Double-pulsed wire electrochemical micro-machining of type-304 stainless steel

Traditional wire electrochemical micro-machining (WEMM) of type-304 stainless steel using dilute hydrochloric acid (HCl) generates a certain amount of insoluble electrolysis product that adheres onto the wire. As the machining process continues, a blackened layer is generated on the wire that hampers the machining process. Herein, a double-pulsed WEMM (DP-WEMM) method is proposed to eliminate this blackened layer, effectively so as indicated by experimental results. An optimal negative voltage is determined as −0.3 V. The slot profile and machining stability obtained with DP-WEMM are considerably better than those with traditional WEMM. For the same machining parameters and feed rate, traditional WEMM with dilute HCl manages a 1.8-mm-long slot until short circuit occurs. By contrast, DP-WEMM is terminated manually after a 5.0-mm-long slot is obtained, there having been no short circuit.