大抛光模磁流变超光滑平面抛光技术研究

发布时间：2018-06-28 08:46

本文选题：磁流变抛光 + 超光滑平面　；参考：《湖南大学》2016年博士论文

【摘要】：近年来,随着信息电子技术、光电技术及半导体照明技术的迅速发展,超光滑平面元器件需求越来越大,这些表面要求达到亚纳米级表面粗糙度、微米级面形精度且无表面和亚表面损伤,传统超精密抛光技术由于耗时、成本高、易产生表面损伤,难以满足大批量生产的要求。磁流变加工被认为是一种极具前景的获取低损伤镜面的技术手段,然而,传统磁流变加工方法抛光点面积小,加工效率低。为解决上述问题,本文在比较分析国内外超光滑表面加工技术的基础上,提出了一种大抛光模磁流变超光滑平面抛光技术,为面形精度在微米级的超光滑平面提供一种高效低廉的无损抛光加工方法,大幅增加瞬时抛光面积,显著提高抛光效率,对磁流变平面抛光工艺进行优化,探讨其加工机理,研制了磁流变平面抛光机床,并开展了工业化应用方面的探索,制定了相关企业标准,通过了科技成果鉴定。主要工作及成果概括如下:(1)提出了直线气隙永久磁轭励磁的大抛光模磁流变平面抛光新方法,增大瞬时抛光面积,提高抛光效率。研究永久磁轭励磁装置磁场分布规律,探讨磁场分布对抛光模的影响,以K9玻璃为例,研究励磁间隙、工件尺寸、抛光时间对抛光面积的影响,初步验证永久磁轭励磁的磁流变平面抛光加工效果。(2)采用有限元分析结合正交法对永久磁轭励磁装置进行了优化,进一步提高磁流变液中磁场感应强度,增大气隙上方梯度磁场宽度,增大磁流变抛光模的屈服应力及工件与抛光模之间的接触面积。为评估优化效果,将优化前后的永久磁轭励磁装置进行试验对比,对优化前后的外部磁感应强度、磁流变抛光模、抛光痕面积及加工效果进行测试并分析比较。设计并仿真分析具有类高斯型磁场分布的永久磁轭,消除抛光痕两侧犁沟。(3)提出了直线摆动磁流变平面抛光方法,匀化材料去除量分布,改善平整度。建立工件在磁流变抛光模上的运动轨迹方程,以该轨迹方程为基础建立材料去除量分布数学模型,进行仿真分析,探讨摆动轨迹、摆动行程及摆动速率等加工参数对磁流变平面抛光加工性能的影响。(4)系统研究工艺参数,包括工作间隙、励磁间隙、铁粉浓度等,对抛光力、表面粗糙度、材料去除率和平面度的影响,并对磁流变平面抛光加工工艺的亚表面损伤消除效果进行了检测,分析磁流变平面抛光加工机理,建立法向力、切向力、表面粗糙度及材料去除率的数学模型。(5)研制了磁流变平面抛光机,并利用所开发的机床,针对蓝宝石及石墨材料加工进行了试验研究。(6)应用大抛光模磁流变平面抛光方法加工K9玻璃,获得了0.794 mm3/min的最大体积去除率、PV 1μm的面形精度和Ra 0.6 nm的表面粗糙度;加工蓝宝石,获得了4.63 mg/h的最大材料去除率及Ra 0.3 nm的最佳表面粗糙度;加工石墨,获得了3.1 mg/min的最大材料去除率及Ra 10 nm的最佳表面粗糙度。
[Abstract]:In recent years, with the rapid development of information electronic technology, photoelectric technology and semiconductor lighting technology, the demand for ultra-smooth planar components is increasing. Due to the time consuming, high cost and easy to produce surface damage, the traditional ultra-precision polishing technology is difficult to meet the requirements of mass production. Magnetorheological machining (MRM) is considered to be a promising technique for obtaining low damage specular surfaces. However, traditional MRM methods have a small polishing point area and low processing efficiency. This paper provides a high efficiency and low cost nondestructive polishing method for the ultra-smooth plane with surface shape precision in micron scale, increases the instantaneous polishing area and improves the polishing efficiency significantly, and optimizes the polishing process of MRF plane, and probes into its processing mechanism. The magnetorheological plane polishing machine bed has been developed, the industrial application has been explored, the related enterprise standard has been established, and the scientific and technological achievements have been identified. The main work and achievements are summarized as follows: (1) A new method of magneto-rheological plane polishing of large polishing mode with linear air gap permanent magnetic yoke is proposed to increase the instantaneous polishing area and improve the polishing efficiency. The distribution of magnetic field of permanent yoke excitation device is studied, and the influence of magnetic field distribution on polishing die is discussed. Taking K9 glass as an example, the effects of excitation gap, workpiece size and polishing time on polishing area are studied. The processing effect of magneto-rheological plane polishing of permanent magnetic yoke is preliminarily verified. (2) the excitation device of permanent magnetic yoke is optimized by finite element analysis combined with orthogonal method, and the magnetic field induction intensity in magnetorheological fluid is further improved. Increasing the gradient magnetic field width above the air gap, increasing the yield stress of the magnetorheological polishing die and the contact area between the workpiece and the polishing die. In order to evaluate the optimization effect, the permanent magnetic yoke excitation device before and after optimization was tested and compared, and the external magnetic induction intensity, the magnetorheological polishing die, the polishing mark area and the machining effect were tested and compared before and after the optimization. The permanent yoke with Gao Si magnetic field distribution is designed and simulated to eliminate the furrows on both sides of the polishing mark. (3) the linear swing magnetorheological plane polishing method is proposed to homogenize the distribution of material removal and to improve the smoothness. The motion trajectory equation of the workpiece on the magnetorheological polishing die is established. Based on the trajectory equation, the mathematical model of material removal quantity distribution is established, and the simulation analysis is carried out, and the swing trajectory is discussed. The influence of machining parameters, such as swing stroke and swing rate, on the processing performance of MRF. (4) the process parameters, including working gap, excitation gap, iron powder concentration, polishing force, surface roughness, etc. The effect of material removal rate and planeness on the subsurface damage elimination of MRF plane polishing process was examined, and the mechanism of MRF processing was analyzed, and the normal and tangential forces were established. The mathematical model of surface roughness and material removal efficiency. (5) A magnetorheological plane polishing machine was developed, and the developed machine tool was used. The processing of sapphire and graphite materials was studied. (6) the maximum volume removal rate of 0.794 mm3/min and the surface precision of PV1 渭 m and the surface roughness of Ra 0.6 nm were obtained by using the method of large polishing die and magnetorheological plane polishing method to process K9 glass; The maximum material removal rate of 4. 63 mg/h and the best surface roughness of Ra 0. 3 nm were obtained by machining sapphire, and the maximum material removal rate of 3. 1 mg/min and the optimum surface roughness of Ra 10 nm were obtained by machining graphite.
【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG580.692

【参考文献】