Copper injection molding using a thermoplastic binder based on paraffin wax

In this work the processing steps for producing copper parts by means of metal injection molding technique were investigated. Different feedstocks were prepared from gas atomized copper powder and a thermoplastic binder based on paraffin wax. The optimum formulation of 95 / 5 wt/wt (copper powder / binder) was selected from rheological investigation and then the suitable feedstock was injected successfully at low pressure. The molded specimens were debinded by solvent debinding followed by thermal debinding methods and were sintered under argon atmosphere. It was observed that injection molding of a feedstock containing 66% by volume of copper powder was possible at low pressure and the sintered parts were free from defects and dimensional shrinkage was nearly the same in three dimensions.