RELIEF-FACE FRICTION IN VIBRATION TAPPING

One of the key problems in the tapping process for difficult-to-cut ma terials such as titanium alloys is that the relief-face friction of th e tap is very large. In this paper, the vibration tapping process, in which the spring-back of the machined surface can be removed, has been analyzed with elasto-plasticity. Thus the reason why vibration tappin g can reduce the tapping torque has been explained qualitatively, and a theoretical basis for choosing reasonable values for the cutting par ameters for vibration tapping has been provided. The theoretical analy sis shows good agreement with the experimental results obtained when t apping a titanium alloy. (C) 1998 Elsevier Science Ltd. All rights res erved.