The purpose of this research is to investigate the effect of heat treatment on the high-temperature wear characteristics of stir-cast AZ80 magnesium alloy. Dry sliding wear tests were performed on as-cast, T4, and T6 AZ80 using ASTM G99 - 17 at 25 °C, 150 °C, and 250 °C with a constant normal load of 10 N, a sliding speed of 1 m/s, and a sliding distance of 1000 m. Microstructures were analyzed with a Field-Emission Scanning Electron Microscope (FESEM) and an Electron Microprobe Analyzer (EMPA). X-ray diffraction (XRD) was used to examine the phases before and after the wear tests. In addition to α-Mg, the intermetallic phases Mg17Al12 and Mg2Al3 are also identified in AZ80. Compared to as-cast AZ80, T6 heat-treated alloy shows a maximum grain size of 72.64 ± 25 μm, with grain coarsening of 38.83 %. All test specimens, including T6 AZ80, exhibit indication of the Al-rich zone in the EPMA analysis, while T6 AZ80 shows evidence of the Mn-rich zone. Except for T4 AZ80 at 250 °C and T6 AZ80 at 150 °C and 250 °C, where the alloy experiences adhesive wear and oxidation, the abrasive wear and oxidation are common mechanisms observed in all test settings. At 150 °C, adhesive wear is responsible for 9.5 mg of the total wear in T6 AZ80. The alloy's wear behaviour is unaffected by presence of Zn. Intermetallic oxides (MgAl2O4) play a vital role in deciding the wear characteristics of the alloy.
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