Modeling and verifying of sawing force in ultrasonic vibration assisted diamond wire sawing (UAWS) based on impact load

Ultrasonic vibration assisted diamond wire sawing (UAWS) is an effective sawing process for hard and brittle materials such as monocrystalline SiC and Si. Compared with the conventional diamond wire sawing (CWS), both of sawing force and workpiece surface quality are improved by UAWS greatly, but the principle of improvement is still unclear. In order to reveal the mechanism of sawing force reduction in UAWS, this paper presents a theoretical model for sawing force in UAWS based on the theory of impact load. Firstly, the transverse vibration model of the diamond wire saw in UAWS was established based on the transverse vibration theory of continual system. Secondly, the impact load model of single abrasive was established based on the vibration model. The validity of this impact load model was verified by the finite element simulation. Thirdly, the sawing force caused by multi abrasives was derived based on the distribution of abrasives on the surface of wire saw. Finally, the verification experiments were conducted on the monocrystalline Si workpiece in various groups of processing conditions. The average error between the experimental and theoretical results of sawing force is 7.50%, which verifies the validity of the theoretical model. The measured results also indicate that the workpiece surface roughness of UAWS are 4.3%-29.7% lower than that of CWS.