激光在线修整青铜金刚石砂轮数值仿真与试验

为了研究声光调Q YAG脉冲激光在线修整青铜结合剂金刚石砂轮,采用数值仿真和试验相结合的方法,在考虑金刚石石墨化过程的基础上,通过有限元数值模拟的方法建立了3维单脉冲激光烧蚀金刚石磨粒的数学模型和传热模型,研究了脉冲激光参量(离焦量、脉宽和激光功率)对金刚石磨粒去除厚度的影响规律,为激光修整参量选择提供了指导。结果表明,激光功率、脉宽和离焦量是影响脉冲激光金刚石磨粒去除厚度的最直接的因素,金刚石磨粒去除厚度随着激光功率的增加而变大;随着脉宽的增加而减少;随着离焦量的增加而减少。借助CCD和激光三角位移测量仪对砂轮表面跳动进行在线监测、采用闭环控制系统控制Q开关,实现了砂轮的在线修整,获得了良好的地形地貌,降低了砂轮圆跳动度误差,达到良好的修整效果。

Numerical simulation and experiment for on-line truing and dressing of bronze-bonded diamond grinding wheels with laser

Based on both numerical simulation and experimental investigation, much research work has been done on on-line truing and dressing bronze-bonded diamond grinding wheel by acoustic-optic Q-switched YAG pulsed laser. A 3-D mathematical simulation model and a heat transfer model of single pulsed laser ablating the diamond abrasive was established by means of finite element method, where the process of diamond graphitization was taken into account. The removal depth of the diamond abrasive in different laser parameters (such as focal position, pulse width and laser power) was measured, and the relationship between them was analysed, which helped us to select optimal parameters. The results show that: the laser power, pulse width and the focal position are the direct effects of the removal depth of the diamond abrasive; it will increase along with the increase of laser power, and decrease along with the increase of pulse width and the focal position. The on-line grinding wheel dressing was achieved with closed-loop control, CCD and laser triangulation displacement measuring instrument which were used in control of Q-switch and the on-line monitoring of the circular run-out of the grinding wheel. After laser truing and dressing, the accuracy was further improved，the circular run-out error was reduced，and the surface topography was improved too．