Porous titanium processed by powder injection moulding of titanium hydride and space holders

Biocompatibility, bone-like mechanical properties, and good bone-to-implant anchorage are current requirements for permanent implants. Porous titanium can satisfy these requirements provided that sufficient porosity, large enough pores and interconnections allowing bone ingrowth can reliably be obtained with controlled processes. In the present work, porous parts are processed from titanium hydride based feedstocks containing space holders. Two formulations have been developed: a feedstock with a polyethyleneglycol based binder and NaCl space holders, and a feedstock with a paraffin based binder and PMMA space holders. Depending on the sintering conditions, porosity levels between 30 and 60% and open porosity between 10 and 40% are obtained, with pore sizes in the range 50–500 μm. The microstructure, porosity and mechanical properties of porous titanium sintered at various temperatures have been characterised by scanning electron microscopy and compression tests.