Metal Injection Molding (MIM) is a manufacturing process that combines the design flexibility of plastic injection molding with the strength and integrity of metal. After molding the “green” part, the process requires thermal treatment in an industrial furnace to remove binders and sinter the metal powder into a dense, solid component. Industrial furnaces are essential for the two key post-molding stages: debinding and sintering.
Role of Industrial Furnaces in Metal Injection Molding
Debinding:
- In the MIM process, the metal powder is mixed with binders to form a feedstock that can be molded like plastic. After the “green” part is molded, the binder needs to be removed in a process called debinding.
- The debinding process involves heating the part in a furnace to remove most or all of the binder without affecting the shape of the metal particles. Industrial furnaces provide the controlled temperature and atmosphere needed for binder removal while preventing oxidation or degradation of the metal powder.
Sintering:
- Once debinding is completed, the “brown” part, which is still porous and fragile, is sintered in the furnace. The sintering process heats the part to a temperature just below the melting point of the metal, allowing the powder particles to fuse together and form a solid, dense metal part.
- Sintering in an industrial furnace removes any remaining voids in the part, achieving near full density and giving it the required mechanical properties, such as strength, hardness, and conductivity.
