Ultrasound-Assisted Through-Mask Electrochemical Machining of Hole Arrays in ODS Superalloy

Abstract

Micro-hole arrays have found wide applications in aerospace, precision instruments, and biomedicine. Among various methods of their production, including mechanical, laser, and electrical discharge, electrochemical machining (ECM) is considered the most lucrative due to its wide processing range, high surface quality, and excellent productivity. In particular, ultrasound-assisted through-mask ECM exhibits an enhanced machining precision due to ultrasonic cavitation, which promotes the removal of the electrolytic products and bubbles. In this study, the equation of cavitation bubble oscillation was derived and numerically solved to study the influence of six different parameters on the ultrasonic cavitation and electrolysis process, and their optimal values were determined. The feasibility of the proposed ultrasound-assisted through-mask ECM technology with the optimized parameters was experimentally corroborated by the fabrication of a high-quality hole array in an oxide dispersion strengthened (ODS) MA956 superalloy.

Selected Aspects of Electrochemical Micromachining Technology Development

“…Therefore, the range of application of sinking operation in micromachining is limited to manufacturing cavities or holes with simple cross-section (i.e., cylinder, and polygon) and is preferred in mezzo-manufacturing (i.e., where machined area is in range of mm 2 ) (example in Figure 6 ). Through-mask electrochemical micromachining was developed especially, to generate the micro-dimples array with controlled shape and density and this process also includes masking to protect selected areas of workpiece from dissolution [ 12 , 29 ]. Therefore, in micromachining application dominant are the operations where simple electrode-tool (i.e., cylindrical with spherical, or flat or tip, wire) can be applied [ 30 , 31 ].…”

“…(5) development of power suppliers and gap control strategy [10]; and (6) improvement of machining conditions by additional energy sources (i.e., ultrasonic vibrations [11,12]) or (7) integration with other technologies [13].…”

“…It is related to selection of optimal conditions of dissolution under the small interelectrode gap (<100 μm). The scope of the conducted research includes especially: (1) explanation of the phenomena in interelectrode gap during dissolution [ 5 ]; (2) analysis and modification of electric current distribution on the workpiece surface [ 6 , 7 ]; (3) selection of optimal composition of electrolyte [ 8 ]; (4) technology development, i.e., simulation of machining or the tool shape/path design [ 9 ]; (5) development of power suppliers and gap control strategy [ 10 ]; and (6) improvement of machining conditions by additional energy sources (i.e., ultrasonic vibrations [ 11 , 12 ]) or (7) integration with other technologies [ 13 ].…”

Research on Multi-Physics Coupling Simulation for the Pulse Electrochemical Machining of Holes with Tube Electrodes

“…With the rapid development of accuracy and miniaturization in the aerospace, automotive and medical industries, small holes of special shape and groove structures have appeared on many mechanical parts. For example, in order to meet the characteristics of lightweight and high temperature resistance of turbine blades, high temperature resistant cemented carbide [ 1 , 2 , 3 ] is used as the main material of blades and the film cooling holes [ 4 , 5 ] are machined to improve the properties of thermal dissipation. However, traditional machining is difficult to machine microstructures in high temperature resistant cemented carbides.…”

Review Microstructure of Nickel-Based Single-Crystal CMSX-4 Superalloy after Electrochemical Machining

“…Hence, the electrons moved, the ions separated from the workpiece's surface, and hydrogen gas is created around the tool. This machining is an anodic dissolution process that follows the Faraday relationship [1][2][3]. In this process, there is no contact between the cathode and the anode, so no stress occurs on the surface of the part, and the problems caused by the heat-affected area, which is a disadvantage of the workpiece in similar methods such as electrical discharge machining, does not exist in this method.…”