单脉冲放电过程中熔池及材料蚀除的高速摄像观测研究

High-speed Observation of Molten Pool and Material Removal During Single Discharge Process

尽管电火花加工技术获得了很大发展,但电火花加工的极间微观现象仍存在很多未知。采用一种新的观测方法,利用高速摄像机实现了对单脉冲放电过程中的熔池及材料蚀除过程的观测。结果表明:放电过程中熔池内的熔融金属处于漩涡运动状态,在放电开始后最初的短暂时间内材料蚀除剧烈,材料骤然气化的同时伴随着熔融材料的抛出;在之后的放电持续过程中发现了熔融液滴抛出现象和熔融金属爆破现象;放电结束后熔池中的绝大部分熔融金属没有被蚀除,而是重新凝固形成熔融再凝固层。

Electrical discharge machining(EDM)technology has developed great developed rapidly,however,EDM gap phenomena are very complicated and hence not yet fully understood.In this study,a new observation method was used to observe the molten pool and material removal process during single pulse discharges using a high-speed camera.The observation results show that during the discharge duration the molten metal in the melting pool was moving in a swirl.In the initial short period after the discharge began,the electrode material was suddenly vaporized accompanied by the ejection of the molten material,and then the phenomena of molten metal droplet ejection and molten metal blasting can be found during the subsequent discharge duration.After discharge ends,most of the molten metal has not been removed,but was re-solidified.