Abrasive-assisted Counter-rotating Electrochemical Machining of Titanium Alloy Thin-Walled Revolving Parts: Simulation Analysis and Experimental Investigation

Aiming at the problems and challenges of uneven dissolution and poor surface quality in counter-rotating electrochemical machining (CRECM) of easily passivated materials such as titanium alloy, a novel abrasive-assisted counter-rotating electrochemical machining (AA-CRECM) method is proposed in this paper. Based on the proposed method, a multi-physical model is established using computational fluid dynamics (CFD) to simulate the flow field, workpiece curvature and abrasive erosion. Then, the experimental investigation, surface characterization and electrochemical test are conducted. Simulation and experimental results show that the inlet water flow from the cathode impacts the wall and rapidly diffuses to both sides, resulting in a uniform flow field in the processing zone. The abrasive erosion distribution is more concentrated and stable under 0.03 MPa conditions. As the workpiece curvature decreases, the particle residence time and particle trajectory are more concentrated in the central region. In the experiment, the AA-CRECM process notably improves the surface quality, volume material removal rate and surface hardness. Compared with the CRECM without abrasive assistance, the surface roughness R a is significantly reduced from 53.835 μm to 1.728 μm. The polarization curves and EIS results further confirm that abrasive assistance weakens the passivation barrier and enhances the electrochemical activity of the machined surface. Simultaneously, the volume material removal rate under AA-CRECM reached 237.753 mm 3 /min, approximately 1.84 times that of the CRECM without abrasive assistance. Furthermore, the surface hardness is increased to 1.08 times that of the CRECM without abrasive assistance. On this basis, the efficient and stable machining of titanium alloy thin-walled revolving parts with a wall thickness of 1.8 mm is successfully realized. This method enhances the ability of CRECM for high-efficiency, high-precision, and high-quality machining of thin-walled titanium alloys and provides valuable insights for wider ECM applications involving easily passivated materials.