汽车用镀锌板单搭接胶接接头强度影响因素研究

Study on influencing factors of single lap adhesive joint strength of galvanized sheet for automobile

针对不同种类汽车用镀锌板单搭接胶接接头强度的影响因素进行了研究分析。考察了不同腐蚀介质及汽车涂装工艺对汽车板胶接接头性能的影响,并深入研究了其失效机理。研究结果表明:汽车板材料的屈服强度、材料厚度以及胶层厚度等均会对胶接接头的力学性能产生一定的影响;为保证胶接工艺在汽车车身结构中发挥最佳的力学性能,且与电泳工艺段同步,温度应控制在175~185℃之间,且时间20~30 min为宜;在胶层材质及厚度一致的条件下,汽车板材料的屈服强度越高,其在拉伸过程中发生塑性变形对应的拉伸力越高,胶接接头可承受的拉伸剪切强度也越高;腐蚀介质同样会对汽车胶接接头的拉伸剪切强度造成不同程度的影响,Cl^(-)对胶接接头中胶层成分及力学性能的破坏更为严重;在实际的汽车板胶接工艺中,需将涂装工艺对胶接接头性能的影响加以考虑。

The influencing factors of single lap adhesive joint strength of different kinds of galvanized sheet for automobile were studied and analyzed. The effects of different corrosive media and automobile painting processes on the properties of automobile sheet adhesive joint were investigated,and their failure mechanism was deeply studied. The research results showed that the yield strength,material thickness and adhesive layer thickness of automotive sheet material would all have a certain impact on the mechanical properties of adhesive joint. In order to ensure that the bonding process could give full play to the best mechanical properties in the automobile body structure and synchronize with the electrophoresis process section,the temperature should be controlled between175-185 ℃ and the time should be 20-30 min. Under the condition of the same material and thickness of adhesive layer,the higher the yield strength of automobile sheet material,the higher the tensile force corresponding to the plastic deformation in the tensile process,and the higher the tensile shear strength of adhesive joint. Corrosive medium would also have different effects on the tensile shear strength of automobile adhesive joint,and Cl^(-) would cause more serious damage to the composition and mechanical properties of adhesive layer in adhesive joint. In the actual automobile sheet bonding process,the influence of coating process on the performance of adhesive joint should be considered.