Effect of individual and combined additions of Al-5Ti-B, Mn and Sn on sliding wear behavior of A356 alloy

The effect of grain refiner, Mn and Sn additions on the sliding wear behavior of A356 aluminum alloys was investigated. The microstructure and worn surfaces of the studied alloys were characterized by optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The experimental results indicate that the alloy refined by Al-5Ti-B alloy exhibits equiaxed α(Al) dendrites and performs better wear resistance compared with the alloy without the grain refiner. Moreover, the addition of Mn can change the β-Al5FeSi phase to α-Al(Mn, Fe)Si phase and reduce the possibility of crack formation, thus improving the wear resistance. Sn added to A356 aluminum alloy forms Mg2Sn precipitates after heat treatment. Therefore, the unrealizable precipitation hardening Mg2Si phase and the softening β-Sn phase can reduce the hardness of the alloy, and finally reduce the wear resistance.