Study on wear and high-temperature oxidation properties of laser clad metallic silicide composite coatings on TiAl intermetallic alloy

γ-NiCrAl/Ti₅Si₃/TiSi composite coatings were fabricated on γ-TiAl intermetallic alloy by laser cladding with NiCr-Si precursor mixed powders. The room temperature wear resistance of the laser clad composite coatings was evaluated under dry sliding wear test conditions and the elevated-temperature isothermal oxidation-resistance was conducted at 1000°C for 50 h in air. The wear and oxidation mechanisms were discussed based on the experimental results. The results show that the sliding wear resistance of the laser clad composite coating increases. However, too high a volume fraction of the reinforcement phases leads to the decrease of wear resistance due to the brittleness of the composite coating. The isothermal elevated-temperature oxidation resistance of all the laser clad composite coatings is enhanced significantly and the relatively continuous oxide scales consist of α-Al₂O₃, TiO₂ and SiO₂.