Study on wear of casting aluminium alloys

Abstract

In the first report, the wear characteristics of aluminium alloys against the same alloys and against carbon steel ware described. In the case of aluminium alloys against carbon steel, the wear loss of each of the materials is vrey small irrespective of the sliding speed and the contact pressure. When aluminium alloys excepting hyper-eutectic aluminium-silicon alloy are combiend against the same alloys, partial welding phenomena (scuffing) can easily occur on the frictional surface as the sliding speed is increased.In this report, frictional characteristics such as the frinctional coefficient, the surface appearance and the surface roughness. The results obtained from this experiment are summerized as under:1. It has been thought that there are not always definite relationships between the frictional coefficient and the wear. However, in this experiment it is made clear that there exist intimate corelations between the two. In the case of aluminium alloys against the same alloys, the frictional coefficient increases along with the increasing of wear loss, especially where scuffing occurs, the frictional coefficient as well as the wear loss show a rapid increase. However, in the case of hyper-eutectic aluminium-silicon alloys against the same alloys and of aluminium alloys against carbon steel, the frictional coefficient decreases in conformity with the deminution of wear loss as the sliding speed is increased.2. In the case of aluminium alloys excepting hyper-eutectic aluminium-silicon alloy against the same alloys, scuffing can easily occur under a high sliding speed and at high contact pressure, and surface roughness in creases. The hyper-eutectic aluminium alloys sach withhard spots coming about on the frictional surface thereon, does not generate scuffing, for the hard spots on the either alloy come into touch with each other. While in the case of aluminium alloys against carbon steel, not only the wear losse but also the frictional coefficient are very small since the frictional surface is protected by an oxidized layer.3. Though unstable at the initial stage of wear, the surface roughness may get to the constant value when wear reaches astationary stage, and the value may be controlled according to the experiment conditions.