微热管内壁微结构电化学加工机床控制系统

内表面具有大量非连续强化传热微结构的微热管,因传热性能突出而成为新型微电子器件散热的关键零件。针对微热管内表面非连续微结构加工中的技术难题,提出基于变截面多线螺旋电极的微细电解加工新方法,并自主研制了一台利用Lab VIEW进行运动控制的微细电解加工机床。介绍了机床的结构、原理、控制系统硬件设计和软件设计。该微细电解加工机床可实现套筒类金属零件的内表面微结构低成本、高效率、高表面质量的电解加工成型。     

超声电解复合微细加工装置与试验研究

分析微细电解复合超声频振动加工过程机理,提出一种微细加工新方法--超声电解复合微细加工;设计、构造并完善复合微细加工装置;研究微细阴极制作工艺,利用微细组合电加工技术制作各类截面形状的微细阴极;进行超声电解复合微细加工试验,验证微细电解复合超声频振动实现微细加工的可行性及其在加工速度、精度、表面质量等方面的技术优势,探讨超声电解复合微细加工制作微结构的工艺规律。     

内壁表面微结构加工技术的发展与应用

针对现有的内壁表面微结构加工方法进行论述,分析了各种工艺方法的优点及其存在的问题,对内壁表面微结构的应用进行了简要说明。在此基础上提出了用微细电解加工技术对微管内壁表面进行微结构加工,并且分析了内壁表面微结构的发展趋势。     

高频窄脉冲电流微细电解加工

微细电解加工是微细加工领域很有发展前景的微细加工技术之一。适合于微细电解加工的装置被研制出来, 它包括机床进给机构、线电极电火花磨削在线制作微细电极装置、短路检测模块、脉冲电源及其他一些辅助装置, 其中,高频窄脉冲电源是微细电解加工最重要的核心技术之一。根据微细电解加工的特点,设计了微细电解加工 MOSFET脉冲电源,该微能脉冲电源能很好地满足微细电解加工的要求。运用该微细电解加工装置进行加工试验, 在低的加工电压和低的钝化电解液浓度条件下,利用高速旋转的微细电极加工微小孔和像小铣刀一样进行微细电解铣削加工微结构,得到了满意的工艺效果,因而进一步说明电解加工在微细加工领域很有发展潜力。     

纳秒脉冲微细电化学加工的理论及试验

根据电化学反应原理,探讨纳秒脉冲电化学加工的特点及其实现微细加工的机理.建立纳秒脉冲微细电化学加工的理论模型,并分析电解液浓度、加工间隙、脉冲参数和加工电压等因素对微细电解加工的影响作用.构建微细电化学加工系统,包括微细加工机床、纳秒脉冲电源、电解液循环系统、运动控制部分和加工检测部分.试验研究了超短脉冲的电压幅值和脉冲宽度对侧面加工间隙的影响,结果表明减小脉冲宽度和降低加工电压可以提高微细电解加工的精度.在自制的微细电化学机床上,实现工具电极和工件微结构的连续加工.将加工间隙控制在5 μm以内,加工出中间有20 μm×30 μm×30 μm棱台的微型腔和30 μm槽宽的十字形孔,分析加工起始点对成形精度的影响,并提出解决方法.试验证明纳秒脉冲微细电解加工可以很好地满足微机电系统(Micro electromechanical system,MEMS)微器件的加工要求.     

基于线电极原位制作的微细电解线切割加工

微细电解线切割加工是一种微细加工新方法。从理论上分析了线电极直径大小对微细电解线切割加工精度的影响,提出了原位制作微米尺度线电极的方法,并制作出直径5μm的钨丝线电极。通过电解线切割加工试验,加工出缝宽为20μm左右的微型桨叶结构和曲率半径在1μm以下的微细尖角结构。     

气膜屏蔽微细电解加工方法研究

为实现金属表面微结构高精度、高效率、稳定加工,结合微细电解加工技术和气膜保护原理,提出了一种新的加工方法——气膜屏蔽微细电解加工。对气膜屏蔽微细电解加工时气泡产生的分布规律、保护气膜对水跃现象的影响、微凹坑成形形貌进行分析。结果表明,采用相同加工参数下,气膜屏蔽微细电解加工方法相对电化学射流加工方法,加工出的微凹坑表面粗糙度降低了29.4%、深径比增加了85%、杂散腐蚀减少,进一步验证了所提出加工方法的优越性。     

