Abstract
In order to study the effect of heating on the dewaxed specimens which were metal injection molded varying injection speed and pressure, the structure were observed by an acoustic microscope and a scattering electron microscope, and also the transverse rupture strength was investigated.
According to the acoustic images and back scattering electron images of metal injection molded specimens which were heated over the melting point of polymer and cooled down to room temperature, there were obviously differences between the structures of green and dewaxed specimens. The polymer, which existed around metal powders before melt, flowed into the powder-powder interfaces at over melting point, and then solidified at the powder-powder interfaces and connected the powders at room temperature. Transverse rupture strength of the specimens heated at near the melting point of polymer increased with an increase in heating temperature. The strength of specimen heated at 503K for 300s were approximately six times higher than that of the dewaxed specimens. The flash of specimens heated at over melting point of polymer and cooled down to room temperature was removed easier and the fracture surfaces were smoother than those of dewaxed specimens.
