周浸腐蚀对三明治结构自冲铆接头力学性能的影响

Effect of Periodic Immersion Corrosion on Mechanical Properties of Sandwich Structure Self-piercing Riveted Joint

通过盐溶液周期浸润（简称周浸）腐蚀试验，研究了以AA5052铝合金为基板的泡沫铁镍夹层结构的自冲铆接头的耐腐蚀性能。对不同腐蚀时间的接头进行了拉伸一剪切试验，探究了接头的失效形式，揭示了腐蚀对接头抗剪强度的影响规律。结果表明：不同腐蚀时间接头的拉伸失效模式不同，接头的抗剪强度随周浸腐蚀时间的增加呈先增加后递减的变化，失效位移在周浸腐蚀的前30d先减小再增加，而30d以后逐渐减小，这主要是受接头内部界面上腐蚀行为的影响。

The corrosion resistance of self-piercing riveted joints of foam iron-nickel sandwich structure with AA5052 aluminum alloy as substrate was studied by means of periodic soakage corrosion test in salt solution. The tensile-shear tests of the joints with different corrosion time were conducted. The failure modes of the residual joints were explored. The influence of corrosion on shear strength of residual joints was revealed. The results show that： the tensile failure modes of the joint with different corrosion time are different. The shear strength of the joints increases firstly and then decreases with the increase of the corrosion time. The failure displacement decreases firstly and then increases during first 30 d of the periodic immersion corrosion,but gradually decreases after 30 d, which are mainly affected by the corrosion behavior at the internal interface of the joint.