導電性セラミックス工具を用いた無潤滑角筒絞り加工

Abstract

The large quantity of lubricant waste has become a very serious environmental issue. To realize zero emission of lubricants, dry deep drawing is attractive, but it is very difficult to apply to metal sheets. As one of the most promising methods without lubricant, the use of ceramic tools was proposed because of their high tribological properties. However, the workability of ceramics in tool preparation is inferior to that of alloy tool steel. Therefore, the forming of complex shapes is difficult. We propose the use of electroconductive ceramics for the tool in this study. The electroconductive ceramics can be formed by electrical discharge machining (die-milling electric discharge, etc). Therefore, the shape of the press die can be easily molded. In the previous paper, 10,000 repetitions of dry cylindrical deep drawing were achieved with the electroconductive ceramic tool. In this study, deep drawing of a rectangle, which is a more complex shape, was examined. As a result, 10,000 repetitions of dry rectangular deep drawing were achieved. The surface roughness of a dry-deep-drawn cup was equal to or better than that of a non-dry (oil)-deep-drawn cup. Moreover, it was confirmed that a complex shape of the press die could be easily molded.