The influence of Pb on the friction and wear behavior of Al–Si–Pb alloys

The tribological behavior of hot-extruded Al–Si–Pb alloys have been investigated under dry sliding at various temperatures. It is seen that Al–Si–Pb alloys containing 20 and 25 wt.% lead have better characteristics of friction and wear than those in the base alloy without lead at room temperature. Under high applied loads, the stable wear rate with the lowest level of coefficient of friction is found to be controlled by the formation of a tribo-layer covering most of the worn surfaces. The tribo-layer consists of compounds including Al2O3, Pb4SiO6 and Fe2O3. A tribo-layer consisting of mixture of Pb4Al2(SiO3)7, SiO2, Al2O3 and Fe2O3 is also found to be formed on the worn surface of an (Al–Si–Cu)–15Pb alloy at 100 °C, but no tribo-layer was observed on the worn surface of this alloy at 200 °C.