The sintering process is done using small metallic particles, or metal powder. The powder is compressed into the desired shape. Then it is heated to temperatures above the melting point, thus causing the metal particles composing the powder to join together and create a single solid product. The advantages to sintering are low cost, controlled material properties, shape complexity, and high production rates.
There are several other advantages to the process such as eliminating material waste, precision dimensional tolerance, and the ability to make the parts with virtually any alloy including custom alloy formulations.
The two most popular processes for sintering are powder metallurgy (PM) and metal injection molding. PM uses dies to compress the powder into desired shape prior to sintering, forming pressure keeps the parts in their net shape until sintering.
MIM is similar to injection molding, but uses a powdered metal with a polymer binder injected into a mold cavity. The part is ejected from the mold cavity then sintered.