TC21钛合金表面涂层体系在多因素综合加速试验条件下的老化规律研究

Evolution Laws of Coated TC21 Titanium Alloy during the Indoor Multi-factor Comprehensive Accelerated Aging Test

目的研究TC21钛合金表面防护体系(酸洗+环氧底漆+聚氨酯面漆)在多因素协同加速试验条件下的表面性能变化规律。方法利用一台海洋大气综合模拟试验装置,在户内模拟热带岛礁海洋大气环境,对经历各个加速试验周期后的试样进行外观拍照、光泽度测试、色差测试、光学显微拍照、以及电化学阻抗测试(EIS),并描述相关变化过程。结果5个周期的加速试验后,试样表面涂层的失光率和色差分别达到45.6%和4.36。涂层在0.01 Hz处的阻抗模值由初始的2.74×1010Ω下降为6.21×107Ω。结论经历5个周期的户内多因素综合加速试验的过程中,TC21钛合金表面涂层体系的防护效果呈持续下降趋势,但5周期后尚未完全失效。

The work aims to study the surface property evolution laws of coated TC21 titanium alloy specimens(acid pickling+epoxy primer+polyurethane top-coat)during the indoor multi-factor comprehensive accelerated aging test.The marine atmosphere environment of tropical island reef was simulated indoors by a marine atmosphere comprehensive simulation test device.The samples after each accelerated test cycle were subject to appearance photo,gloss test,color difference test,optical micrograph and electrochemical impedance test(EIS),and the related change process was described.The glossiness loss rate and the chromatic aberration of the specimens after 5 cycles of accelerated test increased to 45.6%and 4.36,respectively.Additionally,the impedance magnitude of the coating at 0.01 Hz was changed from 2.74×1010Ωto 6.21×107Ω.The anti-corrosion ability of the TC21 titanium coating system is continuously decreasing during 5 cycles of indoor multi-factor comprehensive accelerated aging test,but does not completely fail after total 5 cycles of aging test.accelerated aging test,but does not completely fail after total 5 cycles of aging test.