A novel binder and binder extraction
method for powder injection molding of
tungsten cemented carbide
method for powder injection molding of
tungsten cemented carbide
(State Key Laboratory for Powder Metallurgy,
Central South University, Changsha 410083, China)
Central South University, Changsha 410083, China)
Abstract: An improved wax-based multi-component binder and a new debinding method termed high-pressure condensed solvent extraction were developed for powder injection molding of tungsten cemented carbide. The results indicate that a critical powder loading of 65% (volume fraction) and an ideal rheological properties were obtained by the feedstock based on the binder. High debinding rate and specimens with high strength were obtained by the debinding method. Moreover, by making high temperature holding time adjustable, it makes the subsequent thermal degradation process more flexible to debinding atmosphere and carbon content of the as debinded specimens controllable. The transverse rupture strength, hardness and density of the as-sintered specimens made by an optimized PIM process are 2.48GPa, HRA90 and 14.72g/cm3, respectively. Good shape retention and about 0.02% dimension deviation were achieved.
Key words: powder injection molding; tungsten cemented carbide; binder; rheological property