Fundamental Study on Friction Characteristics of EDMed Surface

摘要

The reduction in friction between machine elements is an important subject for machine design and manufacturing, and many studies on friction have been carried out so far. However, the control of friction characteristics is very difficult, since friction is an unstable phenomenon and is affected by many factors. This study aims to obtain fundamental data for controlling the friction characteristics of EDMed surfaces. First, by changing the shape and the arrangement of craters on the surface, the possibility of controlling the friction and wear characteristics was discussed. The effects of EDM conditions such as discharge duration and discharge current on the friction characteristics were experimentally investigated. As a result, it was pointed out that under low crater density, the coefficient of friction between a crater-arranged surface of an alloy tool steel and bearing steel ball became larger with an increase in crater density. It was clarified that the friction coefficient of an EDMed surface became smaller than those of ground surfaces and crater-arranged surfaces. Moreover, the friction coefficient of an EDMed surface increased with its surface roughness, as long as the resolidified layer remained on the surface.