考虑蒸发效应、等离子体屏蔽效应与脉冲间能量累积效应基础上, 建立脉冲激光烧蚀青铜金刚石砂轮传热物理模型, 应用模型对脉冲光纤激光修锐青铜和整形金刚石分别进行传热数值计算, 依据数值仿真结果, 开展脉冲光纤激光烧蚀青铜轮和青铜金刚石砂轮的实验。理论研究和实验研究表明: 相关条件下, 当激光功率密度小于2.10×108 W/cm2时, 只能对青铜金刚石砂轮修锐; 当激光功率密度大于2.10×108 W/cm2小于2.52×108 W/cm2时, 能对青铜金刚石砂轮实现整形和修锐的合二为一; 当激光功率密度大于2.52×108 W/cm2时, 能对青铜金刚石砂轮实现大深度修锐, 但影响磨粒突出结合剂的高度和磨削性能, 以上研究为脉冲激光烧蚀青铜金刚石砂轮研究提供理论指导与工艺优化, 同时实验结果与数值模拟结果一致, 也验证了传热模型的正确性。

A heat transfer model for pulse laser ablation of a bronze-bond diamond grinding wheel was built by considering the effects of evaporation, plasma shielding, and energy accumulation under the pulse interval. The model was applied for numerical simulation of the heat transfer characteristics in the pulse laser ablation of bronze and diamond. According to the results of numerical simulation, experiments were conducted for pulse laser ablation of a bronze wheel and bronze-bonded diamond grinding wheel. The theoretical analysis and experimental results showed that under the indicated conditions, the laser of 2.10×108 W/cm2 could only perform dressing on a bronze-bonded diamond grinding wheel; the laser of 2.10×108 W/cm2-2.52×108 W/cm2 merged the truing and dressing of the grinding wheel; and the laser of greater than 2.52×108 W/cm2 realized great-depth dressing but seriously affected the projection height of grits from the bond and their grinding performance. These researches provide theoretical guidance for optimizing the process parameters associated with laser ablation of a bronze-bonded diamond grinding wheel and the experimental data is in good agreement with the numerical solution to the model, thus verifying the correctness and feasibility of the heat transfer model.