Surface modification of highly porous titanium by plasma treatment

• For the first time, plasma was applied to samples prepared from MIM feedstock.
• The MIM feedstock contained titanium powders and a temporary space holder.
• Plasma treatment improved the stability and dimensional accuracy of the samples.
• Furthermore, the amount of open pores on sample surface increased significantly.
• Plasma treatment is a new method for supporting MIM processing of porous samples.

For titanium implants, a final porosity in the range of 60–65 vol% is required to achieve a network of interconnected macropores, which enables adequate fixation of the implant to the bone tissue and suitable mechanical properties. In addition, an open porosity at the implant surface is crucial for the success of the implant. In the present study, highly porous titanium foams were produced by warm compaction of MIM feedstock with the addition of space holder in a heatable die. Plasma treatment was performed on the Ti foams before the final sintering step aiming to increase the open pores at the surface. The results obtained so far demonstrate that plasma treatment is a promising technique for increasing open porosity at the surface. It even improved the dimensional accuracy of highly porous samples.