introduces you to this part-forming technology and to the incredible array of applications in which it can be found. Click here or on the image at left to view Part 1 of this video, then be sure to continue with the rest of the video in Part 2.