Abstract The prediction of surface topography obtained with electrical discharge texturing (EDT) process is very challenging, due to stochastic nature and complex physics in occurrence of sparks. Though there are a few models for surface texture prediction in the literature, there are still ample opportunities to improve upon by adopting more realistic assumptions and formulations for simulation. This paper presents a numerical simulation of progressive development of surface topography due to sequential application of spark discharges on an instantaneous textured surface formed by all previous spark discharges. The model incorporates major single-spark features such as, Gaussian distribution of heat flux, temperature-dependent work material properties, latent heat of melting, and operating parameter dependent variation of factors such as, cathode energy fraction, spark radius, and plasma flushing efficiency; besides the multi-spark features such as, stochastic distribution of sparks with respect to: i) location, ii) energy level, and iii) chronological order. Finite element simulation of EDT is performed in ABAQUS with the help of user-defined subroutines for the dynamic simulation of spark discharges, flagging of elements attaining evaporation temperature from further heat flux application and storage of the highest temperatures attained by each element. An evolution of surface texture through the progress of spark erosions has been studied. As EDT continues, the number of craters overlapping generally tend to increase, whereas the center-to-center distance between a crater with its nearest neighbour tends to decrease. The simulated surface textures are validated with the experimental ones using two methods: error function method and Ra distribution method, and were found to be in good agreement.

中文翻译：

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考虑多放电现象的放电纹理表面形貌预测的有限元模型

摘要 由于火花发生的随机性和复杂的物理特性，通过放电纹理化 (EDT) 工艺获得的表面形貌预测非常具有挑战性。尽管文献中有一些用于表面纹理预测的模型，但通过采用更现实的假设和公式进行模拟，仍有很多改进的机会。本文介绍了由于在所有先前火花放电形成的瞬时纹理表面上连续应用火花放电而导致的表面形貌逐渐发展的数值模拟。该模型结合了主要的单火花特征，例如热通量的高斯分布、与温度相关的工作材料特性、熔化潜热以及与运行参数相关的因素变化，例如，阴极能量分数、火花半径和等离子体冲洗效率；除了多火花特征，例如火花的随机分布：i) 位置，ii) 能量水平，和 iii) 时间顺序。EDT 的有限元模拟是在用户定义的子程序的帮助下在 ABAQUS 中执行的，用于火花放电的动态模拟，标记元素从进一步的热通量应用中达到蒸发温度，并存储每个元素达到的最高温度。已经研究了通过电火花腐蚀的进展表面纹理的演变。随着 EDT 的继续，重叠的陨石坑的数量通常会增加，而与其最近相邻的陨石坑之间的中心距往往会减少。