单晶金刚石研磨方法与机理的研究

【作者】 李智；

【导师】 马勇；

【作者基本信息】 大连理工大学 ， 机械制造及其自动化， 2004， 硕士

【摘要】 超精密切削是超精密加工中的一个重要领域，它是一项内容广泛的新技术。使用精密的单晶金刚石刀具加工有色金属和非金属，能够直接切出超光滑的加工表面，这样就可以取代超精密磨削等精加工工序，极大的提高加工效率，同时也可以保证加工精度和加工表面质量。近些年来，单晶金刚石刀具已经深入到机械加工的各个领域，起着越来越重要的作用。因此，对单晶金刚石刀具的制作，研磨方法以及研磨机理的研究，已经受到了人们极大的关注。 金刚石的硬度大，耐磨性好，使得金刚石成为理想的刀具材料，但是与此同时也给单晶金刚石刀具的研磨带来了极大的困难。在研磨过程中既要提高磨削率，又要保证刃口质量。针对这个问题，本文从研磨效率入手，对金刚石研磨机进行了改造，分析了各种因素对磨削率的影响，深入的研究了单晶金刚石的研磨机理，并且通过试验的总结和以往经验的借鉴得出研磨单晶金刚石刀具的系统方法。 本文介绍了单晶金刚石刀具的发展状况，并且对单晶金刚石刀具的制作程序和方法以及刀具的设计也进行了详细的阐述。 在文章中，对金刚石研磨机进行了设计改造，使改造后的研磨机操作更加方便灵活，磨削效率显著提高，采用其对单晶金刚石刀具进行粗磨加工，降低了刀具的加工成本，具有很高的应用价值。 研磨效率一直是影响单晶金刚石刀具加工的一个重要问题。课题中通过大量的实验得出影响单晶金刚石刀具研磨效率的主要因素是：砂轮转速、轴向进给量、砂轮径向摆动频率。几项参数值的增加都会导致研磨效率的提高，但是根据实际情况的限制，各项参数应该合理匹配。 通过干研磨与湿研磨的对比试验，发现干研磨的效率远远高于湿研磨，因此得出结论：单晶金刚石刀具的研磨应该在干研磨状态下进行。 通过对陶瓷结合剂砂轮与金属结合剂砂轮的试验结果的对比，得出结论：陶瓷结合剂砂轮可以获得较高的研磨效率，金属结合剂砂轮能够获得更好的刃口质量。 为了提高刃磨工艺水平，就必须对单晶金刚石的刃磨机理进行深入的研究。文中通过扫描电镜进行研究与分析，发现单晶金刚石刀具的研磨主要以热化学去除为主，同时存在着脆性去除和疲劳去除。砂轮类型不同，各种去除方式所占比例有所不同。 最后通过对试验的分析，和以往经验的借鉴，得出单晶金刚石刀具研磨加工的系统方法：单晶金刚石刀具的粗磨主要以去除余量为主，应该尽量采用大粒度的砂轮，如果采用陶瓷结合剂砂轮，效率会更高，在研磨时应该注意寻找金刚石的好磨方向。半精磨可以采用细粒度的金属结合剂砂轮或陶瓷结合剂砂轮，并且应该考虑刃口的质量，为精磨打好基础。单晶金刚石刀具的精磨根据要求应该采用粒度尽可能细的砂轮，并且一定要考虑到影响刃口质量的重要因素，这样就必须对刀刃采取逆磨，并且在进给量给定的前提下，适当的增加研磨时间，只有这样才能获得更加完美的刃口质量。更多还原

【Abstract】 Super precision cutting is a important field of super precision machining, and it is a broad new technic. The super slippy surface can be got after colored metal and non-metal is c ut by single crystal diamond cutter. In this way it can take the place of super precision grinding, the efficiency can be increased , and the precision can be guaranteed, In these years, single crystal diamond cutter have been broadly used in the mechanics machining field, and hold a very important position. So studying manufacturing, grinding methods, grinding mechanism of single crystal diamond cutter has arose the attention of people.Single crystal diamond is very hard, and it is a good material of cutter. But at the same time, grinding diamond is a difficult work. On the course of grinding single crystal diamond cutter, the grinding efficiency should be increased and the blade quality ought to be guaranteed. To solve this problem, this paper start with grinding efficiency, and the diamond grinding machine is reconstructed, the grinding mechanism is studied in-depth. And by analyzing experimentations and using for reference to bypast experience, the systemic methods of grinding single crystal diamond cutter is got.In this paper the development status of single crystal diamond cutters is introduced. The manufacture procedure and methods of single crystal diamond cutters, the design of single crystal diamond cutters are presented.The grinding machine tool is reconstructed. After the machine is reconstructed, the grinding efficiency is enhanced, the handling of grinding machine became more agile. After the grinding machine is used on the course of rough grinding of single crystal diamond cutter, the machining cost of single crystal diamond cutter will be reduced. So reconstructing the machine has very practical value.Grinding efficiency is a important problem in machining diamond cutters. In this paper by analyzing experimentation results, primary factors which affect the grinding efficiency are got, these factors are speed of grinding wheel, swing frequency of grinding wheel and feed of shaft direction. Increasing these parameters can improve grinding efficiency. But these parameters should be matched logically in work.By the comparative experiment of wheel bonded by ceramic and wheel bonded by metal, it can be found that wheel bonded by ceramic can get higher grinding efficiency and wheel bonded by metal can get better blade.In order to increase the level of blade grinding, the grinding mechanism should be studied in-depth, In this paper experimentations are analyzed by scanning electron microscope, it is found that the themiochemical removal was dominating, the fatigue removal and brittle removal was secondary on the course of grinding single crystal diamond. Because grinding wheel is different, proportion of every removal mode is different.In the end by analyzing experimentation results, using for reference to bypast experience, the systemic blade grinding method is got. The main purpose is wiping off unwanted material on the course of rough grinding, the bigger grain wheel should be used. The grinding wheelwith ceramic bond will get higher grinding efficiency if it is used. Firstly, the grinding direction in which the grinding is higher should be found. The less grain wheel should be used in the course of half precise grinding, and the blade quality should be considered in order to prepare for precise grinding. On the course of precision grinding, the grain of wheel is less, the quality of blade is better, and the primary factors which affect blade quality should be considered. In order to get the best blade, the reverse grinding should be adopted, and the grinding time should be increased appropriately on the course of precision grinding.更多还原