Porous titanium prepared by metal injection molding based on space-holder technique

Porous titanium was prepared by metal injection molding (MIM) and high vacuum sintering using polymethyl methacrylate (PMMA) particles as pore forming agent and polyformaldehyde (POM) as main binder. The effects of PMMA and sintering temperature on the pore characteristics of porous titanium were investigated in detail. The results showed that PMMA particles are melted and mixed with organic binder together and lose their original particle characteristics (particle size and shape) during kneading. In the process of thermal debinding, PMMA decompose before high-density polyethylene (HDPE) in the temperature range of 350～420 ℃, which play the role of pore formation, but the shape of pores was irregular and the pore sizes are much smaller than the original PMMA particle sizes. In the sintering temperature range of 1100～1250 ℃, the opening porosity and pore sizes of porous titanium decrease with increasing of sintering temperature. When the sintering temperature is 1150～1200 ℃, the opening porosity of porous titanium is 34%～35%, and the pore size is about 9.1 μm.