Experimental study on electrochemical machining of titanium alloy TC4 twisted blades

Titanium alloy TC4 is widely used as the material of aero-engine blade, which is a typical difficult-to-process material. Electrochemical machining (ECM) is the preferred processing technology for titanium alloy TC4 because it does not depend on the strength and hardness of the material itself, high processing efficiency, and good surface quality. In this paper, the flow field characteristics and experiments of ECM of titanium alloy TC4 twisted blades are studied. According to the characteristics of the blade itself, the lateral flow tangential inlet flow field and the corresponding complex fixture and tool electrode are designed. The theoretical and geometric models of the flow field simulation are established, and the finite element simulation analysis of the flow field is carried out. The results show that the electrolyte flow rate in the new flow field is high and evenly distributed, and there is no shortage of liquid and vortex defects, which can meet the needs of ECM. The experiments of ECM parameters optimization are carried out, and it is found that pulse frequency and duty cycle have a key effect on the surface quality of titanium alloy TC4 blade. The experimental results show that the machining process is very stable under the new flow field mode and optimized machining parameters. The surface of the titanium alloy TC4 blade is bright and without defects. The surface roughness of the concave and the convex are Ra 0.44 μm and Ra 0.47 μm, respectively. The profile accuracy of concave and convex were -0.008 ~ +0.057 mm and -0.002 ~ +0.059 mm, respectively.