【作者】 尤卫民；

【导师】 陈根余；

【作者基本信息】 湖南大学 ， 机械制造及其自动化， 2007， 硕士

【摘要】 青铜金刚石砂轮具有异常优良的磨削性能,由于其本身特性,采用传统的基于力的修整方法修整超硬磨料砂轮很难达到使用要求。激光修整作为一种非接触修整方法,基于热的熔化和气化机理,是一种极有前景的超硬磨料砂轮修整方法。声光调Q脉冲激光以其峰值功率高、占空比小、脉宽短、重复频率高、易于控制等特点被认为是超硬磨料砂轮修整的合适光源。参考数值模型的理论计算,合理选择激光参数和运动参数,利用自行研制的声光调Q YAG激光修整系统和高速磨削试验台进行青铜金刚石砂轮修整试验。为便于对比,进行了碳化硅滚轮修整试验。分别得到了不同功率密度、脉冲频率、离焦量等激光参数下以及碳化硅滚轮修整后青铜金刚石砂轮表面的微观形貌。对激光修整后的青铜金刚石砂轮进行了磨削力、磨削温度以及磨削试件表面粗糙度等高速磨削性能对比试验研究。激光修整和磨削性能试验交叉进行,把自制测温试件安装在测力仪上,对磨削力和磨削温度进行同步测量。为便于得到较好的磨削温度信号,采用了干磨方式。对比声光调Q YAG脉冲激光不同参数修整后青铜金刚石砂轮在高速磨削时磨削性能,总结出青铜金刚石砂轮的磨削力、磨削温度、磨削试件表面粗糙度随功率密度、脉冲频率、离焦量等激光参数的变化规律,得到了优化的激光修整参数组合;通过比较激光修整和碳化硅滚轮修整后青铜金刚石砂轮的高速磨削性能,发现优化的激光参数修整后砂轮的磨削力和磨削温度均低于滚轮修整。更多还原

【Abstract】 With excellent grinding performance, Bronze-bonded Diamond Grinding wheels have a wide application prospect in the field of precision, ultra-precision, high efficiency grinding, grinding automation and difficult processing material forming. Because of the ultrahigh hardness of super-abrasive wheels, the conventional mechanical truing and dressing methods based on force interaction are nearly impossible to meet the requirement for grinding process, which really affects the grinding performance of super-abrasive wheels. Laser truing and dressing method based on thermal interaction without force interaction, was thought to be a promising method. With high peak power, low duty ratio, short pulse duration, high repetition frequency and controllable feature, the acoustic-optic Q-switched pulsed laser is considered to be suitable for truing and dressing super-abrasive wheels.Experimental study on truing and dressing super-abrasive wheels with laser was taken out. Acousto-optic Q-switched YAG pulsed laser machine, developed by our team, was employed to dress bronze bonded diamond wheels in orthogonal direction, utilizing the closed loop of the control system to control the output of the laser pulse. According to numerical model result, with proper laser parameter (power density/average power/pulse repetition frequency/focus-off parameter) and technics parameter (moving speed and rotation speed of grinding wheel), bronze and diamond was wiped off selectively. Experimental study on carborundum truing and dressing method was also taken out to compare with the laser truing and dressing method. In addition to microcosmic appearance of the wheel trued and dressed with laser and carborundum, the truing and dressing effect affected by laser parameter was obtained.As a new method, laser truing and dressing needs to be checked by the grinding capability of the wheel, and the grinding capability is also helpful for optimizing the laser parameter. With the high grinding platform, high speed grinding experiment was taken out in the national engineering research center for high efficiency grinding. Change trend of the wheel grinding force、grinding temperature and the roughness of the workpiece surface along with laser dressing parameters was obtained. Compared with the carborundum truing and dressing method, it was established that, when grinding alumina, grinding force and grinding temperature is smaller dressed by laser with suitable parameters.更多还原