基于电偶腐蚀仿真的铝/钛合金在不同浓度酸性NaCl溶液中与水介质中的当量折算系数

Equivalent Conversion Coefficient of Aluminum/Titanium Alloy Between Acidic NaCl Solution with Different Concentration and Water Based on Galvanic Corrosion Simulation

以飞机常用材料2A12铝合金和TA15钛合金为研究对象,对两种材料在不同NaCl浓度和不同pH值溶液中的极化曲线和电偶电流进行测量,探究了铝/钛合金在不同NaCl浓度和不同pH值溶液中发生电偶腐蚀时与水介质的当量折算关系。将极化曲线作为边界条件建立电偶腐蚀预测模型,通过该模型计算得到两种金属材料在不同NaCl浓度和不同pH值溶液中的电偶电流并与电化学试验测量结果进行对比分析。结果表明,铝合金的自腐蚀电位主要受溶液中NaCl浓度的影响,溶液pH值的大小对自腐蚀电位的影响不大,但对自腐蚀电流密度影响较为显著。不同NaCl浓度和不同pH值溶液中的模型仿真结果与电化学试验结果相吻合,通过模型计算得到了不同NaCl浓度和不同pH值溶液中2A12-T4铝合金和TA15钛合金发生电偶腐蚀时与水介质中的折算系数。

Polarization curves and current of galvanic corrosion of 2A12 aluminum alloy and TA15 titanium alloy in solution with different NaCl concentrations and pH value were measured by electrochemical test.Conversion coefficient of galvanic corrosion between TA15/2A12 in different concentrations and pH of NaCl solution and aqueous was investigated.A galvanic corrosion simulation model was established by polarization curves of boundary condition in different concentrations NaCl solution with different pH.The galvanic corrosion current of two materials for corrosion simulation model was compared with the electrochemical test.The results showed that the self-corrosion potential of aluminum alloy was mainly affec-ted by the NaCl concentration,but it was less affected by the pH values which had a significant effect on the self-corrosion current.The simulation results agree with the electrochemical test results.Besides,the conversion factors between galvanic corrosion of 2A12-T4 aluminum alloy and TA15 titanium alloy in different NaCl concentrations and pH values solutions and self-corrosion in water medium were obtained by simulation.