单晶蓝宝石整流罩磁控研磨技术研究

发布时间：2018-08-12 19:34

【摘要】：蓝宝石具有机械强度高、导热率好、耐化学腐蚀及光通波段范围宽等优点,因而被广泛用作高马赫导弹及高速飞行器的整流罩材料。但目前的蓝宝石整流罩研磨加工存在效率低,易产生裂纹、划痕和崩边等表面缺陷,这严重制约了蓝宝石整流罩的应用。磁控研磨加工技术具有适应性强、精度高和加工表面质量好等优点,可将其应用于蓝宝石整流罩的研磨加工。本文通过化学复合镀法制备出金刚石相对含量较高的磁性磨料,对蓝宝石整流罩磁控研磨加工实验进行研究,系统分析了主要工艺参数对材料去除率和表面粗糙度的影响,探讨了整流罩磁控研磨加工前后的球度误差和表面质量。论文的主要工作与成果如下:(1)开展了化学复合镀制备磁性磨料过程中金刚石颗粒的吸附与沉积机理研究,建立了相应的理论模型,分析了镀液温度、镀液中悬浮的金刚石颗粒浓度、金刚石颗粒的粒径大小以及基体粉末的形状和粒径大小对磁性磨料镀层中金刚石相对含量的影响规律;进行了化学复合镀实验,研究了镀液金刚石浓度及金刚石粒径大小对镀层中金刚石相对含量的影响规律。(2)对蓝宝石整流罩磁控研磨工具进行了总体结构设计,建立了研磨工具的二维静态磁场有限元模型,仿真分析了磁极厚度、磁极头表面开槽数量、开槽宽度和槽间角度对加工间隙磁场强度及其梯度的影响;利用仿真结果优化改进了磁控研磨工具的结构并研制了蓝宝石整流罩磁控研磨工具。(3)进行了蓝宝石整流罩磁控研磨加工实验,研究了研磨罩板厚度、主轴转速、乙二胺浓度以及研磨时间对材料去除率及表面粗糙度的影响;综合考虑蓝宝石整流罩的材料去除率和表面粗糙度,得到蓝宝石整流罩磁控研磨加工最佳工艺参数组合,在该组合下材料去除率为142μm3/min,表面粗糙度为93nm,整流罩表面的球度误差由初始的54.54μm降低到11.64μm,且其表面质量显著提高。
[Abstract]:Sapphire has the advantages of high mechanical strength, good thermal conductivity, chemical corrosion resistance and wide optical band, so it is widely used as a fairing material for high Mach missiles and high speed aircraft. However, there are some surface defects in sapphire fairing, such as low efficiency, easy to produce cracks, scratches and flanging, which seriously restrict the application of sapphire fairing. Magnetic controlled grinding technology has the advantages of high adaptability, high precision and good surface quality, so it can be applied to the grinding of sapphire fairing. In this paper, the magnetic abrasive with relatively high diamond content was prepared by electroless composite plating. The experiment of magnetic controlled grinding of sapphire fairing was studied, and the influence of main process parameters on material removal rate and surface roughness was analyzed systematically. The sphericity error and surface quality of the fairing before and after magnetic controlled grinding are discussed. The main work and achievements are as follows: (1) the adsorption and deposition mechanism of diamond particles in the preparation of magnetic abrasive by electroless composite plating has been studied, the corresponding theoretical model has been established, and the bath temperature has been analyzed. The effect of the concentration of diamond particles suspended in bath, the size of diamond particles and the shape and size of matrix powder on the relative content of diamond in magnetic abrasive coating were studied. The effect of diamond concentration in bath and diamond particle size on the relative content of diamond in the coating was studied. (2) the overall structure of the magnetic controlled grinding tool for sapphire fairing was designed. A two-dimensional static magnetic field finite element model of grinding tool is established. The effects of the thickness of magnetic pole, the number of slots on the surface of magnetic pole head, the width of slot and the angle between slots on the magnetic field intensity and gradient of machining gap are simulated and analyzed. The structure of the magnetic controlled grinding tool is optimized by using the simulation results and the magnetic controlled grinding tool for the sapphire fairing is developed. (3) the experiment of the sapphire fairing magnetically controlled grinding is carried out, and the thickness of the abrasive cover plate and the rotation speed of the spindle are studied. The effects of ethylenediamine concentration and grinding time on the removal rate and surface roughness of the sapphire fairing were studied, and the optimum processing parameters were obtained by considering the material removal rate and the surface roughness of the sapphire fairing. The material removal rate is 142 渭 m 3 / min, the surface roughness is 93 nm, the sphericity error of the fairing surface is reduced from 54.54 渭 m to 11.64 渭 m, and the surface quality is improved significantly.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG580.68

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