Metal injection molding of nanostructured

Nanostructured W-Cu composite powder was fabricated by mechanical alloying. Compacts were then prepared from the powder in the as-milled conditions, a nd after a thermal reduction treatment, by metal injection molding using a multicomponent wax/polyethylene/stearic acid binder system. A debinding cyc le was identified which resulted in a high surface quality of the bionic pa rts, shape retention, and complete removal of the binder. An intermediate i sostatic repressing step increased the bionic density but did not contribut e significantly to densification during sintering. Densities >96% of theore tical were achieved in the injection molded compacts for both powder condit ions via liquid phase sintering, notwithstanding the low brown density afte r debinding. This high sinterability is attributed to grain growth of the W and a double rearrangement process in the powder due to its intrinsic nano structural characteristics.