Tribological behavior of Al2O3/Al composite coating on γ-TiAl at elevated temperature

An Al2O3/Al composite coating was fabricated on the γ-TiAl alloy substrate to improve its friction wear performance at elevated temperature. A series of ball-on-disk type tests, sliding against a Si3N4 counterpart, were carried out at three temperatures: 20, 300 and 500 °C. The wear rates and friction coefficients of Al2O3/Al composite coatings at elevated temperature were much less than those of substrates. The anti-wear behavior of Al2O3/Al composite coating is attributable synergistically to its high hardness, excellent elastic modulus and self-lubrication by Al2O3 particles. This coating may be potential surface enhancement for Ti–Al intermetallics at elevated temperature.