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。
A novel high-efficiency arc discharge machining process named blasting erosion arc machining （BEAM） based on hydrodynamic arc-breaking mechanism is proposed and implemented. It substantially differs from electrical discharge machining （EDM）. This technology composes of several key elements, such as high density energy input carried by arcing, multi-hole electrode with three-dimensional contour, high velocity flow field in the discharge gap, and multi-axis feed control. The BEAM is capable of machining 3D complex part with high material removal rate. The machining experiments are conducted with graphite bundled electrode as a tool, and typical difficult-to-cut material GH4169 （similar to Inconel718） as a workpiece. The maximum material removal rate （MRR） reaches 14 000 mm3/min, and the minimum relative tool wear ratio （TWR） is less than 1 % while the peak discharge current is 500 A. Meanwhile, the hardness of machined surface is lower than that of matrix and the thickness of heat affected zone and recast layer are less than 100μm. These imply that the subsequent semi-finishing process such as cutting could be applied easily. Therefore, the machining characteristics of BEAM demonstrate that it is a promising technology to deal with bulk removal roughing of difficult-to-cut materials.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2015年第17期177-183,共7页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(51235007
51421092)
关键词
高速电弧放电加工
流体动力断弧
材料去除率
工具电极相对损耗比
blasting erosion arc machining
hydrodynamic arc breaking mechanism
material removal rate
relative tool wear ratio
作者简介
徐辉，男，1982年出生，博士研究生。主要研究方向为放电加工技术。E—mail：xuhuijg149@sjtu．edu．cn
顾琳（通信作者），男，1974年出生，副教授，博士研究生导师。主要研究方向为特种加工技术及其装备。E-mail：lgu@sjtu．edu．cn
赵万生，男，1957年出生，教授、博士研究生导师。主要研究方向为特种加工技术和微细加工技术。E-mail：zws@sjtu．edu．cn
