Nanomechanical and Tribological Properties of Hexagonal-Boron Nitride-Enhanced Sintered Titanium Alloy Matrix Composites

Abstract

This work explored the influence of varied content (1, 3 and 5 wt.%) of hexagonal boron nitride (h-BN) on the nanomechanical and tribological properties of Ti6Al4V matrix composites (TMCs) developed by spark plasma sintering (SPS). Scanning electron microscopy/energy-dispersive X-ray spectroscopy, optical microscopy and X-ray diffraction were employed to characterize the microstructural and phase constituents of the sintered TMCs. Also, nanoindentation and tribology experiment using an automated nanoindenter at maximum load of 200 mN and pin on disk tribometer under 5, 10 and 15 N applied loads were performed, respectively. The results obtained showed that SPS enabled accomplishment of well-refined grains, formation of highly densified product and development of solid matrix-reinforcement interfacial bond. It was also found that the TMCs exhibited continuing enhancement in nanoindentation hardness (50.66 ± 2.25-70.78 ± 3.34 GPa) and modulus of elasticity (238.69 ± 12.25-356.76 ± 21.34 GPa) values and improved tribological properties with increasing h-BN reinforcement content.