Metal injection moulding of thin-walled titanium parts for medical applications

The metal injection moulding technique (MIM) is already established for serial production of complex, mostly stainless steel parts. However for other materials, especially for titanium parts, there is still the need for superior purity and enhanced surface quality. Facing the challenge of obtaining suitable medical titanium MIM parts, advances have been made at Fraunhofer IFAM over the last few years. Investigations show the effect of very fine powders and different surface finishes of the mould: with polished moulds a very low surface roughness of less than 0.8 m of the sintered part was obtainable. Chemical and mechanical properties of the sintered parts show the complexity of interactions between sintering conditions, purity, particle size and binder components. Additionally tests concerning feasibility of moulding high aspect ratios, wall-thicknesses of less than 200 m and special features like a fine internal thread and hexagon head set structures were performed as well.