电解复合超声频振动微细加工机理与试验研究

进行了电解复合超声频振动加工微结构的基础试验,分析了微电流电解过程钝化现象,研究了超声频振动冲击波及负压空化作用消除电解钝化作用机理。分析了电解加工方式与超声频振动协调同步方法,设计和构造了微细电解复合压电式超声频振动微细加工系统。利用微细特种加工技术制作各类截面形状、尺寸的微细阴极。进行了多种材料微结构的复合加工试验,并验证了电解复合超声频振动方法实现微细加工可行性与技术优势,研究了应用该工艺进行微结构加工的工艺特性。     

加工轨迹对薄壁件微结构电解铣削的影响北大核心

为改善难加工材料弹性合金3J21薄壁件微结构的成形加工质量和效率,进行了加工轨迹对薄壁件微结构的电解铣削加工的影响研究。首先利用拷贝式电解加工方法在线制备了阶梯轴式微细工具阴极,然后利用5种不同加工轨迹进行了150μm"150μm微型方孔的微细电解铣削加工对比实验,并优选出了最佳的加工轨迹。研究结果表明,利用"行铣+环铣"的加工轨迹进行微细电解铣削加工时微型方孔的加工质量更好,加工效率较高。     

超短脉冲电流微细电解加工技术研究

利用电化学腐蚀方法,在自制的电解加工机床上连续实现微细工具电极的制作和工件的加工,通过试验研究了超短脉冲的电压幅值和脉冲宽度对侧面加工间隙的影响。结果表明,减小脉冲宽度,降低加工电压,可以提高微细电解加工的精度。利用优化的加工参数,进行了微小孔加工、微细直写加工以及成形电极微细加工的实验。     

Precision machining of micro tool electrodes in micro EDM for drilling array micro holes

Micro electro discharge machining (micro EDM) is suitable for machining micro holes on metal alloy materials, and the micro holes can be machined even to several microns by use of wire electro discharge grinding (WEDG) of micro electrodes. However, considering practicability of micro holes <Φ100 μm in batch processing, the controllable accuracy of holes’ diameter, the consistency accuracy of repeated machining and the processing efficiency are required to be systematically improved. On the basis of conventional WEDG method, a tangential feed WEDG (TF-WEDG) method combined with on-line measurement using a charge coupled device (CCD) was proposed for improving on-line machining accuracy of micro electrodes. In TF-WEDG, removal resolution of micro-electrode diameter (the minimum thickness to be removed from micro electrode) is greatly improved by feeding the electrode along the tangential direction of wire-guide arc, and the resolution is further improved by employing negative polarity machining. Taking advantage of the high removal resolution, the precise diameter of micro-electrode can be achieved by the tangential feed of electrode to a certain position after diameter feedback of on-line measurement. Furthermore, a hybrid process was presented by combining the TF-WEDG method and a self-drilled holes method to improve the machining efficiency of micro electrodes. A cyclic alternating process of micro-electrode repeated machining and micro holes’ drilling was implemented for array micro holes with high consistency accuracy. Micro-EDM experiments were carried out for verifying the proposed methods and processes, and the experimental results show that the repeated machining accuracy of micro electrodes was less than 2 μm and the consistency accuracy of array micro holes was ±1.1 μm.     

