Abstract
Some alloys of Al–Si–Cu–Mg system were made by the gravity casting to develop alloys with the good wear resistance in boundary lubrication. The effects of silicon and copper contents on the sliding properties of aluminum casting alloys were investigated by the endurance test and the load carrying capacity test in the radial thrust rubbing test method. As the results, lower coefficient of friction were obtained at the alloy compositions of 23 mass%Si and 3 or 6 mass%Cu by the endurance test. On the other hand, higher the load carrying capacity of 2.5 MPa was obtained at the alloy composition of 23 mass%Si, 6 mass%Cu, 1 mass%Mg and balance Al. That was about three times compared with ADC 14 used with wear resistance alloy. Furthermore, it was found that the silicon contents range from 23 mass% to 30 mass% shows constant dispersion of the primary silicon of fine particles having effects on wear-resisting. And in the Al–23 mass%Si–6 mass%Cu–1 mass%Mg alloy, the micro-regions among the primary silicon led to more effect on improvement of the load carrying capacity because of the formation of lubricants bases.
