平行于电场的磁场对磁力电解复合抛光的影响

在传统的磁力电解复合抛光中,外加磁场的方向与电场方向垂直。通过给电解抛光外加一个平行于电场的磁场,对带电离子的运动状况进行分析,建立了带电离子运动的数学模型。并求出了带电粒子的速度方程和轨迹方程,分析了磁场在磁力电解复合抛光中的作用。由于所加磁场的作用,减小了电化学反应的浓差极化,加速了电化学反应速度和效率。通过实验,验证了该模型的合理性和对磁场功能分析的正确性。     

磁力电解复合抛光中电解液的选配

磁力电解复合抛光工艺在难加工材料的精加工中被广泛使用,电解液的选配是影响该工艺的一个重要因素。文中对磁力电解复合抛光工艺中电解液的选配进行了研究,对磁力电解复合抛光中电解液的基本要求进行了分析,对常见电解液的性能进行了归纳和比较,并根据抛光过程中电解液的使用,得出了磁力电解复合抛光中电解液的选配原则。     

电解磨料喷射复合抛光工艺的研究与应用

研究了电解磨料喷射复合抛光新工艺及抛光特点，并应用于模具抛光。     

电解机械复合抛光试验及其过程分析

通过研究工艺试验中的表面粗糙度和去除量随时间变化的关系,以及切屑微粒的形貌的提取分析,证明电解机械复合抛光的效率高于纯机械抛光和纯电解抛光,而且在其他工艺条件相同时可以获得更低的极限表面粗糙度值,但是在获得同样表面粗糙度时,复合加工单位面积去除的材料更多。切屑和加工后表面形态显示电解作用主要在工件表面的凸起棱边上,这正是复合加工较机械加工的优势所在。     

巴氏合金模具的机械电解复合抛光研究

针对具有复杂曲面的巴氏合金模具的难抛光，低效率等问题，在数控机床上将电解加工和机械抛光相复合，对模具型腔进行高效抛光，获得了良好的表面质量，由于采用CAD／CAM技术，保证了加工精度，提高了加工效率，文中探讨了数控机床机械电解复抛光的机理，并分析了抛光结果。     

S136不锈钢电解机械复合抛光

为了解决S136不锈钢机械抛光和电化学抛光存在的效率低、质量差、污染大等问题而进行电解机械复合抛光的研究。根据S136不锈钢的化学特性,使用新型电解液,结合高频窄脉冲电源对其进行电解机械复合抛光实验,通过调整加工参数,使不锈钢工件的表面粗糙度降低到Ra0.08μm。与其它抛光方式相比,该方法具有污染小、成本低、效率高、加工质量好等优点。     

往复电解机械复合抛光工艺的试验研究

介绍了电解机械复合抛光的新工艺及其试验装置.通过研究实验中的表面粗糙度和去除量随时间变化的关系,初步得出一系列工艺参数.磨料的机械切削作用不仅能去除工件电化学反应产生的金属钝化膜,同时也去除金属材料.研究工艺参数对高效获得光整表面的同时尽可能地减小工件尺寸变化量有很大意义.     

不锈钢电解—机械复合抛光新工艺的研究

在电解加工和机械研磨的基础上，把电解阳极溶解与合成纤维无纺布上所粘结磨料的研磨有机地结合起来，试验了一种新的不锈钢电解机械复合抛光法，并总结了较合理的工艺参数，不锈钢表面的短时间的抛光加工后，表面光洁度可接近镜面。     

新型复合表面抛光技术

随着生产技术的不断进步,为了提高抛光效果,出现了化学一机械抛光(Chemical-MechanicalPolishing,简称CMP)、电解一机械抛光、超声波一电解抛光、磁力一电解抛光等多种复合抛光技术.为适应现代工业对抛光技术进展的需要,对几种复合抛光方法的原理、特点以及应用范围进行了叙述和总结.     

磁场分布对磁性复合流体抛光材料去除率的影响

针对光学玻璃抛光效率和抛光精度不断提高的需求,提出采用磁性复合流体(Magnetic compound fluid,MCF)抛光轮进行抛光加工的方法,并自行研制出相应的抛光试验装置。运用标量磁位法、矢量叠加原理,建立MCF抛光轮外部空间磁场分布的解析表达式,通过对比分析磁铁磁场强度的解析计算结果和实际测量结果,说明解析表达式能较好地反映抛光轮外部空间磁场的分布规律。以Preston方程为依据,分析磁场产生的磁化压力对被加工工件表面材料去除率的影响规律;在自行研制的试验装置上利用磁性复合流体对熔融石英玻璃进行120 min的往复抛光加工,当两个环形磁铁采用NS-SN和NS-NS磁极布置方式时,最大材料去除深度分别为13 m和8 m,而且采用NS-NS磁极布置方式时,在工件中部的材料去除量几乎为零,因此NS-SN磁极布置方式由于其产生的磁场强度较大,从而导致其材料去除率也较大,验证不同磁场分布对熔融石英玻璃材料去除率的影响。     

立、卧式磁性复合流体抛光对比实验研究

针对磁性复合流体(MCF)抛光的两种抛光头,进行MCF抛光特性对比实验研究。开展了黄铜H26的平面抛光实验,调查立式和卧式抛光头分别对工件材料去除率、表面形貌与粗糙度以及MCF水分损耗等抛光特性的影响。实验结果表明,卧式MCF抛光能够较快地降低表面粗糙度,获得较高的材料去除率,MCF水分损失相对较快;立式MCF抛光能够在相对较长时间内获得稳定的材料去除率和表面粗糙度,MCF水分损失也较为平稳。     

