Wear study of CBN tools in laser ultrasonic composite cutting of cemented carbide

Abstract

The laser ultrasonic composite cutting (LUCC) process was proposed by combining laser heating-assisted cutting (LHAC) and elliptical ultrasonic vibration cutting (UVC). In the process of cutting experiment, cubic boron nitride (CBN) is selected as the tool’s material. The wear morphology and wear appearance of the tools were observed by super depth-of-field microscopy and scanning electron microscopy (SEM) to research the wear characteristics and wear mechanism of CBN tools during LUCC of cemented carbide. Compared with conventional cutting (CC), UVC and LHAC, during LUCC of cemented carbide with CBN tools the tool wear are significantly reduced by 45.11%, 28.92%, and 17.39% respectively, the cutting force are decreased by 61%, 44%, and 46% respectively, and the surface roughness are lowered by 77%, 55%, and 62% respectively, therefore the tool life is obviously lengthened. Moreover, the tool flank wears model of during LUCC of cemented carbide was established and verified by the tool flank face wear test. The results show that when the CBN tool is used for LUCC of cemented carbide, the wear band on the tool’s rake face is basically parallel to the cutting edge and is in the shape of a long strip, and the wear band on the tool’s flank face shows a triangular-shaped wear band accompanied by shallow pits and grooves; In the process of the LUCC of cemented carbide, the main causes of CBN tool wear include adhesive wear, oxidation wear and abrasive wear are the main causes of CBN tool wear during LUCC of cemented carbide; The faster the cutting speed, the bigger the error among the experimental value with the calculated value, and the wear of tool’s flank face during LUCC of cemented carbide gradually increased.