What is MIM
The basic principle of operation is that the metal powders are mixed with a binder material, typically polymers and wax, to form a feedstock.
The feedstock is processed as conventional plastic injection moulding (PIM), where it is heated up to a temperature high enough to make it melt and flow.
The molten feedstock is injected into a mould cavity under pressure, where the lower-temperature mould causes the feedstock to cool and freeze into the cavity shape. The shaped ‘green’ component is then ejected and thermally treated to remove the binder material, forming a ‘brown’ component.
Sintering is then used to densify the component into full density. The main advantage of MIM is the use of plastic injection moulding principles to form components with properties not possible from plastics.