Tribological Characterization of the Modified Cast Al-Si Eutectic Alloys

The focus of this investigation is on the modification of Fe-rich intermetallics morphology and wear and friction properties of eutectic Al-Si alloys. Eutectic Al-Si specimens were fabricated by tilt casting after addition of different amounts of iron and manganese to the molten alloy. Dry sliding tribological behavior of the samples was investigated using a reciprocating wear tester at room temperature in atmospheric environment. It is found that the addition of iron up to 1.5 wt % to the alloy decreases the wear resistance of the alloy owing to the formation of brittle plate-like interme-tallic compounds of -Al5FeSi. As Manganese is added to the -containing alloy up to the half of the iron content (corresponding to a Mn/Fe ratio of 0.5), the platelet phases are completely replaced by the star-like intermetallic -Al-15(Fe, Mn)(3)Si-2 resulting in improved wear resistance of the alloy. Introducing 0.8 wt.pct Mn to the alloy containing 1.6 wt % Fe did not convert the plate-like beta intermetallics to the modified alpha compounds completely and had no impressive impact on the wear rate of the alloy.