Design of a defined grain distribution brazed diamond grinding wheel for ultrasonic assisted grinding and experimental verification

Abstract

Ultrasonic assisted grinding (UAG) is a promising manufacturing technology in processing hard and brittle materials, mostly due to its excellent machining performance. In UAG, improvements in grain trajectory interactions and overlapping stemming from kinematic characteristics were identified as the main reasons for reduced grinding forces and improved processing quality. However, in existing studies, the grinding wheels with disordered abrasive grain distributions and irregular grain protrusion heights were generally used. Consequently, it is difficult to control both the interactions between grain trajectories and overlapping. Aiming to solve this problem, a brazed diamond grinding wheel with defined grain distribution was proposed in this study. The grinding wheel matrix was designed using finite element analysis, while abrasive grain distribution was obtained by kinematic analysis of UAG. Finally, the grinding wheel was prepared using brazing technology and to verify its grinding performance, an electroplated grinding wheel with the identic matrix and abrasive grain size was prepared. Morphology analysis of both grinding wheels has shown that compared to the electroplated grinding wheel, the brazed one has both higher and more uniform grain protrusion height. In the next step, UAG and CG experiments were carried out using the brazed and electroplated grinding wheel. The effects of grain distribution and grinding parameters on the grinding force, force ratio, surface profile wave, and surface roughness were studied. The results have shown that in similar operating conditions the brazed grinding wheel produced smaller grinding force, force ratio, smoother ground surface, and lower surface roughness compared to the electroplated grinding wheel. Additionally, for both grinding wheels, the UAG reduced grinding force, force ratio, surface roughness, and profile wave height. However, it also caused a more extensive ultrasonic vibration effect on grinding compared to the electroplated grinding wheel; its reduction percentage in grinding force was larger, while surface roughness and average height difference for UAG were higher compared to CG.