アルミニウム鋳造材の摩擦特性に及ぼす偏析Siの効果

抄録

The present study describes effects of the surface finishing condition by cutting on tribological properties of aluminum cast alloy. The testing surface was finished with various cutting speed with large lake face angled mono crystalline diamond tool tip using a CNC machining center. It was found that the exposed Si particle frequently removed from the surface finished at at lower cutting speed using sharp tool tip. The tribological properties were evaluated with a 3 ball on disc type testing apparatus mated with a three chromium alloy steel (SUJ2) ball with flat contacting surface in lubricated condition. Results showed that the friction coefficient and the surface damage including wear loss decreased with the increase in the Si removal rate. To clarify effects of Si removal on the tribological properties, an aluminum alloy without Si particle was examined. As results, small dimple formed by Si removal act as entrapment of the wear debris and the friction coefficient decreased. Therefore, it was concluded that the surface finish using sharp diamond cutter at a low cutting speed was effective means to improve the tribological properties of aluminum cast alloy.