Laser dressing of arc-shaped resin-bonded diamond grinding wheels
Laser dressing of arc-shaped resin-bonded diamond grinding wheels
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DOI：
10.1016/j.jmatprotec.2020.116884
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发表时间：
2021-02-01
影响因子：
6.3
通讯作者：
Xu, Zhou
中科院分区：
文献类型：
--
作者：
Deng, Hui;Xu, Zhou
激光修整技术有望解决超硬磨料成形砂轮的修整问题。然而，该技术仍处于研究的初级阶段，并面临着诸如由于激光束的工具设置困难而导致的仿形精度差，由于激光聚焦特性而导致的锐化形貌不受控制，以及由于烧蚀热损伤而导致的晶粒性能降低等瓶颈。本文系统地进行了180 μ m左右弧形树脂结合剂金刚石砂轮的激光修锐研究。首次将声发射监测技术引入激光修锐，解决了激光束对刀精度低的问题。为实现圆弧砂轮的高效、精密仿形，对基于深切削和间歇进给的激光切向仿形方法进行了改进。将平行砂轮仿形为圆弧砂轮需要约4.5 h。受实验装置精度的限制，目前弧形砂轮仿形后的表面轮廓精度仅为20 μ m左右。发现砂轮表面中间区域的磨粒仅轻微石墨化，边缘区域磨粒的损伤程度较严重。提出了一种基于分层扫描的激光刃磨新方法，有效降低了激光扫描轨迹的控制难度，实现了砂轮表面各处结合剂的均匀去除和磨粒突起高度的精确控制。结果发现，激光束在锐化过程中不会损伤金刚石颗粒。与磨尖前相比，磨尖后树脂结合剂中C和0元素的比例分别增加约5. 7%和降低约5. 0%。
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.