Wear behaviour of CrB₂ + 5 wt.% MoSi₂ composite against cemented tungsten carbide (WC-Co) under dry reciprocative sliding condition

In the present work, reciprocative sliding wear behaviour of CrB₂ + 5 wt.% MoSi₂ composite was studied against WC-Co ball using different normal loads (5, 10 and 20 N) and frequencies (10, 15 Hz) under dry condition. Coefficient of friction (COF) and wear rate were measured at all test conditions. Wear mechanism was analysed by micro-structural characterization. It was found that COF is decreased from 0.68 to 0.32 with increasing load (5 to 20 N) and reciprocating frequency (10 to 15 Hz). The wear rate measured was minimum at 10 N load and 15 Hz frequency combination and was found to be 1.06 × 10^-6 mm³/N m. The wear mechanisms identified during reciprocative sliding wear of CrB₂ + 5 wt.% MoSi₂ composite were abrasion, micro-fracture and surface tribo-oxidative reactions with delamination from tribo-zone. While abrasion with mild oxidative wear is the dominant wear mechanism at lower load (5 N) and frequency (10 Hz) combination, intensive tribo-oxidative wear was observed at higher loads (>10 N) and frequency (15 Hz).