Fabrication of Ti6Al4V-TiC composite by metal injection moulding for enhancement of mechanical and tribological properties of Ti6Al4V

摘要

In this study metal injection moulding (MIM) process was used as a fabrication method for Ti6Al4V-TiC composite samples. The better efficiency, lower cost, design flexibility and high surface finish quality are the main advantages of this method. Ti6Al4V and Ti6Al4V-10 Wt% TiC (TMC_p) tensile samples produced by MIM were tested at different temperatures of 25℃, 250℃ and 400℃. The tensile test results showed higher strength for the composite material compared to Ti6Al4V sample at all temperatures. The improvement in mechanical properties became more evident at high temperatures. Tribological properties of the Ti6Al4V and TMC samples were investigated by wear tests using a ball-on-flat contact geometry under different loads of 5N, 10N and 15N and single pass scratch tests under progressive load of 0.1 to 10 N. The TMCp samples exhibited the lowest wear rate under 5N normal load, which was 6.5 times lower than the wear rate of Ti6Al4V sample tested at the same loading conditions. TiC particles were the main contact area. However, at 10N and 15N load most of the TiC particles were fractured and consequently the wear rates of TMCp were considerably higher when compared to those of Ti6Al4V samples. Nevertheless, particle pull out was not observed on any tribological conditions. Therefore, MIM can be employed as an ex-situ method to produce a good particle-matrix interface.