The hardening mechanism of tools in ultrasonic drilling — an investigation by an X-ray diffraction technique

The hardening mechanism of tools in ultrasonic drilling was investigated by studying the variation in the microhardness of the tools used and the X-ray diffraction patterns obtained. Various tool and work material combinations were used, and the extent of increase in microhardness of tool materials was analysed. In addition, the nature and extent of the residual stresses left on the surfaces of the tools used were investigated.