Micropatterns of W-Cu composites fabricated by metal powder injection molding

Abstract

The metal powder injection molding (MIM) process has been applied to fabricate micropatterns of W-Cu composites. A 150 mu m x 150 mu m x 300 mu m column array patterned lost plastic mold was used as the mold insert. Several parameters were examined to overcome limitations of lost plastic molding such as low plastic strength, unvented blind hole structure and parting line. Molding temperature was a more dominant factor than molding pressure for the complete filling of feedstock into the micro patterns. The intrinsic defects originating from the lost plastic mold could be eliminated by the re-injection molding of the disc-shaped green part in a vacuum. The final micropatterns of W-Cu composite were fabricated by sintering at 1100 degrees C and 1300 degrees C for 1 h.