电火花加工微细轴的探讨

在微细轴的块电极反拷电火花加工中,针对反拷进给方式的不同,进行了四种对比试验研究,并对试验结果进行分析比较,然后选择其中一种方法进行微轴加工,效果良好.     

基于块电极反拷法的工具电极在线制作与修正

微细电火花技术在加工微小孔或具有复杂形状的零件时,由于工件尺寸较小,电极的制备比较困难。本文利用块电极反拷法在线制作和修正工具电极,所获得的电极同轴度较好,长径比L/R在30以上,平均直径为0.012mm,尖端直径在5μm左右。加工出了相应的微小孔,精度在±0.003mm。总结了反拷法的加工工艺特性和电参数的选择,为以后的MEMS器件加工提供好了有效的方法。     

利用块电极反拷法在线制作和修正工具电极

微细电火花作为一种高柔性、低成本的微细加工技术,在MEMS加工应用中表现出了较优异的加工性能。但微细电火花技术加工微小孔或微小的复杂形状时,由于孔径较小,电极的制备比较困难,本文利用块电极反拷法在线制作和修正工具电极,取得了较好的效果。     

微细工具电极在线制作技术及实验研究

本文提出了一种在线制作微型工具电极的新方法。该方法是基于电化学微加工,通过反复交换工具电极和工件的极性,进行相互加工获得与电化学微加工相适应的微型工具电极。由于该过程在线进行,因此可以避免因两次夹紧工具电极造成的位置误差和夹紧误差,并可以大大提高加工精度。该方法对于电化学展成微加工来说是非常重要的。通过实验,稳定的加工出了最小直径为20μm的工具电极。     

微米尺度线电极的电化学腐蚀法制备

微细电化学线切割加工是最近出现的一种微细加工新方法。本文基于电化学腐蚀原理,制备微细电化学线切割加工中使用的微米尺度线电极。建立了腐蚀过程理论模型,通过测量线电极的电阻变化来实时监测线电极腐蚀过程中的直径大小,并基于虚拟仪器技术建立了线电极制备监控系统。通过试验对钨线电极的腐蚀过程进行分析,得出监控系统的直径计算值与实际值误差低于10%。最后,利用此方法制备出直径5μm的钨线电极。     

电化学腐蚀法制备微圆柱电极数值模拟

基于电化学腐蚀原理,利用COMSOL Multiphysics有限元分析软件进行微圆柱电极电解加工数值模拟研究:采用传导介质DC模式和瞬态移动网格ALE模式联合建模,并将试验参数(如电压、电极丝浸入溶液深度、溶液浓度等)对试验结果的影响进行了分析。研究表明,该方法切实可行,能够减少工艺试验次数,缩短加工周期。     

微细电极在线制备专利技术的现状和趋势分析

对微细电极在线制备技术有关的专利技术做了全面检索,基于对相关专利申请的分析,对微细电极在线制备技术进行了梳理,总结出微细电极在线制备技术的主要技术分支和具体实现手段,以期对从事微细电极在线制备技术领域的有关科研单位、企业和个人提供参考。     

自成型微细电极制备技术研究

以目前微细电火花加工中微细电极常用的制备技术为基础。提出了自成型微细电极制备技术。通过研究,掌握了自成型微细电极制备技术工艺关键。并与传统制备方法的反拷块法进行了实验对比。获得了较为理想外形尺寸精度、长径比的电极。     

电化学腐蚀法制备微细群圆柱

提出了微细群圆柱结构电化学腐蚀加工法及其形状和尺寸控制方式。根据电化学腐蚀基本原理,通过有限元分析计算群圆柱电化学腐蚀加工过程中的电场分布,优化设计阴极形状。开展了电化学腐蚀法制备微细群圆柱结构的工艺试验,获得了良好的试验结果。     

微细球状电极制备研究

微细球状电极在精微加工、测量领域有很大的应用空间,为制备低成本、高精度微细球状电极,提出新的制备工艺,在微细电解加工机床上运用微细电化学刻蚀(Micro electro-chemical machining,micro-ECM)—单脉冲放电加工(One pulseelectro discharge,OPEG)组合技术制...     

Laminated fabrication of 3D queue micro-electrode and its application in micro-EDM

3D micro-electrode used in micro electrical discharge machining (micro-EDM) is difficult to be fabricated. Based on laminated object manufacturing (LOM) process, this paper superimposed multilayer 2D micro-structures together to fit out 3D micro-electrode and applied it in micro-EDM to process 3D micro-cavity mold. Firstly, 100-μm-thick Cu foils were cut by wire-electrical discharge machining (WEDM) to obtain multilayer 2D micro-structures, and then these 2D micro-structures were connected together to fit out 3D micro-electrode through vacuum pressure thermal diffusion welding. Secondly, under the effect of 80-V voltage, 0.2-MHz pulse frequency, 800-ns pulse width, and 4200-ns pulse interval, the 3D micro-electrode was applied in micro-EDM and 3D micro-cavity mold with high surface quality was obtained. Thirdly, in order to reduce the adverse impact of electrode wear on machining precision of 3D micro-cavity mold, 3D queue micro-electrode was used to process the same 3D micro-cavity mold, in which the first electrode is for rough machining and the others for fine machining. Finally, based on the above studies, two kinds of 3D queue micro-electrodes were fabricated, and the 3D micro-cavity molds with surface roughness Ra?=?0.48 μm were obtained through micro-EDM. Compared with the scanning 3D micro-EDM process, the 3D micro-cavity mold can be obtained through up and down reciprocating method of the 3D queue micro-electrode, featuring simple machining process and high efficiency.     

