Microstructure and properties of ultrafine-grained and dispersion-strengthened titanium materials for implants

Wear-resistant titanium materials with high hardness and strength can be manufactured by introducing very fine titanium silicides and carbides into an ultrafine-grained titanium matrix. Nanocrystalline titanium particles with fine and homogeneous distributed carbon and silicon were generated by high energy ball milling of titanium with silicon powder or additions of the organic fluid hexamethyldisilane (HMDS). Spark Plasma Sintering (SPS) was chosen to compact the granules to prevent grain coarsening during sintering. Additionally, the Ti5Si3 and TiCx dispersoids limited grain coarsening. After sintering, the novel materials exhibited high hardness and strength, and excellent wear resistance. The electrochemical behaviour (comparable to that of commercially pure titanium) was also tested and showed the excellent suitability as an implant material.