Dry sliding wear of microalloyed Er-containing Al–10Sn–4Si–1Cu alloy

Abstract

With the rapid development of the machinery industry, bearing materials with better tribological properties are demanded. Al alloys containing Erbium (Er) and Zirconium (Zr) have better comprehensive performance, whose tribological properties have hardly been reported before. In this work, dry sliding wear tests were performed on the Al–Sn and Al–Sn–Er–Zr alloys in two different annealing states to study the effect of trace Er, Zr on the tribological properties of the Al–Sn alloys. The Al–Sn–Er–Zr alloys showed better wear resistance than the Al–Sn alloys, which was mainly due to the higher hardness and strength of the Al–Sn–Er–Zr alloys. The wear losses of the alloys annealed at 375 °C for 100 h at the load of 70 N were significantly lower than those of the alloys annealed at 300 °C for 4 h. The wear coefficient K of the alloys annealed at 375 °C for 100 h decreased with the increasing load. The Al–Sn–Er–Zr alloys showed smoother worn surfaces than the Al–Sn alloys. With the load increasing, the wear mechanism changed from abrasive wear, mild adhesive wear and slight delamination wear to severe adhesive wear and delamination wear. The wear scars of different samples under the same load were similar, indicating that the addition of trace Er, Zr and annealing process did not change the wear mechanism. All samples experienced cracks and voids in the tribolayers. And oxygen accumulated in these defects. Most wear debris were lamellar, which was related to the adhesive wear and consist with the delamination theory.