信噪比与灰色关联分析连杆衬套强力旋压参数优化研究

强力旋压加工连杆衬套优化过程受多个工艺参数的制约,这也决定了旋压成形的优化是多目标优化。为了目标函数粗糙度和回弹量同时降低,应用正交试验方案,选取了进给比、减薄率、首轮压下量等工艺参数对成形精度目标的影响试验,信噪比结合灰色关联分析方法,将多目标工艺参数优化问题转化为单目标灰色关联优化,获得强力旋压加工成形精度工艺指标要求下的参数优化组合。结果表明,信噪比与灰色关联度相结合的优化方法,有效地降低强力旋压过程的缺陷,提高成品的成形精度。     

玻璃微结构电解电火花铣削加工试验研究

为满足石英玻璃等非导电硬脆材料微结构的加工需求,对微细电解电火花铣削加工工艺进行了深入的试验研究,在玻璃工件上进行了一系列微细电解电火花铣削加工工艺试验。首先,基于电解电火花加工的原理搭建了微细电解电火花铣削试验平台;其次,通过对比试验,研究了加工电压、脉冲频率、占空比和进给速度等工艺参数对铣削槽宽的影响,并通过优化工艺参数加工出微槽阵列;最后,成功加工出多个玻璃微结构包括二维微流道和三维微结构,试验结果表明微细电解电火花铣削工艺在加工非导电硬脆材料微结构方面具有很大潜力。     

超声振动复合微细电火花加工微小孔试验研究

微小孔加工时的放电间隙较小,排屑、消电离状态差,放电效率低,直接影响加工效率和电极损耗;超声振动可改善排屑、消电离状态,能提高放电效率。将超声引入微细电火花加工,通过工件的超声振动,进行超声功率、小孔孔径、脉冲频率的微小孔电火花加工工艺试验研究,结果表明:加工不同孔径时,超声功率及电源频率都存在一个最佳值;加工条件合适时,超声复合微细电火花加工优于常规微细电火花加工。     

基于实验设计的电火花微小孔加工参数优化研究

综合考虑电火花微小孔加工中伺服参数与电参数的影响，采用实验设计的方法对微小孔加工效率进行优化研究。首先以一次正交试验对小孔加工中的微进给速度进行优化，以获得稳定快速的伺服响应，在此基础上进行二次正交试验，采用田口方法确定电参数的最佳水平组合。经参数优化后，小孔加工时间由初始的137．2s缩短到67．9s，加工效率显著提高。     

分流法小孔电火花加工数值模拟及实验

介绍分流法小孔电火花加工数值模拟方法,利用有限元分析软件ANSYS模拟单次脉冲放电温度场和电火花小孔加工放电状态,以等面积分流为原则,分别模拟单电极和双电极小孔电火花加工材料去除过程,分析了材料去除量随时间变化的规律.双电极模拟和试验,获得加工过程稳定且小于单电极临界加工尺寸的小孔.选用紫铜工具电极、奥氏体不锈钢工件进行验证实验,仿真结果与实验验证结果相符,为微小孔电火花加工提供了应用依据.     

三维微细电火花加工精密运动系统的设计研究

提出一种新的、可用于多种微细加工的、低速、多自由度并具有纳米精度的三维极微细电火花加工系统.初步构建出极微细电火花加工机电系统功能模块,实现极微细电火花三维加工过程的监测与控制;优化加工系统的控制和基本的工艺参数设置;达到纳米级电火花加工的关键技术途径.     

小孔分流法电火花加工的分流状态研究

介绍一种小孔电火花分流加工新方法,建立小孔的电火花分流加工的分流模型,检测研究加工过程分流状态,得出每个分电极通过的电流按基尔霍夫定律减小,从而分流放电电流和减小放电蚀除体积.在研究条件范围内,进一步对分流法电火花加工过程的分流状态检测,得到多个分电极同时形成放电火花,说明了分流法加工分流作用.研究结果表明,利用电火花机床稳定加工参数,进行等面积分流电火花加工,将加工出比原机床稳定加工临界尺寸更小的小孔,为微小孔电火花加工分流状态的研究和应用提供试验依据.     

