Analysis and experimental verification of flow field in ultrasonic cavitation-assisted wire sawing

Diamond wire sawing plays an important role in semiconductor processing. Considering that the cavitation effect can improve the machining quality, a new technology of ultrasonic cavitation-assisted diamond wire sawing (UCAWS) is proposed in this paper. To study the formation process of cavitation in UCAWS and its influence on processing, a simulation and experimental study of cavitation in UCAWS is conducted. The pressure distribution model and cavitation model of two-phase mixed flow around wire sawing in UCAWS are constructed by combining the ideal bubble dynamic theory. The effect of vapor volume fraction (VVF) on cavitation intensity is calculated using computational fluid dynamics (CFD). The simulation results show that transient cavitation and steady-state cavitation exist simultaneously around wire sawing and with the increase of ultrasonic amplitude, the cavitation effect is enhanced. UCAWS experiments are conducted on monocrystalline silicon to study the changes in sawing force and workpiece surface roughness. The experimental results show that the sawing force of the UCAWS decreases by 6.65% on average compared to ultrasonic vibration-assisted diamond wire sawing (UAWS), the surface roughness value is reduced by 6.3% on average, and the surface morphology is improved. Therefore, UCAWS processing technology can be applied in manufacturing to improve the surface quality of the workpiece further.