Ultra-high flow materials for Powder Injection Molding (PIM)powder injection molding (PIM)

PIM is a technique for manufacturing miniature high-precision metallic or ceramic components. In PIM, a metallic or ceramic powder is first blended with a binder, then injection molded, processed to remove binder components, and sintered.

PIM was developed in the U.S. during the 1970s as an advanced approach to powder metallurgy for manufacturing metal components; the technique combined conventional methods of powder metallurgy with injection-molding techniques for plastics. The traditional approach to powder metallurgy, known as press molding, involved inserting metal powders into molds and could only produce components with relatively simple shapes. In contrast, PIM fabricates metal components according to the same principles used in injection molding, allowing mass production of complex-shaped components.

A typical PIM process, here assuming the use of a metallic powder (MIM) as an example, proceeds as follows.


First, the metallic powder is blended with a binder (plastic + wax) to yield a uniform mixture, which is compounded into feed-stock pellets with good formability properties. These pellets are then molded by an injection-molding machine, just like typical plastics. The resulting molding parts are heated and treated with solvents, catalysts, and other agents to remove binders, then finally sintered in a furnace to yield high-precision metal components. The molding parts obtained immediately following injection molding contain some concentration of binder resins, but these components are eliminated by the binder-removal and sintering steps, ultimately producing metallic bodies with complicated three-dimensional shapes.