共查询到18条相似文献,搜索用时 156 毫秒
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为从微观角度研究电火花加工蚀除机制,利用分子动力学方法,基于改进的能量输入方式,采用膨胀的高斯热源模型模拟电火花加工中放电通道的热作用,对微细电火花加工放电凹坑的形成过程和由熔融再凝固层及热影响层组成的表面变质层特性进行了仿真研究。 相似文献
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电火花加工的放电蚀除过程是在极短时间内和极微小空间内发生的,导致用观测和理论分析的方法进行研究都极其困难,因此其放电蚀除机理至今仍未能被明确的解释.论文应用分子动力学方法对微细电火花加工的放电蚀除过程和熔融区的形成及形状等进行了模拟研究,该研究基于放电通道变化的热源模型,并与放电通道恒定情况下的模拟结果进行了对比,证明... 相似文献
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P. Govindan Suhas S. Joshi 《International Journal of Machine Tools and Manufacture》2010,50(5):431-443
Dry electrical discharge machining is one of the novel EDM variants, which uses gas as dielectric fluid. Experimental characterization of material removal in dry electrical discharge drilling technique is presented in this paper. It is based on six-factor, three-level experiment using L27 orthogonal array. All the experiments were performed in a ‘quasi-explosion’ mode by controlling pulse ‘off-time’ so as to maximize the material removal rate (MRR). Furthermore, an enclosure was provided around the electrodes with the aim to create a back pressure thereby restricting expansion of the plasma in the dry EDM process. The main response variables analyzed in this work were MRR, tool wear rate (TWR), oversize and compositional variation across the machined cross-sections. Statistical analysis of the results show that discharge current (I), gap voltage (V) and rotational speed (N) significantly influence MRR. TWR was found close to zero in most of the experiments. A predominant deposition of melted and eroded work material on the electrode surface instead of tool wear was evident. Compositional variation in the machined surface has been analyzed using EDAX; it showed migration of tool and shielding material into the work material. The study also analyzed erosion characteristics of a single-discharge in the dry EDM process vis-á-vis the conventional liquid dielectric EDM. It was observed that at low discharge energies, single-discharge in dry EDM could give larger MRR and crater radius as compared to that of the conventional liquid dielectric EDM. 相似文献
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目的 分析液相脉冲放电微观机理,解释放电过程中放电通道对电极的影响。 方法 以 45 钢表面液相脉冲放电沉积 TiC 陶瓷涂层放电沉积瞬间极板间形成的单脉冲等离子体为研究对象,用粒子模拟的方法描述了放电通道中电子、钛离子的运动及分布状态。 结果 放电通道中电子的运动较为活跃,在放电形成的开始阶段,电子由工件电极负极激发,迅速向工具电极移动,期间通过与液相介质中的中性粒子碰撞,迅速往工具电极积累,运动过程中遵循等离子体的集体运动特性,过程贯穿于整个等离子体的形成过程;在相同的时间步长内,放电通道中 Ti 离子的运动比电子要缓慢得多,在脉冲放电期间需要较多的时间才能迁移到极板。 结论 放电镀膜时,所用极间距应大于电火花成形加工时的极间距。 相似文献
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This paper presents an investigation of the hybrid dry EDM process performed in a pulsating magnetic field for improving process performance. In this study, the pulsating magnetic field is applied tangential to the electric field, for increasing the movement of electrons and degree of ionization in the plasma. Experiments with parametric variations showed that this hybrid approach leads to productivity-improvement by 130% and zero tool wear as compared to the dry EDM process without the magnetic field. The improvement in surface quality is illustrated by scanning electron microscopy (SEM). 相似文献
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