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为评价高速列车用PU(聚氨酯)胶粘剂在我国不同气候环境中的适应性,选择武汉、漠河、尉犁和万宁地区作为样品自然老化的试验区,对曝晒90、183、365 d后的PU胶粘剂本体试样及铝合金胶接件进行力学性能、粘接性能和结构的测定。研究结果表明:试样表面裂纹扩展受湿热老化、光老化过程的协同作用影响较大;老化初期,光降解作用萌生细裂纹龟裂,而湿热水解作用产生凹坑,并且对裂纹扩展影响较大;水渗透至基底金属处产生腐蚀,使PU胶粘剂/铝合金胶接件的界面粘接力明显降低。
In order to evaluate the adaptability of PU (polyurethane) adhesive for high speed trains in different climatic environments in China, Wuhan, Mohe, Weili and Wanning were selected as the natural aging test samples. The PU adhesive Body samples and aluminum alloy adhesive mechanical properties, adhesion properties and structure determination. The results show that the crack growth on the surface of the sample is greatly affected by the synergistic effect of heat and moisture aging. At the initial stage of aging, photodegradation can initiate the cracking of the fine cracks, while the hydrothermal hydrolysis produces pits, ; Water infiltrated to the base metal corrosion, so that PU adhesive / aluminum alloy adhesive interface significantly reduced the adhesion.