高速电弧放电加工的工艺特性研究

发布时间：2018-11-12 08:57

【摘要】：基于流体动力断弧的高速电弧放电加工(Blasting erosion Arc machining,BEAM)是一种利用高速流场控制电弧放电,高效蚀除工件材料的特种加工新技术。该技术从原理到实现都与传统的电火花放电加工(EDM)有着本质区别。将高能量密度的电弧、具有三维型面的多孔电极、极间的高速工作液流场以及多轴联动进给这四种关键要素的有效结合,实现了一种新型而高效的材料去除加工方法。采用石墨集束电极对典型的难切削材料——镍基高温合金GH4169进行了高速电弧放电加工。试验结果表明,在放电峰值电流为500 A时,最大材料去除率可达14 000 mm3/min,而最小电极相对损耗比不超过1%,且加工后工件的表面硬度低于基体硬度,再铸层和热影响层厚度均小于100μm,有利于切削等后续半精加工工艺的开展。由此可见,高速电弧放电加工的工艺特性使其非常适合于难切削材料的大余量去除加工。使用多孔成形电极分别对不同形状的型腔样件进行了层铣和沉入式高速电弧放电加工,证明了其高效加工三维特征零部件的能力。
[Abstract]:High Speed Arc discharge Machining (Blasting erosion Arc machining,BEAM) based on hydrodynamic arc breaking is a new special machining technology which uses high speed flow field to control arc discharge and efficiently erode workpiece material. The principle and implementation of this technology are essentially different from the traditional (EDM). A new and efficient material removal and processing method is realized by combining the four key elements of high energy density arc, porous electrode with three dimensional surface, high speed working liquid flow field between poles and multiaxial linkage feed. High speed arc discharge machining of nickel base superalloy GH4169, a typical refractory material, was carried out by graphite cluster electrode. The experimental results show that when the peak discharge current is 500A, the maximum material removal rate can reach 14 000 mm3/min, and the minimum relative loss ratio of the electrode is less than 1, and the surface hardness of the workpiece is lower than that of the matrix. The thickness of the recast layer and the heat affected layer are less than 100 渭 m, which is beneficial to the development of the subsequent semi-finishing process such as cutting. It can be seen that high speed arc discharge machining is suitable for large margin removal of hard cutting materials. Layer milling and sinking high speed arc discharge machining of cavity samples with different shapes have been carried out by using porous forming electrodes. The ability of high efficiency machining of 3D characteristic parts has been proved.
【作者单位】：上海交通大学机械系统与振动国家重点实验室;上海交通大学机械与动力工程学院;
【基金】：国家自然科学基金资助项目(51235007,51421092)
【分类号】：TG661

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