导　　师： 陈根余;李力钧

学科专业： H0201

授予学位： 硕士

作　　者： ;

机构地区： 湖南大学

摘　　要： 该文采用声光调q yag脉冲激光径向辐射,对密实型结合剂(树脂和金属结合剂)超硬磨料砂轮(金刚石和立方氮化硼)进行修锐试验研究,并与传统机械修锐和连续激光修锐进行了比较.理论分析了声光调q脉冲激光修锐超硬磨料砂轮的机理,试验研究了单脉冲激光烧蚀凹坑和脉冲激光修锐的情况,总结出激光、工艺参数对修锐效果的影响特点和规律.由于结合剂和磨粒之间存在热物理、光学性质差异,可通过选择合理的脉冲激光功率密度去除结合剂,凸出磨粒,实现选择性去除.树脂结合剂砂轮的修锐主要是基于树脂材料的气化,瞬间形成凹坑,铜粉(填料)部分溅射;青铜结合剂砂轮的修锐以结合剂熔化为主,材料多以熔体形式排出体外,部分在凹坑边缘重凝. 理论分析得出声光调q yag单脉冲激光烧蚀热影响小,可展过选择合理工艺参数使单脉冲烧蚀凹坑相切或部分重叠,并以单脉冲试验为指导,合理选择激光参数进行修锐,达到选择性去除,得到满意的地形地貌.在该试验条件下,针对各种砂轮,总结出了激光参数对修锐效果的影响特点和规律.从修锐效果看,声光调q yag脉冲激光修锐优于传统机械修锐和连续激光修锐. Opto-acoustic Q-switched Nd: YAG pulse laser is used to dress densely bonded /(resin and bronze/) soperabrasives /(diamond and CBN/) wheels in orthogonal direction and the advantages ind disadvantages among pulse laser, conventional mechanical and continuous wave laser dressing on superabrasive wheels are compared. This experiment deals with surface craters ablated by single pulse laser and pulse laser dressing, theoreticalJy analyses the dressing mechanism of superabrasive wheels by opto-acoustic Q-switched pulse laser and summarizes the dressing features and disciplines of dressing effects influenced by laser and technology parameters. Due to the thermal-physical and optical differences between bonds and abrasives, suitable pulse power density is selected to remove bonds and protrude abrasives realizing the selective removal. The dressing mechanism of resin-bonded wheels is mainly based on vaporization by which the crater is instantaneously formed with copper powder partially ejecting while in dressing mechanism of bronze bonded wheels, the bonds is mostly melted, the materials are mostly ejected from the crater by means of melt, which partly resolidifies on the crater brim. Pulse power density directly influences ablation crater depth. With average laser power increasing, pulse repetition frequency and focal distances decrease, pulse power density and crater depth increases. Crater depth versus pulse power density, average laser power, pulse repetition frequency and focal distances are built up through experiment. Small heat effect of opto-acoustic Q-switched YAG pulse laser is concluded by theoretical analyis. Single pulse ablation craters are arranged in sequence or overlapped by selecting suitable technology parameter. Better surface topography can be obtained through selecting suitable laser parameter based on single pulse ablation experiment. Dressing features and disciplines of dressing effect influenced by laser parameter are summarized aimed at various grinding wheels in these experimental conditions. From dressing effect opto-acoustic Q-switched YAG pulse laser dressing is superior to conventional mechanical and continuous wave laser dressing.

关 键 词： 激光修锐 超硬磨料砂轮 声光调 激光器 单脉冲烧蚀 选择性去除

分 类 号： [TG665]

领　　域： [金属学及工艺]