激光与熔融石英作用的温度累积研究

基于傅里叶热传导方程, 利用有限差分法计算了石英在激光作用下的温度场分布。结果表明在连续激光的作用下, 石英的轴向温度变化分为升温过程和降温过程。考虑热累积效应, 辐照0.1、0.5、0.8 s后温度较之前分别升高了约 10、100、200 ℃, 激光作用时间越长, 温度累积越明显。对于脉宽为5 ms, 占空比为1/2和1/3的脉冲激光, 辐照3个脉冲后, 温度分别升高94 ℃和82 ℃。石英在轴向方向的温度累积较径向更明显。研究激光与石英相互作用后温度场的分布对激光加工工艺有着重要的意义。     

生物刻蚀金属制作微小三维结构

生物去除法是利用微生物代谢过程中一些复杂的生化反应来达到去除多余材料，加工出其它微细加工方法不能加工出的微小结构。阐述了用氧化亚铁硫杆菌作为生物氧化剂，刻蚀以铜及铜合金为材料的基片表面，得到精细三维结构的原理和方法，并总结了这种新型加工方法的一些优缺点。为了改善生物刻蚀的三维结构的质量，在提高其加工精度及生物加工机理方面正进行着更深入的研究。     

An intelligent process planning system for micro turn-mill parts

An attempt has been made to develop a generalised system for the generation of process plan for the manufacture of micro parts in this work. It has two components; first one deals with automatic part feature extraction from feature-based model and second one performs the execution of process planning activities in accordance with feature using knowledge-based system approach. The proposed system maps extensible markup language (XML) data for the feature based-model and produces the corresponding manufacturing activities needed for the manufacture of micro parts. The process plan modules considered in this work includes process sequence, tools and fixtures, process parameters selection and set-up plan generation. An attempt has been made to develop process parameters selection module based on experimental investigation and optimisation apart from manufacturing catalogues and user manuals. Feature extraction through XML files avoids complex feature extraction process. The application of the developed system has been verified with a case study. The present system is limited to micro turn-mill features. Incorporation of more micro features and consideration of other activities of process plan ensures a complete process planning system for micro-machining processes.     

聚苯乙烯/Al双介质调制靶的研制

介绍了用于流体力学不稳定性实验的聚苯乙烯（CH）/Al双介质调制靶的制备方法。采用激光微加工工艺在50 μm厚Al箔表面制备了调制周期为55 μm、峰谷差为4.7 μm的调制图形;采用旋涂工艺在Al箔表面制备了20 μm厚CH薄膜,经过后期的微切割、微装配工艺,得到了宽度为200 μm、总厚度为70 μm的CH/Al双介质调制靶。该靶型于2010年在“神光-Ⅱ”激光装置中进行了流体力学不稳定性实验。     

摩擦副表面微结构及其超声复合电加工技术研究

设计了圆形、正方形及菱形三种截面形状微结构;用微细电加工技术组合制作了微结构加工工具;构造、完善了超声复合微细电加工系统;进行了微结构超声复合电加工试验,并分析了其加工的工艺特性。进行了摩擦学特性试验,结果表明,具有规则形貌微结构的摩擦副表面摩擦因数及磨损量均减小,研究成果对提高重要摩擦副的使用性能与寿命具有理论意义和工程应用价值。      

Anode Shape Prediction in Through-Mask-Ecmm using Fem

Recent technological developments require advanced manufacturing technologies for miniaturized and micro-scale components in various types of industrial products, e.g., fuel injection nozzle for automobiles, miniaturized medical tools, microprobes used to measure surface properties, integrated micro-channels used for drug delivery systems, micro-gears, and various aeronautical components. Through-mask electrochemical micromachining (TM-ECMM) is a feasible process for such products. In the present work, the finite elements method (FEM) is used for solving 2-D Laplace equation in the inter electrode gap to determine the potential and flux distribution for the anode shape prediction in TM-ECMM. Algorithm has been developed and implemented in MATLAB to estimate surface erosion of anode for finite time steps. Anode shape and undercut are predicted using FEM and compared with the experimental results. The shape evolution through finite element simulation is approximately complying with the experimental anode profile. This work would later help in tool (cathode) design for TM-ECMM.     

超声复合微细电火花加工机理与试验

微结构电火花加工短路、断路或电弧放电作用,降低加工效率及精度。提出将超声频振动与微细电火花加工复合,利用电极与工件之间的超声频相对运动,产生规则的、参数可控的微细脉冲放电;构造、完善超声复合微细电火花试验系统,进行微结构超声复合电火花加工试验,有效避免短路、断路及电弧脉冲,有效提高加工精度与效率。TG662     

微细孔电解加工控制方法及试验研究

基于微细电解加工的特点，介绍了一种微细电解加工系统。该系统能够将加工间隙控制到几微米到几十微米的范围内。根据电解加工以离子形式对材料去除的特性，进行微细电极、微细群电极的制备研究，并将其用于微细孔、群孔的加工中。试验分析了各工艺参数如电压、溶液浓度、加工间隙、进给速度等对微细孔电解加工精度的影响。结果表明，微细电解加工的侧面间隙随着加工电压的降低、溶液浓度的减小、脉宽变窄和初始加工间隙的减小而减小，改善了加工的定域性，加工精度得到提高。     

微细电解线切割加工的基础研究

基于电化学原理，讨论了纳秒脉冲电流微细电解线切割加工的机理，建立了微细电解线切割加工数学模型；采用电化学腐蚀原理对微米尺度线电极进行在线制作，建立了微细电解线切割加工试验系统，并进行了微细电解线切割加工试验，切割出带90°直角的微结构，其切缝宽度为30μm。