Study of metal injection molding of highly porous titanium by physical modeling and direct experiments

•Warm compaction is a suitable physical model for optimization of MIM of highly porous parts.•Physical modeling showed that titanium with porosity up to 65% can be successfully produced by MIM.•Binder use results in long manufacture time, porous struts, high shrinkage and shape distortion.•Application of MIM and atomized powder reduces the oxygen content, stiffness and strength.•Further optimization is needed for upscaling of porous implant production by the method described. The prospects of metal injection molding (MIM) technique for manufacturing of highly porous titanium parts was studied by physical modeling, based on feedstock warm compaction experiments. The space holder method and typical MIM binder were used in all cases of the study. The influence of the starting powder (dehydrided and atomized) in feedstock on resulting properties of porous titanium was investigated. The size of space holder particles and space holder amount were adjusted to obtain porosity and pore size desired for medical implants application. NaCl and KCl were studied and compared as prospective space holder materials. The porous samples were characterized regarding their microstructure, uptake of interstitial contents and mechanical properties. For comparison, same investigations have been conducted on samples, which were prepared by established space holder technology based on cold isostatic pressing (CIP) and sintering. Finally, first direct MIM experiments and attempts of feedstock optimization were carried out. The peculiarities and problems of metal injection molding of highly porous titanium have been discussed.