Tribological Behavior and Tribochemistry of Self-mated Ti₃SiC₂ in Ethanol

The tribological behavior of self-mated Ti₃SiC₂ in low viscosity fluids, that is, water and ethanol, is investigated. The results show that both water and ethanol effectively reduce the friction and wear of self-mated Ti₃SiC₂. The friction coefficient and total wear rates of Ti₃SiC₂ tribo-pair are 0.82 and 2.17 × 10⁻² mm³/N m under dry condition, 0.41 and 6.50 × 10⁻⁴ mm³/N m in water and 0.16 and 2.22 × 10⁻⁴ mm³/N m in ethanol. As sliding distance is prolonged from 0.5 to 22.9 km, the total wear rates of Ti₃SiC₂ in ethanol can be further reduced. Mechanical wear of Ti₃SiC₂ is partly inhibited in water and greatly inhibited in ethanol. Surface polishing of Ti₃SiC₂ pin and tribochemistry are the two distinct characteristics of self-mated Ti₃SiC₂ in ethanol. The surface film in ethanol is composed of TiO₂ and SiO. Tribo-products in ethanol, that is, silica gel and titanium dioxide, are found. Polycondensation of ethanol by the catalysis of TiO₂ and SiO_2−x gives birth to paraffins and olefins.