Investigation into high-shear and low-pressure grinding heat using liquid-body-armor-like wheel: Theory and modeling

Abstract

High-shear and low-pressure grinding with the liquid-body-armor-like wheel has significant advantages, such as good machining quality, high adaptability, and low cost. It has a considerable potential for application in the field of precision machining. A theoretical analytical model was proposed to understand the heat dissipation mechanism and the distribution of the heat source in the high-shear and low-pressure grinding with liquid-body-armor-like wheel. Firstly, the convective heat transfer coefficient of the cutting film at the interface of the workpiece surface and wheel was solved through combining the fluid dynamic and the heat transfer. Then, a heat source model for the high-shear and low-pressure grinding was established. The temperature field under three different shapes (i.e. rectangular, triangular, and trapezoidal) of the heat source distribution were solved. Additionally, the effects of grinding velocity, workpiece feed rate, and normal grinding force on the shape of the heat source distribution were analyzed. Finally, the grinding temperature during the grinding process was measured using the thermocouple on the experimental platform to verify the model. The findings show the trapezoidal distribution of heat sources has the minimum error as compared with the rectangular and triangular heat source distribution. The theoretical analytical results and finite element simulation results agreed well with the measured temperature values. The average error of the analytical results was 5.5 %. The theoretical temperature increased with the grinding velocity and the normal grinding force. It decreased with the increase in the workpiece feed rate. The highest measured temperature was only 91.68 °C at the grinding velocity of 14 m/s in this work. The temperature was significantly lower than that of the conventional grinding. This study provides theoretical guidance for the thermal behaviors and heat generation mechanisms in high-shear and low-pressure grinding processes.