Electrochemical cutting with inner-jet electrolyte flushing for titanium alloy (Ti-6Al-4V)

Abstract

Titanium alloys are widely used in aerospace, weapon equipment, biomedicine, and other fields because of their excellent material properties. Thus, corresponding cutting technologies that can achieve high efficiency and high quality have become the focus of research. Electrochemical cutting is a machining method that uses linear metals (wires, rods, or tubes) as the tool cathode to dissolve and remove the local material of the anode workpiece in a two-dimensional plane. This results in high-quality ruled surface structures with no burrs, recasting layers, and micro-cracks on the machining surface. However, in the electrochemical machining of titanium alloys, the electrolysis products are mostly insoluble floccules that are easily adsorbed on the machining surface, making it difficult for conventional wire electrochemical machining to complete the cutting process. To solve this problem, the electrochemical cutting of Ti-6Al-4V by inner-jet electrolyte flushing with a tube electrode is investigated. Experiments show that the optimal trade-off between machining efficiency and machining accuracy is achieved when 5% NaNO3 + 5% NaCl electrolyte is used. Furthermore, the method of inner-jet electrolyte flushing assisted by outer-jet electrolyte flushing can be used to wash away the electrolysis products in the slit that has been cut, thus eliminating the local corrosion phenomenon on the upper surface of the slit caused by the accumulation of electrolysis products. Finally, the optimal nozzle diameter, flow rate, and electrolyte temperature were selected, and several typical structures are machined on a 10-mm-thick Ti-6Al-4V alloy block using the 5% NaNO3 + 5% NaCl electrolyte and outer-jet electrolyte flushing-assisted machining.