The Effect of Heat Treatment on the Phase Composition and Tribological Behavior of Thermally Sprayed Al-Based Quasicrystalline Coatings

Al-Cu-Fe quasicrystalline coatings were prepared using detonation spraying, followed by heat treatment at 450 °C for varying durations. Reciprocating sliding wear tests were conducted using an MTF-5000 tribological tester to investigate the tribological behavior of the coatings with varying phase compositions and contents. The results show that heat treatment significantly influences the phase composition and tribological behavior of the quasicrystalline coating. Regarding the phase composition, as the heat treatment duration increased, the phase constitution of the coating evolved from the initial three phases to five phases. The content of the quasicrystalline I phase remained essentially constant with increasing heat treatment time, but exhibited a notable decrease at 241 h mark. For the friction coefficient, shorter heat treatment times resulted in a relatively low range (0.35–0.37), while excessively long heat treatment times led to a significant increase in the friction coefficient (0.44–0.48). Regarding the wear rate, it decreased approximately linearly with increasing heat treatment time, reaching a minimum value after 136 h of treatment. At this point, it is the optimal heat treatment time. In essence, heat treatment modifies the wear mechanism and wear resistance of the coating by altering its phase composition and mechanical properties.