Laser dressing of arc-shaped resin-bonded diamond grinding wheels

摘要

Laser dressing technology is expected to solve the dressing problem of superabrasive forming grinding wheels. However, this technology is still in the initial stage of research, and is facing bottlenecks such as poor profiling accuracy due to the difficulty of tool setting of laser beam, uncontrolled sharpening topography due to laser focus characteristics, and reduced grain performance due to ablation thermal damage. In this paper, the research on laser dressing of arc-shaped resin-bonded diamond grinding wheel with a grain size of about 180 mu m was systematically carried out. Acoustic emission monitoring technology was first introduced into laser dressing, which solved the problem of low accuracy of tool setting of laser beam. The laser tangential profiling method based on deep cutting and intermittent feeding was improved to achieve efficient and precise profiling of arc-shaped grinding wheels. It took about 4.5 h to profile a parallel grinding wheel into an arc-shaped grinding wheel. Limited by the accuracy of the experimental device, the surface contour accuracy of the arc-shaped grinding wheel after profiling was currently only about 20 mu m. It was found that the grains in the middle area of the surface of the grinding wheel were only slightly graphitized, and the damage degree of the grains in the edge area was more serious. A new method of laser sharpening based on layered scanning was proposed, which effectively reduced the difficulty of controlling the laser scanning trajectory, and achieved the uniform removal of the bond and the precise control of the grain protrusion height everywhere on the surface of the grinding wheel. It was found that the laser beam did not damage the diamond grains during the sharpening process. Compared with that before sharpening, the proportion of C and 0 elements in the resin bond after sharpening increased by about 5.7 % and decreased by about 5.0 %, respectively.