Dry sliding wear resistance characterization of titanium matrix composites reinforced with titanium carbonitrides

Abstract

Pure Ti and Ti-6Al-4V alloy show high specific strength, excellent fatigue strength and good corrosion resistance; however, their poor wear resistance limits potentially wider application. To improve the wear resistance of pure Ti and Ti-6Al-4V alloy, they were reinforced with two types of titanium carbonitrides (TiC1-xNx), TiC0.3N0.7 (N rich) and TiC0.7N0.3 (C rich). The composites with 2.5, 5.0, 7.5 and 10.0 vol.% reinforcement were fabricated by spark plasma sintering (SPS). Dry wear tests of the composites were performed against a 10 mm-diameter high-carbon-chromium steel ball under 23 N normal load, at a sliding speed of 100 mm/s and a sliding distance of 500 m using a ball-on-disk configuration. The pure Ti and Ti-6Al-4V alloy matrix composites with TiC0.3N0.7 showed good wear resistance compared to the composites with TiC0.7N0.3. For the TiC0.3N0.7 reinforcement, the pure Ti matrix composite showed better wear resistance than the Ti-6Al-4V alloy matrix composite. The specific wear rate of the pure Ti matrix composite containing 10 vol.% TiC0.3N0.7 was almost zero. The amount of nitrogen diffused into the titanium matrix was higher than that of carbon diffused into the matrix. The Vickers hardnesses of the composites with TiC0.3N0.7 were higher than those of the composites with TiC0.7N0.3, due to the solid solution strengthening of the nitrogen in the Ti matrix. Therefore, the dry sliding wear characteristics of the titanium matrix composites depended on the amount of nitrogen diffused into the Ti matrix.

Keywords

• pure titanium
• ti-6al-4v alloy
• titanium carbonitrides (tic1-xnx)
• tic0.3n0.7
• tic0.7n0.3
• titanium matrix composites
• dry sliding wear resistance