Influence of Particle Content and Porosity on the Dry Sliding Wear Behaviour of Cast In-Situ Al(Ti)-Al₂O₃(TiO₂) Composites

Cast in-situ Al(Ti)-Al₂O₃(TiO₂) composites, synthesized by dispersing titanium dioxide (TiO₂) particles in molten aluminium, which reduces these particles, partially or fully, forming alumina (Al₂O₃) and releasing titanium to the matrix alloy, may provide materials for lightweight components in automobiles and aircrafts. Wear tests, conducted at different normal loads and at constant sliding velocity of 1.05 m/s using a pin-on-disc wear testing m/c, under dry sliding conditions, indicate that the cumulative volume loss and wear rate of in-situ composites are significantly lower than those observed in either the commercial aluminium or Al-Ti base alloys, under similar load and sliding conditions. At a given particle content, the wear rate increases with increasing porosity content presumably due to its combined effect on real area of contact as well as subsurface cracking. The wear rate of in-situ composites having relatively lower porosity decreases with increasing particle content, but, at relatively higher porosity, decreases a little or remains unchanged with increasing particle content.