Ti48Al2Cr2Nb合金高电位腐蚀的电流时间序列相空间重构分析

Phase Space Reconstruction Analysis of Current Time Series for Corrosion of Ti48Al2Cr2Nb Alloy at High Potential

采用相空间重构法,研究Ti48Al2Cr2Nb合金在高电位电化学腐蚀过程中电流密度时间序列的动力学演化特征。结果表明:电化学系统均存在相似结构的吸引子,其轨迹线均分布在45°对角线上,随着时间以一定规律反复折叠和拉伸,且随着电位的提升越来越复杂、光滑,填充区域变大。结合腐蚀形貌可知,吸引子的具体形态与合金在相应电位下的腐蚀行为密切相关:低电位下电流密度较低,合金的腐蚀以点蚀和不均匀的片层溶解为主,吸引子轨迹线不光滑、占有区域小;随着电位增加、电流密度增大,合金的腐蚀行为逐渐以均匀溶解为主,吸引子轨迹线占有区域大,轨迹线较光滑。

The dynamic evolution characteristics of current density time series of Ti48Al2Cr2Nb alloy at high potential electrochemical corrosion were studied by phase space reconstruction method.The result showed that there are a similar structure of attractors in the electrochemical system,and their trajectory lines are distributed on the diagonal of 45° which are repeatedly folded and stretched with a certain law with time. As the increase of potential,the trajectory becomes smoother and more complex,and the filling area becomes larger. Cooperated with the corrosion morphology,the specific morphology of the attractor is closely related to the corrosion behavior of the alloy at the corresponding potential.When the current density is low at low potential,the corrosion behavior is dominated by pitting corrosion and nonuniform corrosion,and the trajectory of the attractor is not smooth and occupies a small region. The current density rises as the potential increases,the corrosion behavior of the alloy is gradually dominated by uniform dissolution,and the trajectory of the attractor becomes smoother and takes up a large region.