基于信噪比和灰色关联度分析的TiC/Ni金属陶瓷电火花加工工艺参数优化

针对Ti C/Ni金属陶瓷电火花加工工艺进行了研究,主要工艺目标为工件材料蚀除率、侧面间隙和表面粗糙度,工艺参数为峰值电流、脉宽、脉间、伺服电压、伺服速度和抬刀周期。在正交试验基础上,采用信噪比分析结合灰色关联度分析方法,研究了各工艺参数对工件材料蚀除率、侧面间隙和表面粗糙度的影响,优选出一组综合多项工艺目标的最优加工工艺参数组合方案。试验验证结果表明,基于信噪比和灰色关联度分析的优化方法能改善Ti C/Ni金属陶瓷电火花加工的效率、精度和质量。     

气中微细电火花沉积加工的单脉冲放电过程热力学仿真(英文)

建立气中微细电火花沉积加工过程电极材料的热物理模型。利用有限元分析软件ANSYS对单脉冲条件下的工具电极和工件的瞬态温度场进行数值模拟,分析热源形式、初始边界条件和放电能量分配对工具电极和工件材料蚀除形式的影响,并预测适合微细电火花沉积加工的工艺参数。采用仿真预测得到的工艺参数,在高速钢工具表面稳定沉积出直径约200μm、高度约1.2mm的微圆柱结构。对沉积材料微观组织结构的测试分析表明,沉积材料与基体结合紧密。工艺实验和测试分析证明了所建立的微细电火花沉积加工过程的单脉冲放电热物理模型和有限元求解过程的正确性。     

微喷部件阵列孔电火花加工工艺试验研究

比较各种微细阵列孔的电火花加工方法,分析了单电极加工微细阵列孔方法的优点。以去离子水作为工作液,在已研制成功的微喷部件阵列孔电火花加工机床上进行单电极加工微细阵列孔的工艺试验,研究电源参数对微细阵列孔的孔径一致性、加工效率及电极损耗的影响规律。优化微细阵列孔加工的电参数,实现稳定的一次性加工256个直径小于50μm、偏差小于2μm的微细阵列孔。     

钢质蜂窝夹芯减振板的实验研究

采用多目标优化方法设计了3种不同规格减振板的面板、芯材以及蜂窝芯尺寸。面板和芯材之间采用自制助复剂,利用瞬间液相扩散焊原理实现复合,并进行了力学性能和减振性能试验,试验结果表明,设计的蜂窝板满足力学性能要求,并提高了减振性能。     

The use of the orthogonal array with grey relational analysis to optimize the electrical discharge machining process with multiple performance characteristics

In this paper a new approach for the optimization of the electrical discharge machining (EDM) process with multiple performance characteristics based on the orthogonal array with the grey relational analysis has been studied. A grey relational grade obtained from the grey relational analysis is used to solve the EDM process with the multiple performance characteristics. Optimal machining parameters can then be determined by the grey relational grade as the performance index. In this study, the machining parameters, namely workpiece polarity, pulse on time, duty factor, open discharge voltage, discharge current, and dielectric fluid are optimized with considerations of multiple performance characteristics including material removal rate, surface roughness, and electrode wear ratio. Experimental results have shown that machining performance in the EDM process can be improved effectively through this approach.     

田口-灰关联法应用于Inconel 718微放电铣削参数最佳化(英文)

应用田口-灰关联法对Inconel 718微放电铣削多重质量特性如电极消耗率、材料去除率和扩口量进行最佳化,分析放电电流、脉冲时间、休止时间和极间间隙对加工Inconel 718之电极消耗率、材料去除率和扩口量的影响。实验结果表明,以最佳微放电铣削参数进行加工,其电极消耗率由5.6×10-9mm3/min降低到5.2×10-9mm3/min,材料去除率由0.47×10-8mm3/min增加到1.68×10-8mm3/min,扩口量由1.27μm降低到1.19μm。研究结果显示,应用田口-灰关联法,可以改善微放电铣削多重质量特性。     

