Sliding Wear Performance Of In-Situ Spark Plasma Sintered Ti-Tibw Composite At Temperatures Up To 900 Degrees C

Although Ti-based composites find wide industrial applications, their tribological behaviour, especially at elevated and high temperatures, is not conclusively evaluated. In this work, a sliding wear performance of metal - ceramic composite of 50 wt%Ti-50 wt%TiBw, which were in-situ produced by spark plasma sintering, was studied. Microstructural examination and X-ray diffraction analysis identified presence of two phases, Ti and TiB, and confirmed the formation of stable TiB whiskers-like grains (TiBw) during reaction synthesis of Ti and TiB2. Ball-on-plate dry sliding wear tests were performed against a 10 mm alumina ball under 5 N normal load with the sliding speed and distance of 0.1 ms-1 and 1000 m, respectively. The tests were performed at RT and elevated temperatures of 300 degrees C, 500 degrees C, 700 degrees C, 800 degrees C and 900 degrees C. The worn surfaces were studied using scanning electron microscopy and 3D profilometry to understand the responsible wear mechanisms. Results have demonstrated significantly reduced wear rates of Ti-TiBw composite as compared to reference pure Ti across all temperatures. The formation and the protective role of tribo-oxide layers on the surface of Ti-TiBw composite during elevated temperature sliding is reported.