High-temperature tribological properties of friction stir processed Al-30Mg2Si composite

The multi-pass mode friction stir processing (FSP) was applied to Al-30%Mg2Si in-situ composite under optimised conditions. Also, the influence of the pass number increase was evaluated on microstructure and dry sliding wear behaviour of composite at room temperature (RT) and High temperature (HT, 200 & x1d52;C). The optimal RT wear test results were achieved in the three-pass processed (3P) sample.Furthermore, elevating the wear test temperature increased the wear rate and the ACOF of the as-cast composite, compared with RT condition. Nevertheless, covering the worn surface of the FSPed sample by fragmented and evenly distributed Mg2Si particles and improved hardness (specifically in 2P and 3P samples) prevented the severe mass loss in FSPed samples and enhanced the HT wear resistance of Al-30Mg(2)Si composite. The active wear mechanisms of the as-cast and FSPed composite were also studied at both RT and HT conditions.