【作者】 孙康健；

【导师】 陈根余；

【作者基本信息】 湖南大学 ， 机械工程， 2011， 硕士

【摘要】 青铜CBN砂轮具有优良的磨削性能,在精密、超精密磨削,难加工材料成型、高效磨削和磨削自动化中有广泛的应用前景。但由于CBN硬度仅次于金刚石,采用传统的基于力的修整方法修整青铜CBN砂轮很难达到使用要求,严重影响了青铜CBN砂轮优良磨削性能的充分发挥。激光修整技术在修整超硬磨料砂轮方面有其独特的优势,被广泛认为是一种非常有发展前途的方法。本文通过典型的试验及理论推导,总结出了一种在保证砂轮修整精度和效率的前提下,针对不同砂轮的修整,可有效的缩小激光设备及参数的选择范围的方法。采用自制200W声光调Q Nd:YAG激光器,并结合机械修整方法,对青铜CBN砂轮进行了复合修整试验研究。经过高功率、大脉冲能量激光粗修,碳化硅滚轮粗修,最后用低功率、小脉冲能量激光精修的方法,将青铜CBN砂轮表面跳动量由400μm修整到28μm。并用体视显微镜对砂轮表面形貌进行了观察,通过铝片刮擦试验和磨削力试验对砂轮的磨削性能进行了研究。结果表明:经上述方法修整过的砂轮,其修整几何精度高、表面形貌良好、磨粒凸出高且分布均匀、磨削性能优良。在修整精度、效率、磨削性能各方面均优于机械法修整的砂轮。采用自制200W声光调Q Nd:YAG激光器对青铜CBN砂轮进行了变角度入射烧蚀试验,研究了激光入射角度对砂轮修整效率的影响。结果表明:当入射角度为30°到40°时,修整效率最高。采用自制200W声光调Q Nd:YAG激光器,在入射角为30°的情况下,对青铜CBN砂轮进行了修整试验,并对砂轮表面形貌进行了显微观察。其表面形貌良好,与激光垂直入射修整结果的不同点在于:磨粒背光面存在“山坡”状结合剂突起,并粘附在磨粒表面。经分析,这将增强结合剂对磨粒的把持力,提高砂轮的磨削性能。更多还原

【Abstract】 With excellent grinding performance, bronze-bonded CBN grinding wheel has a wide application prospect in the field of precision , ultra-precision, high efficiency grinding, grinding automation and difficult processing material forming. Because of the hardness of CBN is only lower than the diamond, 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 bronze-bonded CBN grinding wheel. The laser truing and dressing technology has unique advantages for the truing and dressing of super-abrasive wheel, and has been widely recognized that it was a very promising method.Through typical experiment research and theoretical derivation, a method which can reducing the option range of laser and parameters effectively is obtained for different types wheels, under the premise of guaranteeing the accuracy and efficiency.The bronze-bonded CBN grinding wheel is trued and dressed with self-made 200W acoustic-optic Q-switched Nd: YAG laser, combining mechanical method. The surface circular run of bronze-bonded CBN grinding wheel reduces from 400μm to 28μm, by the method of truing and dressing in high power and high pulse energy laser, and truing and dressing by silicon carbide wheel secondly, and truing and dressing in low power and low pulse energy laser lastly. The morphology of wheel surface after laser truing and dressing is analyzed by means of stereo microscope. And researches the grinding performance through scratching aluminum and measuring grinding force experiments. The results prove that: after trued and dressed by this method, the surface circular run is low, and the morphology is good. The CBN abrasives have ideal height, good grinding performance and are evenly distributed at the same time. All performance are better compared with the wheels trued and dressed by mechanical method.The bronze-bonded CBN grinding wheel is ablated in different angles with self-made 200W acoustic-optic Q-switched Nd: YAG laser. And researches the influence of angles for the efficiency of the laser truing and dressing. The results prove that: the efficiency is highest when the angle is between 30 degree and 40 degree. True and dress bronze-bonded CBN grinding wheel in 30 degree with self-made 200W acoustic-optic Q-switched Nd: YAG laser, and analyze the morphology of wheel surface. The morphology of wheel surface is good. And compared with the wheel trued and dressed by laser in 0 degree the difference is that there is some bond against CBN abrasives looked like hills. That will improve the holding force of CBN abrasives and the grinding performance.更多还原