Investigation on the effect of solid particle erosion on the dissolution behavior of electrochemically machined TA15 titanium alloy

During electrochemical machining (ECM), the passivation film formed on the surface of titanium alloy will lead to uneven dissolution and pitting, and solid particle erosion can effectively re-move the passivation film. In this paper, the electrochemical dissolution behavior of Ti-6.5Al-2Zr-1Mo-1V (TA15) titanium alloy at without particle impact, low- (15°) and high- (90°) angles particle impact was investigated, and the influence of Al2O3 particles on ECM was sys-tematically expounded. It was found that under the condition of no particle erosion, the surface of electrochemically processed titanium alloy had serious pitting corrosion due to the influence of passivation film, and the roughness Sa of local area reached 10.088μm. Under the condition of high-impact angle (90°), due to the existence of strain hardening and particle embedding, only the edge of the surface is dissolved, and the central area was almost insoluble, and the roughness Sa reached 16.086μm. On the contrary, under the condition of low-impact angle (15°), the ma-chining efficiency and surface quality of the material were significantly improved due to the ploughing effect and galvanic corrosion, and the roughness Sa reached 2.823μm. Finally, the electrochemical dissolution model of TA15 titanium alloy under different particle erosion condi-tions was established.