Modelling and Simulation of Micro EDM Process

In micro EDM, simple-shaped tools are being used to machine complex 3D micro features because of the cost and difficulty in fabricating multiple complex-shaped micro electrodes. However, the tool wear adversely affects the accuracy of machined micro features. Therefore, a theoretical model for surface profile generation which takes into account the effect of tool wear is needed. This paper presents such a model and a simplified simulation algorithm. The experimental results of micro and macro EDM generated surface profiles confirm the validity of the proposed mathematical model and the simulation algorithm.     

微细电火花伺服扫描加工实验研究

进行微细电火花三维扫描加工时，由于电极损耗相对严重，导致形位公差难以保证和加工效率较低。该研究分析了电火花加工常规的电极损耗补偿方法，提出了基于放电间隙伺服控制进行电极损耗实时补偿的微细电火花三维扫描加工方法。辅助以电极电接触感知工件平面和加工原点，三维结构加工实验显示，采用间隙伺服控制进行电极损耗实时补偿有利于提高扫描加工微三维结构的形位精度和加工效率。     

High Aspect Ratio and Complex Shaped Blind Micro Holes by Micro EDM

It is difficult to drill high aspect ratio through holes and complex shaped blind holes using micro EDM. The debris concentration in the narrow discharge gap causes abnormal discharges leading to excessive electrode wear and lower machining precision. In micro EDM, the electrode size is too small for internal flushing. This paper presents a new approach for effective self-flushing using planetary movement. Through micro holes with an aspect ratio of 18 have been drilled. This approach is also demonstrated by drilling blind noncircular micro holes with sharp corners and edges. The process performance characteristics are analyzed under different machining conditions.     

EDM drilling of ultra-high aspect ratio micro holes with insulated tools

This work presents an innovative method for the Electrical Discharge Drilling of ultra-high aspect ratio (AR > 30) micro holes. It makes use of tools insulated on the sidewall by means of a coating. The concept is to promote the process stability of micro EDM deep drilling by preventing secondary sparks. The performance of standard and customized tools is compared and reviewed against the main criteria of shape quality, tool wear and machining time. Process capabilities are also defined for a given coating. Micro holes within 0.2 mm in diameter and aspect ratio (AR) up to about 120 could be obtained within 1 h. A micro punching die is also realized by combining this strategy with micro wire EDM.     

我国微小型电火花加工装置最新研究与进展

介绍了我国微小型电火花加工装置的最新研究成果与进展,介绍了多种加工装置的原理、结构和性能,并展望了未来微细电火花加工装置的发展趋势。     

Electrical discharge machining of Ti6Al4V with a bundled electrode

The aim of this study is to investigate an efficient Ti6Al4V electrical discharge machining (EDM) process with a bundled die-sinking electrode. The feasibility of machining Ti6Al4V with a bundled electrode was studied and its effect on EDM performance was compared experimentally using a solid die-sinking electrode. The simulation results explain the high performance of the EDM process with a bundled electrode by through the use of multi-hole inner flushing to efficiently remove molten material from the inter-electrode gap and through the improved ability to apply a higher peak current. A 3-factor, 3-level experimental design was used to study the relationships between 2 machining performance parameters (material removal rate: MRR, tool wear ratio: TWR) and 3 machining parameters (fluid flow rate, peak current and pulse duration). The main effects and influences of the 2-factor interactions of these parameters on the performances of the EDM process with the bundled electrode are discussed.     

基于RTLinux的微细电火花加工软数控系统设计

以三维微细电火花加工为目标，开发基于工控机和RTLinux平台的微细电火花加工软件数控系统。在前期设计的系统平台基础上，利用模块化方法设计了RTLinux内核下的Soft-CNC模块，实现了微细电火花加工数字控制系统由软件完成，并提出了基于双缓冲机制的大数据量传输方法。三维微细电火花加工实验证明了系统的可靠性与实用性。