Efficiency evaluation of micro factory for micro pump manufacture

The micro factory, a miniature manufacturing system, is a means of achieving higher throughput with minimal space, and minimal consumption of energy and resources by downsizing of production processes. Even though, a micro factory is able to perform whole manufacturing processes like the macro factory, the possibility of improving its manufacturing efficiency has not been considered enough. In this paper, an efficiency index is proposed to calculate the efficiency of the micro factory to manufacture a micro pump. The efficiency index has been proposed based on efficiency definition with input and output parameters of the system. Input parameters include cost of system, processing time and energy. Output parameters represent number of product manufactured from the microfactory. Cost of the system has been categorized by micro assembly machine cost, cost of resources, manipulators’ cost, manufacturing space value, and human operators. Processing time has been categorized by assembly time and material handling time. This paper was recommended for publication in revised form by Associate Editor Dae-Eun Kim Murali Subramaniyam received his B.E. and M.Tech. from India in 2003 and 2005, respectively. Currently, he is pursuing his Ph.D. in Me-chanical Design Engineering under Brain Korea 21 program fellowship at CNU (Chungnam National University), Korea. Also he is working as a research associate in LID (Laboratory of Intelligent Design and manufacturing) at CNU, under Professor Sangho Park. His research interests include CAD/CAM (Computer Aided Design/ Computer Aided Manufac-turing), Computer Integrated Manufacturing, Rapid Prototyping and DHM (Digital Human Modeling). Sangho Park is currently a Professor in Mechanical Design Engineering at CNU. He received his B.S., M.S. and Ph.D. from Seoul National University, Korea in 1988, 1990 and 1995 respectively. He was a Senior Research Scientist at ETRI (Electronics and Telecommunications Research Institute), Korea. His areas of expertise and research interest includes CAD/CAM, Virtual Reality, DHM and Micro Assembly. LID (renamed from CAD/CAM) is doing research under his advice. Sung-il Choi received a B.S. form Konyang University in 1995, Korea. He then received an M.S. from CNU in 1997. Currently, he is pursuing his Ph.D. in Mechanical Design Engineering at CNU. He was a researcher at ETRI. His research intersts include the areas of development of CAD interface, virtual simulation, 3D Web solutions, geometric modelling, micro-assembly, and application of distributed environment. Jun-Yeob Song is a Team Leader in the IT Machinery Research Team, Korea Institute of Machinery and Materials, Korea. Also, He is a Chief of National Research Laboratory on Knowledge Evolution based Manufacturing Devices. He received a Ph. D. from the School of Industrial Engineering at Busan National University in 2001. He has extensive experience in design & control of automation and autonomous manufacturing systems, and reliability engineering. In recent years, Dr. Song’s research interests are in the area of micro assembly, bonding, and multi chip packaging (MCP). Jong-Kweon Park received a B.S. degree in Mechanical Engineering from Inha University in 1977. He then received M.S. and Ph.D. degrees in mechanical engineering from Changwon National University in 1993 and 1997. Dr. Park is currently a principal research at Korea Institute of Machinery and Materials in Daejeon, Korea. His current research areas are cutting dynamics and control, structural dynamics and optimization, ultra precision machining systems, micro/nano manufacturing systems, and design and evaluation of machine tool systems. He is currently a project leader for the project, “Development of Microfactory System Technologies for Next Generation.”     

微小型结构件显微图像边缘的自动识别

在前一阶段的研究工作中,针对微小型结构件的显微图像边缘提取,作者提出了一种基于工艺匹配的显微图像边缘提取算法（Micro Processing Technology Matching based Micro Image Edge Detection, MPTM-MIED）。使用MPTM-MIED提取图像边缘之前,需要手工从零件显微图像中选取边缘过渡区域,这一操作将极大影响微小型零件的检测速度,从而使MPTM-MIED不能应用在实时自动检测中。针对MPTM-MIED的这一不足,本文利用BP神经网络技术重新设计并实现了MPTM-MIED,提出了一种新的自动提取显微图像边缘的方法（An Automated Micro Image Edge Detection Method,AMIED）。为了验证该方法的有效性,本文还利用AMIED对4种工艺微小型结构件显微图像的边缘进行了提取,并对线切割工艺零件的尺寸进行了测量。边缘提取的分析结果表明：AMIED提取出的显微图像边缘与MPTM-MIED提取出的基本一致;与常用的边缘检测算法相比,AMIED提取出的显微图像的边缘线形连接程度较好。测量尺寸的分析结果表明：MPTM-MIED和AMIED测量的尺寸基本相同,与Canny测量的相比,更接近万能工具显微镜测得的尺寸。     

金属微粉体脉冲输送的微特性实验

采用以脉冲为微流动基本形态、脉冲当地惯性力为主动力的微流体数字化技术进行了金属微粉体(作为流体)脉冲输送微特性的实验,以解决激光金属粉体融覆沉积工艺中微粉体的精确稳定输送问题.建立了金属微粉体脉冲输送系统;以角形铬粉为实验材料,实验研究了驱动电压U、频率f、微喷嘴内径d、输送角度θ等4种系统参量对铬粉脉冲输送微特性(粉...     

