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所属单位：机电学院

发表刊物：JOURNAL OF MATERIALS PROCESSING TECHNOLOGY

关键字：Electrochemical machining Passive film Breakdown time Cylindrical electrode Rotational speed

摘要：In electrochemical machining (ECM), a passive film is generally present on the anode surface at low current density but is broken down at high current density in a passivating electrolyte. This film can impede unwanted metal dissolution in a low-current-density region and thereby improve the accuracy of ECM. However, it may sometimes affect metal dissolution at high current density. In this paper, the breakdown time of the passive film is determined for different current densities by varying the applied anodic potential pulses. It is found that the breakdown time has a significant magnitude of a few seconds, which can be long enough to affect metal dissolution in ECM. To illustrate the effect of the breakdown time of a passive film, ECM tests with cylindrical electrodes at different rotational speeds are conducted. The results indicate a correlation between the breakdown time and the rotational speed. At a high rotational speed, the surface of the anode workpiece is always in a passive state due to the existence of the breakdown time of a passive film, and hardly any material is removed. When a slower rotational speed is used, the steel passivity can be overcame, and a high material removal rate is obtained. A numerical simulation of the current density distribution on the cylindrical anode surface is performed, and the relationship between total metal dissolution time and breakdown time is found. It is seen that the breakdown time of the passive film can have a strong effect on the metal removal rate in ECM. (C) 2016 Elsevier B.V. All rights reserved.

ISSN号：0924-0136

是否译文：否

发表时间：2017-01-01

合写作者：朱增伟,He, Bin,Ge, Yongcheng,朱荻

通讯作者：王登勇