磁流体研磨装置中磁场加工区的设计

针对特定的加工要求 ,设计磁流体研磨装置中磁场加工区的重要参数 ,并分析验算设计的合理性     

非球面磁性复合流体抛光路径误差分析与仿真

针对光学系统中对非球面元件的精度要求,设计了直线光栅式的抛光轨迹,并用磁性复合流体以这一抛光轨迹抛光非球面。根据抛光轨迹和非球面方程计算出每个抛光点的坐标;根据抛光点坐标和抛光头的抛光姿态计算出对应的抛光头中心点的坐标;建立相邻两抛光点的弓高误差模型,仿真出弓高误差模型并分析弓高误差的变化规律;根据弓高误差变化规律,用等弓高误差变步长控制算法实现弓高误差的一致性,提高加工质量。     

光学非球面磁性复合流体抛光运动控制算法设计

为了实现高精度光学非球面元件超精密抛光加工的需要,设计了光学非球面磁性复合流体抛光运动控制算法。通过分析光学非球面磁性复合流体抛光加工原理,建立抛光头在加工过程中相对非球面表面的位态变换关系,采用D-H法建立抛光试验台运动学模型,求解抛光过程中抛光头位姿量,运用逆向运动学求解方法计算试验台运动量;开展工艺实验,对该运动控制算法进行验证。实验结果表明,所设计的抛光运动控制算法能够准确指导光学非球面元件抛光加工。     

光学非球面磁性复合流体抛光运动控制及误差分析

针对精密光学系统中对高精度光学非球面元件的加工需求,设计磁性复合流体抛光的直线光栅式运动轨迹,并通过运动轨迹和非球面方程计算出各抛光加工点坐标。根据工件表面形貌和抛光头运动姿态设计了抛光加工路径,建立各抛光加工点间的弓高误差模型,通过模型对工件表面弓高误差变化规律进行仿真分析。仿真结果表明,弓高误差会随着Y轴上步长的增大而增大。这对非球面超精密加工具产生了深远的影响,促进了光学元件超精密高效制造技术的发展。     

Analysis of the polishing ability of electrogenerated chemical polishing

Electrogenerated chemical polishing (EGCP) had been proved effective in improving both the smoothness and the flatness of copper surface in our previous work. In this paper the polishing ability, defined as the ratio between the material removal rate at the peak and at the valley of a rough surface, is studied theoretically and experimentally. In a mathematical model, the effects of the special wavelength L, the peak-to-valley height h of the workpiece surface profile and the working distance d between working electrode and workpiece surface on the polishing ability are studied. The results show that the polishing ability decreases with increasing the working distance and finally approaches the value (d + h)/d, if L is much larger than d. However, the effect of the working distance on polishing ability is negligible, if L is close to or less than d. The polishing ability also decreases with h decreasing. Based on the above analysis, an analytical expression of the polishing ability of EGCP is given. For validating the theoretical analysis, a copper surface is polished by EGCP and the change of the surface profile is measured and analyzed using the analytical expression. The measured polishing ability agrees well with the simulation results.     

Investigation on the polishing of aspheric surfaces with a doughnut-shaped magnetic compound fluid (MCF) tool using an industrial robot

Aspheric elements have become essential optical surfaces for modifying optical systems due to their abilities to enhance the imaging quality. In this work, a novel method employing a doughnut-shaped magnetic compound fluid (MCF) polishing tool, and an industrial robot was proposed for polishing aspheric surfaces. Firstly, investigations on the MCF tool, including the formation process and geometry, were conducted to form an appropriate polishing tool. The distribution of abrasive particles was observed using SEM and EDX mapping. Thereafter, a conic workpiece constructed from 6061-aluminum alloy was selected as the workpiece, which was used to discover the effects of the parameters on the polishing ability of aspheric surfaces. Finally, a polishing experiment was conducted with an aspheric element under the optimized conditions. The obtained results are shown as follows. (1) A relatively regular MCF tool was obtained when the eccentricity (r), amount of MCF slurry supplied (V), revolution speed of the MCF carrier and magnet (n_c and n_m, respectively) were given at appropriate values. (2) Abrasive particles entrapped in or attached to the clusters were observed abundantly on the MCF tool sample. (3) The surface profile of the conic workpiece after 60 min of polishing indicated that material was removed evenly, and an annular polishing area was attained. Meanwhile, a higher material removal rate and better surface roughness were achieved with a smaller working gap (h) and larger volume of the MCF slurry supplied (V). (4) The roughness (Ra) of the aspheric surface decreased from 49.81 to 10.77 nm after 60 min of polishing. The shape retention obtained a Pearson correlation coefficient (Pcc) of 0.9981, which demonstrated that this novel method is appropriate for polishing aspheric elements.     

Abrasive jet polishing of micro-channels using compound SiC abrasives with compound additives

Recently, one of the most important problems in merchandise and stock markets all over the world is increasing prices. Tehran’s commodity market seems to be one of the main reasons for Iran’s economic growth which is confronted with the mentioned problem. Last year, the prices of the majority of petrochemical commodities have been increased significantly. Some political and economic analysts proposed two main factors (one internal and the other external) for this event. They argued that these factors have affected the Iranian economical body and its merchandise and stock market. The internal factor was the start of the implementation of targeted subsidy reforms by the Iranian government and its psychological effects. Some other analysts believed that sanctions against Iran’s government and companies which are signed by the UN Security Council in 2009 are the main reasons. This paper analyzes the exchange data in Tehran Mercantile during a 1-year time span and identifies the main factors influencing the prices using multivariant analysis and forecasting methods. To do this, a list of potential factors prepared based on expert opinions and data related to five petrochemical commodities which have been faced with the price fever have been collected. By doing analysis, it is revealed that the main reason for the occurrence of this event is speculation. This paper is a response to those analysts who introduced other reasons for this event without considering all aspects of the problem.