Influence of silicon (wt.%) and heat treatment on abrasive wear behaviour of cast Al-Si-Mg alloys

In present paper, the influence of silicon (wt.%) and precipitation hardening treatment of cast Al-(4-20%)Si-0.3%Mg alloy on two body abrasive wear behaviour has been reported. Alloys under investigation were prepared via foundry route. Cast alloys were subjected to the precipitation hardening treatment following a sequence of solutionizing, quenching and artificial aging. All the alloys were solutionized at 510 °C for 4 h followed by water quenching (30 °C) and aging hardening at 170 and 210 °C for 12 h. Abrasive wear tests were conducted against 100, 320 and 600 grade SiC polishing papers at 3 N contact load. It was observed that increase in silicon (wt.%) reduced the wear rate. Heat treatment of all the alloys under investigation improved the wear resistance. Precipitation hardening at 210 °C results in better wear resistance than the alloys hardened at 170 °C. Optical microstructure study of alloys in heat treated condition showed that dendrite structure is broken down after the heat treatment and spheroidization of eutectic silicon takes place. Scanning electron microscopy (SEM) of wear surfaces of was carried to analyze the mechanism of material removal under abrasive wear condition.