摩擦化学抛光单晶金刚石的工艺研究

发布时间：2018-05-17 00:03

  本文选题：单晶金刚石 + 摩擦化学　； 参考：《大连理工大学》2015年硕士论文

【摘要】：金刚石在力学、热学、光学、电学、声学和化学稳定性等方面有着无与伦比的优异性质,使金刚石成为制作切削工具、半导体电子器件、高功率激光窗口、声波滤波器和耐磨损涂层等元部件的理想材料。随着金刚石合成技术的日臻完善,人造金刚石年产量早已超过46亿克拉,各种性能得到开发利用。目前,人造金刚石在形状和表面质量无法直接满足应用要求,必须通过研磨或抛光,达到一定的表面粗糙度和面型精度后才能被使用,但单晶金刚石优异的理化性质使单晶金刚石加工制造工艺的难度很大。摩擦化学抛光技术既保证金刚石加工的效率与精度,又具有设备简单价格低廉等方面优势,本文选择该技术加工单晶金刚石,利用WMoCr抛光盘研究单晶金刚石的抛光工艺和相关理论,主要研究内容和结论如下：(1)以机械合金化法制备的微细WMoCr合金粉末为原料,研究热压烧结参数对材料致密度和硬度的影响,并利用扫描电镜(SEM)对材料的显微组织进行观察。结果表明：机械合金化和热压固相烧结相结合的方法可以制备出的高致密度、高硬度的合金材料,在烧结温度为1400℃、压力为30 MPa、保温时间为30 min的工艺条件下,所制备的WMoCr合金材料相对密度为96.49%,硬度为777.78 HV。(2)利用机械合金化和热压固相烧结制备的高性能的WMoCr合金盘,对单晶金刚石的摩擦化学抛光工艺进行研究。在不同抛光压力和速度下抛光20 min,考察金刚石的去除率和表面质量、抛光盘的磨损量和氧化程度,制定出合理的抛光参数。结果表明：WMoCr抛光盘性能优异,较低的抛光参数5.67 MPa和8.38 m/s下,获得较高的金刚石去除率2.3 μm/min,同时较好的控制了金刚石表面质量、抛光盘的磨损量和氧化等问题。(3)基于单晶金刚石表面形貌的分析,建立了金刚石表面微凸体的四棱台结构几何模型,考虑抛光过程中材料特性和摩擦接触情况,计算热流密度、热流分配系数和空气对流系数等热载荷。在抛光参数80N和8000 r/min下,利用ANSYS热分析软件对单晶金刚石摩擦化学抛光过程中的温度场进行仿真,仿真结果与实验测量结果基本相符。(4)通过对金刚石抛光背面测量温度与其去除率关系的分析,得出金刚石抛光表面达到石墨化的临界抛光参数6000 r/min和65 N,通过热分析软件ANSYS6对该抛光参数下金刚石温度场进行求解,计算出此时整个金刚石温度分布范围。结果表明：金刚石石墨化温度的最低临界值在624.5～658.1℃之间。
[Abstract]:Diamond has unparalleled excellent properties in mechanics, heat, optics, electricity, acoustics and chemical stability, making it a cutting tool, semiconductor electronic device, high power laser window, etc. Sound filter and wear-resistant coating and other components of the ideal material. With the improvement of diamond synthesis technology, the annual production of synthetic diamond has already exceeded 4.6 billion carats, and various properties have been developed and utilized. At present, artificial diamond can not meet the requirements of application directly in shape and surface quality. It must be ground or polished to achieve a certain surface roughness and surface precision before it can be used. However, the excellent physical and chemical properties of single crystal diamond make it very difficult to process and manufacture single crystal diamond. The tribochemical polishing technology not only guarantees the efficiency and precision of diamond machining, but also has the advantages of simple equipment and low price. In this paper, we choose this technology to process single crystal diamond. The polishing technology and related theory of single crystal diamond were studied by WMoCr polishing disc. The main research contents and conclusions are as follows: (1) the fine WMoCr alloy powder prepared by mechanical alloying method is used as raw material. The effect of hot pressing sintering parameters on the density and hardness of the materials was studied, and the microstructure of the materials was observed by scanning electron microscope (SEM). The results show that the high density and high hardness alloy materials can be prepared by the combination of mechanical alloying and hot pressing solid sintering under the conditions of sintering temperature of 1400 鈩，

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