Current Trends in Electric Discharge Machining Using Micro and Nano Powder Materials- A Review☆
Current Trends in Electric Discharge Machining Using Micro and Nano Powder Materials- A Review☆
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微纳米粉末材料电火花加工的现状回顾☆
DOI：
10.1016/j.matpr.2015.07.147
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
A. Dixit
中科院分区：
文献类型：
--
作者：
R. Bajaj;A. Tiwari;A. Dixit
混粉电火花加工（PMEDM）已经清楚地证明了其优于无添加剂的电火花加工。当受控的尺寸和浓度的金属颗粒混合在电火花加工的电介质中时，它有助于改善各种加工参数，如增加的MRR、降低的表面粗糙度、降低的工具磨损率和改善的拓扑特性，如减少微孔、微孔、薄重铸层和改善的加工表面的耐腐蚀性。因此，近几十年来，PMEDM引起了众多研究者的关注。本文综述了近年来在电火花加工液中添加微纳米粒子进行脉冲电火花加工的一些重要研究工作。在此基础上，本文不仅讨论了微纳米粒子的尺寸和浓度对电火花加工性能的影响，还阐述了微纳米粒子的导热系数、电阻率、密度等因素以及最佳加工参数如峰值电流、脉冲开启时间和脉冲关闭时间等对加工性能的影响。通过文献综述发现，在一定范围内，粉末浓度越高，加工表面质量越好，但当粉末浓度超过最佳值时，工具电极与工件之间会发生短路，从而降低加工表面质量。此外，微米或纳米颗粒通过将电极间隙增加约两倍于没有微米或纳米颗粒的电火花加工，从而实现了更少的热量传递到工件，从而改善了表面光洁度并降低了刀具磨损率。作者还指出了研究差距，以进一步研究的目的。
Powder mixed electric discharge machining (PMEDM) has clearly proven its advantages over EDM without additives. When controlled size and concentration of metal particles are mixed in the dielectric medium of Electrical discharge machining it helps to improve the various machining parameters like increased MRR, reduced surface roughness, reduced tool wear rate and improved topological properties like reduction in microholes, micropores, thin recast layer and improved corrosion resistance of the machined surface. Therefore, PMEDM have attracted the attention of many researchers since last few decade. This paper present a summary of some important research work done on PMEDM by mixing micro and Nano size particle in the dielectric fluid of EDM. Further this review article discuss not only the effect of micro or nano particle size and concentration on the EDM performance but also unfold the other factors like thermal conductivity, electric resistivity and density of micro or nano particles and optimal machine parameters such as peak current, pulse on time andpulse off time which affects the machining performance. From literature review, it has been found that surface finish in PMEDM increases with the decreased particle size and increased powder concentration upto certain limit, but increasing powder concentration beyond the optimal value create short circuit between the tool electrode and workpiece and hence reduces the surface finish. Furthermore micro or nano particles transfer less heat to workpiece by increasing the electrode gap approximately twice as compare to EDM without micro or nano particle, hence improved surface finish and reduced tool wear rate were achieved. Authors have also identified the research gap for further research purpose.