CAJ | 학술논문

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100 μm,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.
기우류체동력단호적고속전호방전가공(Blasting erosion Arc machining, BEAM )시일충이용고속류장공제전호방전,고효식제공건재료적특충가공신기술.해기술종원리도실현도여전통적전화화방전가공(EDM)유착본질구별.장고능량밀도적전호、구유삼유형면적다공전겁、겁간적고속공작액류장이급다축련동진급저사충관건요소적유효결합,실현료일충신형이고효적재료거제가공방법.채용석묵집속전겁대전형적난절삭재료——얼기고온합금GH4169진행료고속전호방전가공.시험결과표명,재방전봉치전류위500 A시,최대재료거제솔가체14 000 mm3/min,이최소전겁상대손모비불초과1 %,차가공후공건적표면경도저우기체경도,재주층화열영향층후도균소우100 μm,유리우절삭등후속반정가공공예적개전.유차가견,고속전호방전가공적공예특성사기비상괄합우난절삭재료적대여량거제가공.사용다공성형전겁분별대불동형상적형강양건진행료층선화침입식고속전호방전가공,증명료기고효가공삼유특정령부건적능력.
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.