The effect of thermal fatigue on the mechanical properties of the novel fiber metal laminates based on aluminum-lithium alloy

The effect of thermal fatigue on the mechanical properties of the novel fiber metal laminates (FMLs) based on aluminum-lithium alloy was investigated. The results indicated that no obvious delamination or defects were observed in the novel FMLs exposed to 1000 cycles. The samples treated with different cycles still exhibited stable and excellent interlaminar properties comparing with the as-manufactured ones. Furthermore, the tensile and flexural strength of the FMLs even increased with the thermal fatigue cycles owing to the positive age hardening behavior of aluminum-lithium layer. The homogeneous and fine precipitation of T1 phases dominated the strengthening effect of aluminum-lithium alloy. Besides, the novel FMLs after thermal fatigue treatments still possessed the similar resistance to fatigue crack growth (FCG) when compared with the as-manufactured ones. The slight changes in the properties of aluminum-lithium layers had no detrimental effect on the FCG.