Study of the recast layer of a surface machined by sinking electrical discharge machining using water-in-oil emulsion as dielectric
Study of the recast layer of a surface machined by sinking electrical discharge machining using water-in-oil emulsion as dielectric
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DOI：
10.1016/j.apsusc.2011.01.083
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发表时间：
2011-05
影响因子：
6.7
通讯作者：
Yanzhen Zhang;Yonghong Liu;R. Ji;Bao-ping Cai
中科院分区：
文献类型：
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作者：
Yanzhen Zhang;Yonghong Liu;R. Ji;Bao-ping Cai
电火花加工（EDM）导致重铸层形成在工件的加工表面。重铸层的特性与电介质的类型有很大关系。本文的研究工作旨在深入了解以油包水（W/O）乳化液为介质的电火花加工表面的重铸层。采用扫描电子显微镜（SEM）、X射线衍射仪（XRD）、能谱仪（EDS）和显微硬度分析等手段对试样进行了分析。通过与煤油和去离子水介质中重铸层的对比，研究了W/O乳状液中重铸层的特性。结果表明，与煤油和去离子水相比，W/O乳化液中形成的重铸层具有更大的表面粗糙度、厚度和显微硬度。在W/O乳状液中形成的重铸层中检测到碳化物和氧化物，而在煤油中形成的重铸层中仅检测到碳化物。由于熔融材料中气体的过饱和度较高，W/O乳状液中形成的重铸层比煤油和去离子水中形成的重铸层具有更多的微孔。
Electrical discharge machining (EDM) caused a recast layer to form at the machined surface of the workpiece. The characteristics of the recast layer have a great relationship with the type of dielectric. The research work in this paper aims to acquire a profound knowledge of the recast layers of a surface machined by sinking EDM using water-in-oil (W/O) emulsion as dielectric. Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrograph (EDS) and micro hardness analysis were performed. The characteristics of the recast layer formed in W/O emulsion were investigated by comparing them with those of the recast layer formed in kerosene and de-ionized water dielectric. It was found that the recast layer formed in W/O emulsion exhibited larger surface roughness, thickness and micro hardness compared with that formed in kerosene and de-ionized water. Both carbide and oxide were detected in the recast layer formed in W/O emulsion whereas only carbide was detected in the recast layer formed in kerosene. Due to the higher supersaturation of gases in the melted material, the recast layer formed in W/O emulsion was found to possess more micro-voids than that formed in kerosene and de-ionized water.