Solutionizing temperature and abrasive wear behaviour of cast Al–Si–Mg alloys

In the present paper, the influence of solutionizing temperature during artificial age hardening treatment (T6) of cast Al–(8, 12, 16%)Si–0.3%Mg on abrasive wear behaviour has been reported. Alloys were prepared by controlled melting and casting. Cast alloys were given artificial age hardening treatment having a sequence of solutionizing, quenching and artificial aging. All the alloys were solutionized at 450 °C, 480 °C, 510 °C, and 550 °C for 8 h followed by water quenching (30 °C) and aging hardening at 170 °C for 12 h. Abrasive wear tests were conducted against 320 grade SiC polishing papers at 5 N and 10 N normal loads. It was observed that the silicon content and solution temperature affected the wear resistance significantly. Increase in solution temperature improved the wear resistance. Hypereutectic alloy showed better wear resistance than the eutectic and hypoeutectic alloys under identical conditions. Optical microstructure study of alloys revealed that the increase in solutionizing temperature improved distribution of silicon grains. Scanning electron microscopy (SEM) of wear surface was carried out to analyze the wear mechanism.