Effect of the addition of crystalline β-phase in Al–Cu–Fe quasicrystalline coatings on their tribological properties

We investigate tribological properties (friction coefficient, wear, and adhesion force with fretting tests) of both quasicrystalline (Ψ-phase) and dual-phase (Ψ + β-cubic phases) Al–Cu–Fe coatings produced by electron-beam physical vapour deposition. Performed standard pin-on-disk tests (using bear steel pin and a load of 2 N) indicate that both quasicrystalline and dual-phase (Ψ + β) Al–Cu–Fe coatings exhibit close values of the friction coefficient (≈ 0.2–0.3) in vacuum. At the same time, the wear rate of the dual-phase coating is found to be essentially lower than that of quasicrystalline coating. It is demonstrated also that the value of the adhesion between the coating and the steel counterpart under fretting depends on the coating structure. The lowest adhesion is found to be observed for quasicrystalline coatings. Possible origins of the tribological behaviour of the coatings and their potential applications are discussed.