涂层加速老化与自然曝晒试验的相关性分析

Correlation between accelerated aging of coating and natural exposure test

为了研究加速老化试验与自然曝晒试验的相关性,进行了飞机典型7B04 T74铝合金-30CrMnSiA钢-7B04 T74铝合金双排8个钢螺钉连接件在防护涂层加速谱下6个周期的加速老化试验和海南万宁2年的自然曝晒试验。观测并记录了不同加速周期和曝晒年限的防护涂层失光、变色、粉化、起泡、开裂、剥落和基体腐蚀现象,对加速老化和自然曝晒的防护涂层表观老化特征、基体腐蚀产物进行了对比分析,表明加速老化试验可以再现外场老化特征。考虑到防护涂层老化特征的多属性和动态性,对2种环境下的老化损伤进行了综合量化评估,用指数函数描述老化特征量随时间的变化规律。通过老化动力学规律的对比,给出了当量加速关系的表示形式,并得到了加速谱和海南万宁自然曝晒试验的当量加速关系为0.4年/周期。

In order to study the correlation between accelerated aging test and natural exposure test, a comparative test between the exposure test and accelerated test on typical 7 B04 T74 aluminum alloy-30 CrMnSiA steel-7 B04 T74 aluminum alloy connectors with double row 8 steel screws was carried out. The specimens were accelerated in the protective coating accelerated aging environment for 6 cycles and the natural exposure test of Wanning, Hainan for 2 years, respectively. The aging features including loss of gloss, fading, chalking, bubbling, cracking, flaking and metal substrate corrosion of protective coating were observed and measured, the aging characteristics and matrix corrosion products of accelerated aging and natural exposure protective coatings were compared and analyzed, the comparison on the tested aging characteristics of protective coatings indicates that the accelerated aging test can make the characteristics of the field aging reappear. Considering the multi-attribute and dynamic characteristics of aging characteristics of protective coatings, the aging damage in two environments is comprehensively evaluated quantitatively, and the variation law of aging characteristics with time is described by exponential function. By comparing the aging kinetics, the equation of the equivalent acceleration factor was given. The equivalent acceleration relation between two environments was obtained as 0.4 year/cycle.