磁力液力旋流器在电火花加工工作液处理装置中的应用研究

针对普通电火花加工和混粉电火花加工工作液分离处理过程的现状和存在问题，提出将磁力液力旋流器用于电火花加工工作液中加工渣的分离处理过程，从而提高电火花加工的精度和效率。     

高速走丝电火花超高厚度切割工作液的研制

阐述了高速走丝电火花线切割超高厚度切割的基本条件，分析了目前市场上通用的工作液在超高厚度切割方面存在的问题，由此提出可进行超高厚度切割工作液的基本要求，并成功研制出超高厚度切割工作液，加工中表明其体现出与现有工作液不同的加工工艺特性。     

中走丝电火花线切割工作液的应用与发展

介绍了电火花线切割加工工艺的发展方向,分析了中走丝电火花线切割工作液的性能要求以及对加工的影响,指出了中走丝电火花线切割工作液发展与应用,对目前使用的典型工作液进行了评价。     

模具的复合工作液电火花镜面加工

模具的复合工作液电火花镜面加工用日本三菱电机公司开发的ＶＰ３５Ｆ型电火花成形加工机床，在工作液（油）中加入粉末状的硅，可实现电火花镜面加工。这是三菱电机公司首创的新型加工方法。ＶＰ３５Ｆ和ＶＰ５５Ｆ的基本参数列于附表中。该法的加工原理如图１所示。传统...     

电导率对电火花小孔加工速度影响的研究

从影响电火花小孔加工速度因素分析入手,研究了改变工作液电导率,从而改变了放电间隙,优化了排屑条件,促使电火花加工速度提高的理论。通过不同添加剂改变工作液电导率进行电火花小孔加工实验,与原有自来水工作液加工速度进行对比,发现工作液电导率与小孔加工速度有一定关系,存在工作液最佳电导率范围,所得结论对电火花小孔加工工作液配比有一定参考。     

新型电火花混粉镜面加工液处理工艺流程及装置的设计

提出将磁力液力旋流器用于电火花加工工作液中加工渣的分离处理,分析了国内外普通电火花加工和混有导电性粉末物质的电火花加工分离处理过程的现状和存在问题,介绍了新型电火花加工工作液工艺流程及处理装置的特点和结构设计。     

电火花成形机床工作液循环系统自动控制技术

通过分析电火花成形加工对工作液循环系统的液位、液温、冲抽液压力和工作液洁净度的控制要求,认为电火花成形加工过程中应根据加工工况适时调整工作液泵的压力和流量。根据工作液泵的结构特点和工作特性,认为采用电机变频控制方法来调整工作液泵的流量和压力是一种节能、降噪和延长工作液泵使用寿命的良好方法。在此基础上,提出一种工作液泵频率可控的电火花成形机床工作液循环自动控制系统,该系统由计算机控制,可根据液位、液温、液压和加工状态适时调整工作液泵电机的频率,从而改变工作液泵的输出流量和压力,实现进、冲、抽液的自动切换。该系统不仅节能降噪,还实现了工作液循环系统的自动控制。     

电火花线切割工作液的研究现状

以加工黄铜材料为例,提出了电火花线切割工作液在加工低熔点、较薄材料时存在的问题。详细分析了国内电火花线切割工作液的研究现状,进而提出了研究电火花线切割工作液亟需解决的问题。     

含添加剂的电火花成型加工工作液

含添加剂的电火花成型加工工作液华南理工大学全燕鸣一、概况电火花成型加工在液体介质中进行。工作液主要起介电作用、放电作用、流体动力作用和冷却作用，此外还影响电极表面的覆盖效应及工件表面层的组织和性能。工作液应具备的基本条件是：介电强度高；粘度低，流。动...     

关于电火花加工过程中油类工作液的成分

油类工作液,如煤油、柴油、变压器油等,是电火花加工长期以来使用的工作液。这类工作液虽然存在着易燃和挥发、分解,以及对皮肤有刺激作用等缺点,但由于加工性能较好,因而仍获得广泛使用。在线切割电火花加工中为克服油类工作液的缺点,很早就改用水质工作液。如去离子水、蒸馏水、水包油型乳化液。然而对成型电火花加工来说,水质工作液在绝缘性和加工性能等方面坯不能很好满足要求。目前尚处于研究开发阶段,因此,一时还难以普遍推广使用。国外从七十年代后期以来,对工作液的     

Improvement of Dry EDM Characteristics Using Piezoelectric Actuator

This paper describes improvement of the machining characteristics of dry electrical discharge machining (dry EDM) by controlling the discharge gap distance using a piezoelectric actuator. Dry EDM is a new process characterized by small tool electrode wear, negligible damage generated on the machined surface, and significantly high material removal rate especially when oxygen gas is used. However, the narrow discharge gap length compared with conventional EDM using oil as the dielectric working fluid results in frequent occurrence of short circuiting which lowers material removal rate. A piezoelectric actuator with high frequency response was thus introduced to help control gap length of the EDM machine. To elucidate the effects of the piezoelectric actuator, an EDM performance simulator was newly developed to evaluate the machining stability and material removal rate of dry EDM.     

Near dry electrical discharge machining

This study investigates the near dry electrical discharge machining (EDM) process. Near dry EDM uses liquid–gas mixture as the two phase dielectric fluid and has the benefit to tailor the concentration of liquid and properties of dielectric medium to meet desired performance targets. A dispenser for minimum quantity lubrication (MQL) is utilized to supply a minute amount of liquid droplets at a controlled rate to the gap between the workpiece and electrode. Wire EDM cutting and EDM drilling are investigated under the wet, dry, and near dry conditions. The mixture of water and air is the dielectric fluid used for near dry EDM in this study. Near dry EDM shows advantages over the dry EDM in higher material removal rate (MRR), sharper cutting edge, and less debris deposition. Compared to wet EDM, near dry EDM has higher material removal rate at low discharge energy and generates a smaller gap distance. However, near dry EDM places a higher thermal load on the electrode, which leads to wire breakage in wire EDM and increases electrode wear in EDM drilling. A mathematical model, assuming that the gap distance consists of the discharge distance and material removal depth, was developed to quantitatively correlate the water–air mixture's dielectric strength and viscosity to the gap distance.     

