Laser-dressing topography and quality of resin-bonded diamond grinding wheels

Laser dressing technology has shown extremely outstanding advantages and broad application prospects in dressing of superabrasive grinding wheels. However, this technology is currently facing bottlenecks that the generation mechanism of the metamorphic layer on the surface of the grinding wheel is unclear, and the influence rule of the heat accumulation effect on the removal threshold of the grain is not mastered. In this paper, the laser cutting experiment of single diamond grain, and the laser ablation experiment and dressing experiment of resin-bonded diamond grinding wheels were systematically carried out, and the effects of process parameters on the topography and quality of nanosecond laser dressing were comprehensively explored by means of SEM, Raman, EDS, XRD and other detection methods. The mechanism of generation and removal of the graphite layer on the surface of diamond grains during profiling was revealed. It was found for the first time that there was a clear interface between the graphite layer and diamond, and the increase of the finishing time was beneficial to reduce the degree of graphitization of profiled diamond grains. The influence rule of the heat accumulation effect on the removal energy threshold of diamond grain during the sharpening process was first clarified. It was found that the removal energy threshold of diamond grain decreased first and then stabilized with the increase of the spot overlap ratio. The pyrolysis process and phase transformation of resin bond during laser dressing were innovatively explored. It was found that the proportion of C element increased and the proportion of O element decreased in the bond, while the composition and content of the auxiliary materials in the bond changed little. Finally, the comprehensive optimization of laser dressing parameters was completed, and low damage and ultra-precision dressing of resin-bonded diamond grinding wheels were achieved.