Metal Injection Molding (MIM) is a manufacturing process that combines the principles of plastic injection molding and powdered metallurgy to produce complex- shaped metal parts. This process is particularly useful for creating small, intricate, and highprecision components that would be difficult or costly to produce using traditional methods such as machining or casting.
Feedstock Preparation:
Metal powders are combined with a polymer binder material to create a feedstock.
The metal powders used can include a variety of materials such as stainless steel,
titanium, cobalt-chromium, and other alloys.
Injection Molding:
The feedstock is heated to a semi-liquid state and injected into a mold cavity under
high pressure, much like the plastic injection molding process. The mold is typically
designed to create the desired shape of the final metal part.
Debinding:
The molded part, known as the green part, is then subjected to a debinding process
to remove the majority of the polymer binder. This is often done through thermal or
chemical means.
Sintering:
The debound part is then subjected to high temperatures in a controlled atmosphere
in a process called sintering. During sintering, the metal particles fuse together, and
the remaining binder material is completely removed. The result is a fully dense metal
part with the desired mechanical properties.
Finishing Operations:
After sintering, additional finishing operations such as machining, heat treatment, and
surface treatments may be performed to achieve the final specifications and surface
quality of the part.
Metal Injection Molding offers several advantages, including the ability to produce
complex geometries, tight tolerances, and high-density metal parts with excellent
mechanical properties. It is commonly used in industries such as automotive,
aerospace, medical, and electronics for the production of small, intricate components like gears, brackets, and surgical instruments.