大规模地下空间在线展示关键技术

简述了通过网页3D来分享信息及进行3D交互的相关技术。针对大规模的地下空间场景以及对该场景进行网页实时展示的需求,提出了一套基于互联网进行大规模地下空间实时展示的轻量级场景管理机制。首先,对地下空间场景数据进行轻量化预处理,构建轻量级场景管理结构。然后,根据场景数据特点提出相应的场景管理策略,即基于兴趣区域的室外场景管理策略和基于入口的室内场景管理策略。通过视点位置驱动实现室内外场景切换,并自动选择管理策略,达到在网页上进行远程实时漫游大规模地下空间场景的效果。实验表明:该方法能大幅度剔除不必要的场景数据,提高资源利用率,满足在线展示大规模地下空间场景的需求。由于网页应用具有跨平台优势,提出的系统支持用户跨平台对大规模地下空间场景进行实时漫游与操控。     

电解加工在微细制造技术中的应用研究

电解加工是利用阳极金属电化学溶解原理来去除材料的制造技术,这种微去除方式使得电解具有微细加工的可能,这里着重探讨了高频窄脉冲微细电解加工技术、电液束微细电解加工技术和利用电解制备微细电极的工作原理,技术特点,应用领域和加工精度,并详细的讨论了目前微细电解加工脉冲电源和加工设备的研制和发展。     

复合材料传动轴设计及制造关键技术的研究

总结了复合材料传动轴的轴管典型结构、材料、纤维角度及铺层、接头连接的设计关键技术及纤维复材传动轴、纤维金属混杂复材传动轴的制造关键技术,最后对复合材料传动轴的设计及制造技术的进一步研究方向进行了展望。     

Additive fabrication technologies applied to medicine and health care: a review

Additive fabrication (AF) and rapid prototyping (RP) technologies are mostly associated with applications in the product development and the design process as well as with small batch manufacturing. Due to their relatively high speed and flexibility, however, they have also been employed in various non-manufacturing applications. A field that attracts increasingly more attention by the scientific community is related to the application of AF technologies in medicine and health care. The associated research is focused both on the development of specifically modified or new methods and systems based on AF principles, as well as on the applications of existing systems assisting health care services. In this paper, representative case studies and research efforts from the field of AF medical applications are presented and discussed in detail. The case studies included cover applications like the fabrication of custom implants and scaffolds for rehabilitation, models for pre-operating surgical planning, anatomical models for the mechanical testing and investigation of human bones or of new medical techniques, drug delivery devices fabrication, as well as the development of new AF techniques specifically designed for medical applications.     

An online defects inspection method for float glass fabrication based on machine vision

Quality control is a crucial issue in a float glass factory, and defects existing in float glass can dramatically depress glass grade. Manual inspection in float glass quality control cannot catch up with the development of float glass industry, and automatic glass defect inspection has been a trend. An online defects inspection method for float glass based on machine vision is presented in this paper, and a distributed online defect inspection system for float glass fabrication is realized. This method inspects defects through detecting the change of image gray levels caused by the difference in optic character between glass and defects. A series of image processing algorithms are set up around the analysis of glass image and the requirements of online inspection system such as reliability, real-time, and veracity. Image filtration based on gradient direction is used to filter noise and reserve the source information of defects. Downward threshold based on adaptive surface removes the background composed with stripes and strengthens defect features. Distortion part and core part of defects are obtained through fixed threshold and OTSU algorithms with gray range restricted, respectively. The fake defects (insects, dust, etc.) are eliminated based on the texture of real defects. The application of an inspection system based on this method in Wuhan glass factory proves this inspection method is effective, accurate, and reliable.     

高精度衍射光栅刻划机的最新技术进展

采用高精度的衍射光栅刻划机刻划依然是制作高质量母光栅最重要的手段,因此,跟踪世界光栅刻划机的最新技术进展具有重要的现实意义。文中主要对工件台的双重定位技术和分度运动中的间歇式与连续式的技术融合进行了阐述,并指出了衍射光栅刻划机的发展趋势。     

旋转轴状态参数在线监测技术研究

旋转轴是装甲装备传动系统的重要部件,而扭矩和转速是旋转轴工作中重要的状态参数,对扭矩与转速的测量对衡量发动机输出功率和评估传动系统工作状况具有重要意义。旋转轴运动状态特殊、工作环境复杂,实现对旋转轴的在线监测具有一定困难。在文献调研分析的基础上,针对以上问题,综述了几种旋转轴状态参数的监测技术,分析对比了各种技术的优缺点,对实现装甲装备传动轴在线监测具有较强的指导意义。     

State-of-the-art of polymer tribology

Along with the extensive application of polymers for tribological purposes, the understanding of polymer tribology is becoming increasingly important. A broad overview of the general area of polymer tribology is presented in this paper. The progress in understanding the field over the past decade is reviewed under the three topics of rubber tribology, plastic tribology and tribology of polymer composites. It is hoped that this paper will serve as a valuable source of reference for future tribologists.