Acoustic emission investigations into electrical discharge machining

电火花加工（EDM）是一种精密的材料去除工艺，它利用工具和工件之间快速（~20-100 kHz）火花放电产生的热量，这些火花被一个充满电介质流体的小间隙隔开。一次放电需要4个不同的阶段：(1)在工具和工件之间施加电压，(2)电介质击穿导致等离子体形成，(3)工具和工件之间的放电导致电流流动，导致工具和工件的熔化和汽化，以及(4)等离子体通道的内爆，将物质从熔池中喷射出来，随后是熔融颗粒的冲洗和凝固。上述间隙现象所涉及的物理学相当复杂，目前还没有得到很好的理解。在此背景下，提出的研究计划旨在开发一种简单而新颖的方法来研究电火花加工中的声发射（AE）。

Electrical discharge machining (EDM) is a precision material removal process that utilizes the heat generated from rapid (~20-100 kHz) spark discharges between the tool and the workpiece that are separated by a small gap filled with a dielectric fluid. A single discharge entails 4 distinct stages: (1) application of a voltage between the tool and the workpiece, (2) dielectric breakdown leading to plasma formation, (3) discharge between the tool and the workpiece leading to the flow of a current resulting in melting and vaporization of both the tool and the workpiece, and (4) implosion of the plasma channel that ejects material off the molten pool, followed by flushing and solidification of the molten particles. The physics involved in the gap phenomena above are rather complex and currently not well understood. In this context, the proposed research program seeks to develop a simple but novel approach to investigate acoustic emission (AE) in EDM.