High‐Dissolution Mechanism of Ti–48Al–2Cr–2Nb Alloy in Electrochemical Machining from a Nonlinear Dynamic Perspective

Abstract

The high‐rate dissolution process of Ti‐48Al‐2Cr‐2Nb alloy in electrochemical machining exhibits strong nonlinear dynamic characteristics, but the quantitative relationship between these nonlinear characteristics and surface topography, as well as the electro‐dissolution mechanism, is unknown. Therefore, the fractal and recursive features of dissolution behavior was investigated, and the dissolved surface topography was quantitatively characterized. Additionally, an electro‐dissolution mechanism model in electrochemical machining process was presented. Applying a moderate extraction potential of 8 V instead of 11 V can enhance the stability of the electrochemical system, resulting in a smoother and uniform surface. At 11 V, the saturation correlation dimension, surface roughness, and integral area of lacunarity initially decrease before increasing with higher electrolytic pressure, while laminarity (𝐿𝐴𝑀) and determinism (𝐷𝐸𝑇) show an initial increase followed by a decrease. These five characteristic parameters reach their optimal values at an electrolyte pressure of 0.4 MPa, indicating that achieving a stable and deterministic electrochemical system is crucial for obtaining a uniform smooth surface. These nonlinear dynamic characteristic parameters can be considered as in‐situ monitoring parameters for surface quality in ECM. The anodic dissolution process comprises three stages: initial passive film dissolution and breakdown, rapid dissolving with surface coarsening, and stable dissolving with polishing.This article is protected by copyright. All rights reserved.