Overview

The potential of powder injection moulding (PIM) for cost effectively forming small, complex, precision parts is finding application in the markets of fire arms, business machines and printers, hand tools, aircraft, automotive, ordnance, medical and dental, cameras and controls. The process is finding acceptance on a part by part basis, and is expected to penetrate almost all market segments in competition with investment castings.

Powder injection moulding process is similar to plastic injection moulding, with the difference that the polymer is filled with dispersed metallic or ceramic powders. This technology permits production of stronger, more uniform and more complex P/M parts. The process has virtually unlimited possibilities of low cost, three-dimensional design features and the ability to handle very fine metal powders than enable sintering to high densities, conferring high ductility and strength to the finished parts. PIM becomes more attractive when compared with other manufacturing techniques for medium to high volume production of small parts. The process is economical when intricate three-dimensional details in the part need to be introduced. Pressure die casting can produce the same shapes and details as PIM, but not in comparable materials - low alloy steels, stainless steel, magnetic alloys, nickel alloys, tool steels, etc. Investment casting no doubt covers a wide range of alloys than are currently available for PIM, the latter is particularly useful for fine details such as blind holes, recesses, sharp edges and internal or external threads.

A general flow chart illustrating the steps of the PIM process is...