Nonlinear Dynamic Dissolution Behavior of Ti-48al-2cr-2nb Alloy

Chronoamperometry (CA), phase space reconstruction, correlation dimension, multifractal detrended fluctuation analysis (MFDFA) combining linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and surface morphology observation were used to systematically analyze the nonlinear dynamic dissolution behavior of Ti-48Al-2Cr-2Nb alloy. The relationships of applied potential E with nonlinear dynamic characteristic (saturation correlation dimension D2’, Hurst exponent H, complexity coefficient Nc) and electrochemical corrosion parameters (capacitance ratio (Ca/Cb)) were analyzed, respectively. Capacitance ratio Ca/Cb reveals the degree of coarsening of the corroded samples after electrochemical corrosion at different potentials, which is closely related to the dissolution behavior of Ti-48Al-2Cr-2Nb alloy. The result of phase space reconstruction proves that current density at each potential has a strange attractor with a rodlike structure and implies the fluctuation behavior of current density and dissolution behavior of Ti-48Al-2Cr-2Nb alloy. Saturated correlation dimension D2’ can determine the minimum embedding dimension m’, which implies the number of major variables in the electrochemical system. Complexity coefficient Nc and Hurst exponent H prove that evolution characteristics of current density at higher potential become more and more regular