Electrical Discharge Surface Alloying of Ti and Fe Workpiece Materials Using Refractory Powder Compact Electrodes and Cu Wire

The paper reviews the use of metal powders dispersed in the dielectric fluid and refractory PM electrodes, to initiate workpiece surface modification during EDM. Experimental work details the effects of EDM parameters (up to 270 V) on the hardness/composition of the white layer following die sink machining of AISI H13 tool steel and roll texturing of 2% Cr steel using partially sintered PM electrodes. Similar data are presented following EDM scanning and wire cutting of standard TI alloy TI-6AI-4V and a y TIAI. With AISI H13, recast layers were 5-20 μm thick and up to ∼ 1350 HK_0.025. When machining TI-6AI-4V with WC/Co electrodes, recast microhardness was 600-2900 HK_0.025. Wire cutting y TIAI generated porous alloyed layers up to 115 μm thick with extensive cracks and no increase in bulk hardness.     

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.     

混粉电火花加工表面显微裂纹的研究

对混粉电火花加工表面的显微裂纹进行了研究.选用铝粉工作液和硅粉工作液,在不同的参数条件下对两种工件材料进行了加工实验,得到了相应的裂纹分布图.结果表明,脉冲宽度对加工后表面显微裂纹的影响十分明显,峰值电流、粉末种类、工件材料等因素对显微裂纹的影响则并不明显.     

电火花加工放电介质的研究

通过对电火花加工放电通道中等离子体柱的形状和放电通道的电流、电磁特性进行分析,并对电火花加工中不同介质的加工性能进行对比和总结,提出电火花加工介质的技术研究方向应符合绿色制造和资源的可持续发展的理念。     

放电诱导雾化烧蚀深型孔加工技术研究

为提高常规电火花深型孔加工的稳定性及工艺指标,提出了一种新的深型孔加工方法——放电诱导雾化烧蚀加工技术。采用"水基-氧气"高压气雾介质作为放电介质,对烧蚀燃烧反应具有冷却、抑制和分散放电作用,有效降低了烧蚀能量,保证了加工的平稳性。另外,放电间隙中分散的熔融金属与气雾介质的氧气继续充分燃烧,气雾介质吸收释放的能量而迅速气化,产生的爆炸效果对蚀除产物的排出有巨大的促进作用,蚀除产物呈现喷发式排出。因此,放电诱导雾化烧蚀深型孔加工技术不断引入了新的能量,并解决了排屑的难题。在本试验条件下,对于边长为4.4mm的方孔,加工深度可达70 mm以上,材料蚀除率约为内冲液电火花加工的5.45倍,电极质量相对损耗降低了82%。     

Fabrication of deep micro-holes in reaction-bonded SiC by ultrasonic cavitation assisted micro-EDM

Ultrasonic vibration was applied to dielectric fluid by a probe-type vibrator to assist micro electrical discharge machining of deep micro-holes in ceramic materials. Changes of machined hole depth, hole geometry, surface topography, machining stability and tool material deposition under various machining conditions were investigated. Results show that ultrasonic vibration not only induces stirring effect, but also causes cloud cavitation effect which is helpful for removing debris and preventing tool material deposition on machined surface. The machining characteristics are strongly affected by the vibration amplitude, and the best machining performance is obtained when carbon nanofibers are added into the vibrated dielectric fluid. As test pieces, micro-holes having 10 μm level diameters and high aspect ratios (>20) were successfully fabricated on reaction-bonded silicon carbide in a few minutes. The hybrid EDM process combining ultrasonic cavitation and carbon nanofiber addition is demonstrated to be useful for fabricating microstructures on hard brittle ceramic materials.     

混粉电火花加工工作液流场及颗粒运动仿真研究

根据混粉电火花加工对装置的要求,在对储液箱内的粉末颗粒运动状态进行数学分析的基础上,采用COSMOS/Flo Works软件对工作液流场及颗粒运动状态进行模拟仿真.分析结果表明,设计的数学模型能反映储液箱内液流的实际运动状态,并能帮助对射流器喷液结构进行优化设计,该数学模型可为混粉电火花加工装置一体化设计提供技术支持.     

Investigation of the effects of electrode orientation and fluid flow rate in near-dry EDM milling

This research investigates the effects of electrode lead and tilt angles and dielectric fluid flow rate on material removal rate, tool electrode wear ratio, and surface roughness in near-dry electrical discharge machining (EDM) milling process. Computational fluid dynamics (CFD) model is developed to predict the dielectric fluid flow rate and qualitatively compare with the experimentally measured EDM material removal rate. The optimum lead angle, which maximized material removal rate and minimized tool electrode wear ratio, was found. The decrease in the lead angle has a negative effect on the roughness of machined surface. The increase in tilt angle reduces the material removal rate and increases the tool electrode wear ratio. The change in tilt angle does not have a significant effect on the surface roughness and can be used to prevent gouging in finishing EDM milling. This study shows that the material removal rate is linearly proportional to the mass flow rate of air and kerosene mixture, the tool electrode wear ratio is inversely related to the mass flow rate of air and kerosene mixture, and the average surface roughness does not have a good correlation with the flow rate of the mixture.