Vibration assisted wire electrochemical micro machining of array micro tools

Micro structures and components are widely used in modern industries, and micro machining has therefore become a popular research topic. As micro tools are essential in micro machining, wire electrochemical micro machining is introduced in the fabrication of micro tools in this paper, and micro square column tool arrays are fabricated using wire cathodes by two steps. In order to improve the machining efficiency and quality, an electrode vibration technique is used, and the effects of bubble behaviour on slit width homogeneity and edge radius are studied through simulations of the electric field. The influences of various machining parameters such as vibration conditions, electrical properties, electrolyte concentration and feedrate on the standard deviation of the slit width and on the value of the edge radius are investigated. In addition, the micro dimple array is fabricated using electrochemical micro machining by employing the micro square column tool array as the cathode.     

5-axis micro milling machine for machining micro parts

This paper presents a PC-based 5-axis micro milling machine, which can be used for machining micro-sized parts, and be easily constructed a low cost. Micro cutting is a method for manufacturing three-dimensional micro parts; however, machine tools for micro machining are expensive. The micro milling machine presented in this paper is mainly composed of commercially available micro stages, and an air spindle and PC-based control board. An effective method for initializing the spindle position is proposed. Test results of the micro milling machine are presented, which include machining of micro walls, micro columns and micro blades.     

Bending strength analysis of micro WC-shaft manufactured by micro electro-discharge machining

Micro electro-discharge machining (micro-EDM) is a critical technology to fabricate high aspect ratio 3D micro-components. However, the surfaces of micro-components manufactured by micro-EDM will exhibit micro-cracks to produce notch effects, and lead to stress concentrate and reduction of fatigue strength. This paper performs micro-bending tests to investigate the influence of various roughness and size on the bending fracture strength of micro WC-shafts manufactured by micro-EDM. The experimental results indicate that the surface roughness, axial surface area, volume, and length of the specimen will affect its bending fracture strength. For specimens with the same size, the mean bending fracture strength decreases as the surface roughness increases, and the bending fracture probability of the specimens also increases (roughness effect). For specimens with the same roughness, reducing the length or axial surface area will increase the mean bending fracture strength, and reduces the bending fracture probability (size effect).     

Manufacture of micro sized threads for micro actuator of laser grating mount

This work presents the fabrication of micro threads of pitch less than 100?μm for micro components. The micro sized threading tool having a tool nose radius less than 40?μm is manufactured by micro wire electric discharge machining (μWEDM) process. This μWEDM process overcomes the difficulties in conventional machining process for production of threading tools and helps in achieving a corner radius as small as 15?μm with specialized wire tool path strategies. This method also helps in fabrication of special micro tools from commercially available or worn-out tungsten carbide tool inserts.     

ICF微靶零件微铣削毛刺实验研究

通过实验的方法研究了微铣削加工过程中切削速度、每齿进给量以及每齿进给量与刀具刃口半径比值对毛刺的影响规律。实验结果表明,顺铣侧产生毛刺比逆铣侧产生毛刺尺寸大。每齿进给量相对于切削速度对毛刺的高度和厚度有显著的影响,且随着每齿进给量的增大,毛刺的高度和厚度也随之增大。当使用小进给量时,毛刺高度和厚度随切削速度提高而减小,当使用大进给量时,毛刺高度和厚度随切削速度的提高而增大。     

Fabrication of various shaped tungsten micro pin arrays using micro carving technology

This paper describes a state of the art in micro-structuring high strength metallic materials. Tungsten micro pin arrays in a variety of shapes are fabricated using a micro carving technology, which combines laser beam machining and electrochemical etching processes. First, micro pin arrays were rough-shaped by laser beam machining along a pre-defined scanning path to control their structural shape. The micro pin array in this stage had near-conical shape of structures due to a recast layer. Next, the genuine shape of micro pin arrays came to the surface via electrochemical etching process to elute the recast layer into electrolyte. Quantitative elemental analysis with energy-dispersive spectroscopy (EDS) was implemented to characterize the formation of recast layer on a micro pin structure after the laser beam machining process. The atomic percentage EDS maps indicated that higher percentage of tungsten was detected on the core micro pin structure, whereas relatively large percentage of oxygen was found on the recast layer (O 9%, W 91% in the center area, and O 53%, W 47% in the outer area).