Electrochemical micromachining of ZrCu-based amorphous alloy in ethylene glycol solution

Their excellent physical, chemical, and mechanical properties give ZrCu-based amorphous alloys a wide range of application prospects as advanced functional and structural materials for military and aerospace uses and in precision devices. Micro-electrochemical technology has been used to process amorphous alloys, and this paper reports the wire electrochemical micro-machining (WECMM) of the Zr67Cu15Ni11Al4Ti3 amorphous alloy. The dissolution characteristics and processing of the alloy in aqueous solutions are analyzed to understand the WECMM of this ZrCu-based amorphous alloy. Unlike with Cu-free Zr-based amorphous alloys, the Cu in the present case is electrolyzed quickly and generates a large amount of product deposition on the surface of the cathode after it is ionized, thereby seriously hindering the processing. Unlike the pure charge-transfer control process in an aqueous solution, the polarization process of the alloy in a glycol solution is controlled by both charge transfer and diffusion. In a glycol solution, the two-phase electric double layer comprises a compact layer and a diffusion layer, ions move relatively slowly between the cathode and anode, and products form relatively slowly. This is effective in (i) strengthening the reverse electric field effect of the bipolar pulse, (ii) hindering the migration of cations to the cathode, and (iii) directly avoiding the formation of products, thereby allowing the formation of high-quality micro-structures of ZrCu-based amorphous alloy with a relatively large thickness of 550 μm.