Laser-dressing topography and quality of resin-bonded diamond grinding wheels
Laser-dressing topography and quality of resin-bonded diamond grinding wheels
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DOI：
10.1016/j.optlaseng.2020.106322
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发表时间：
2021
影响因子：
4.6
通讯作者：
H. Deng;Z. Xu
中科院分区：
文献类型：
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作者：
H. Deng;Z. Xu
激光修整技术在超硬磨料砂轮修整方面显示出极为突出的优势和广阔的应用前景。但该技术目前面临瓶颈，即砂轮表面变质层的生成机制尚不清楚，且未掌握热量积累效应对晶粒去除阈值的影响规律。本文系统地开展了单粒金刚石激光切割实验、树脂结合剂金刚石砂轮激光烧蚀实验和修整实验，并借助SEM、拉曼、EDS、XRD等检测手段，综合探讨了工艺参数对纳秒激光修整形貌和质量的影响。揭示了仿形过程中金刚石颗粒表面石墨层的生成和去除机制。首次发现石墨层与金刚石之间存在清晰的界面，且精加工时间的增加有利于降低异形金刚石晶粒的石墨化程度。首次阐明了刃磨过程中热积累效应对金刚石晶粒去除能阈值的影响规律。研究发现，随着光斑重叠率的增加，金刚石晶粒的去除能量阈值先降低后趋于稳定。创新性地探索了激光修整过程中树脂结合剂的热解过程和相变过程。结果发现，结合剂中C元素的比例增加，O元素的比例降低，而结合剂中辅助材料的成分和含量变化不大。最终完成激光修整参数的综合优化，实现树脂结合剂金刚石砂轮的低损伤、超精密修整。
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.