Surface structure of lapping discs improves the processing performance and self-sharpening ability of agglomerated diamond abrasives

Agglomerated diamond (AD) abrasives have been proven applicable in the machinability of polyurethane lapping discs. However, the processing performance, material removal behaviour, and self-sharpening mechanisms of AD abrasives on lapping discs with different surface structures remain unclear. Therefore, in this study, we designed different groove-structured lapping discs and combined them with AD abrasives to conduct lapping experiments on sapphire wafers to investigate the processing performance of groove-structured lapping discs on AD abrasives and reveal the material removal behaviour and dynamic self-sharpening mechanism of AD abrasives. The results show that the groove-structured lapping disc exerts a guiding and restraining effect on the AD abrasives, improving processing uniformity and reducing their wear rate. Additionally, the groove structure enhances the vortex effect of the lapping slurry, which further improves the self-sharpening ability and processing performance of the AD abrasives. The polyurethane disc with a cylindrical groove-2# structure and a size ratio 1:100 produced the best processing results. At a processing cycle of 30 min, the average particle size of AD abrasive was 26.2 μm, which minimized micro-fracture and resulted in a processing effect with an material removal rate (MRR) of 2.51 μm/min and surface roughness (Ra) of 10.42 nm. The AD abrasives remove the surface material of the workpiece through a combination of two-body sliding friction and three-body rolling friction within the groove-structured disc, achieving superior processing efficiency and quality. • The grooved structure lapping disc can slow down the micro-fracture process of AD abrasive. • Compared to the non-grooved disc, the MRR of the grooved structure disc increased by 30.82 % and the Ra decreased by 32.14 %. • The material removal behaviour of AD abrasives in grooved structure lapping disc is revealed. • The grooved structure lapping disc can enhance the dynamic self-sharpening ability of AD abrasives.