Ti-48Al-2Cr-2Nb合金在流动电解液中的钝化行为及非线性动力学分析

Nonlinear Dynamic Analysis of Ti-48Al-2Cr-2Nb Alloy Passivated Film in Flow Field

探究Ti-48Al-2Cr-2Nb合金钝化膜的稳定性和形成过程以提高电解加工中的抗杂散腐蚀。通过循环伏安曲线确定了Ti-48Al-2Cr-2Nb合金的钝化电位,通过相空间重构、递归图及其定量分析确定系统的波动程度和稳定性,并运用形核曲线和功率谱密度分析钝化膜的形成过程。结果表明,Ti-48Al-2Cr-2Nb合金在20% NaNO_(3)溶液中的钝化区间为0~1.8 V,进而依次选取0.8、1.0、1.2、1.4、1.6 V这5个电位的钝化区间,分析动态流场下形核曲线,发现钝化膜的成膜过程主要是扩散的方式控制瞬间形核以及三维生长方式进行,然后通过功率谱密度发现钝化膜的生长过程受到粒子的分形布朗扩散影响。通过分析钝化过程的非线性动力学行为,发现相空间重构的吸引子整体波动程度较小的电位有1.2V和1.4V,且通过递归定量分析,发现1.2V电位下系统具有很强的周期性。

For improving the resistance to stray corrosion in electrochemical machining,the stability and forming process of Ti-48Al-2Cr-2Nb alloy passivation film is studied.The passivation potential of Ti-48Al-2Cr-2Nb alloy is determined by Cyclic Voltammetry,the fluctuation degree and stability of the system are determined by phase space reconstruction,recurrence plot and recurrence quantitative analysis,and the formation process of passivated film is analyzed by nucleation curve and power spectral density.The results show that the passivation interval of Ti-48Al-2Cr-2Nb alloy in 20%NaNO_(3) solution ranges from 0 V to 1.8 V and then the passivation intervals of 0.8,1.0,1.2,1.4 and 1.6 V are selected successively.By analyzing the nucleation curve under dynamic flow field,it is found that the formation process of passivated film is mainly controlled by diffusion mode and three-dimensional growth mode,and then it is found by power spectral density that the growth process of passivated film is affected by particle fractal Brownian diffusion.By analyzing the nonlinear dynamic behavior of the passivation process,it is found that the potentials of the phase space reconstruction attractor with small overall fluctuation degree are 1.2 V and 1.4 V,and by recursive quantitative analysis,it is found that the system has a strong periodicity at 1.2 V potential.