Highly Porous NiTi Components Produced by Metal Injection Moulding in Combination with the Space Holder Method

摘要

Porous NiTi is a promising material for bone implants due to its bone-like mechanical and pseudoelastic behaviour. The combination of the space holder method (SHM) with the metal injection moulding (MIM) process has a high potential for the near-net-shape production of porous NiTi components. The MIM process with pre-alloyed NiTi powder avoids the expensive and difficult thermomechanical working, the machining and high losses of the starting material. The SHM guarantees a well defined pore size distribution with total porosities up to 70%. In the present study, NaCl, saccharose and PMMA were investigated regarding their suitability as space holder materials. Different pore sizes and shapes in the range of 100-500 μm were achieved using these space holders. The shape memory effect is demonstrated by differential scanning calorimetry (DSC) and by mechanical compression tests. Defiances and the general applicability of the MIM process in combination with the SHM are discussed.