不同环境下对2D70铝合金低周疲劳性能的研究

Study on Low Cycle Fatigue Performances of 2D70Aluminum Alloy in Different Environments

对2D70铝合金在试验室空气、湿空气、盐雾(NaCl)及盐雾(NaCl)+二氧化硫(SO2)4种环境下进行低周疲劳试验,对比4种环境下的循环σ-ε曲线及应变-寿命曲线。得出结论,相同应变下,2D70铝合金随腐蚀环境增强,循环应力降低;2D70铝合金在盐雾及盐雾+二氧化硫两种环境下低周疲劳寿命相近,并且随着腐蚀环境的增强,低周疲劳寿命降低;腐蚀环境越强,材料疲劳损伤程度越大。研究结果可为预测飞机机身在不同环境下的低周疲劳寿命提供参考,对飞机腐蚀防护及耐久性设计具有重要意义。

Having done a series of low cycle fatigue tests to 2D70aluminum alloy under different environments which include laboratory air , moist air , NaCl fog and NaCl fog+SO2.Compare the cyclic stress versus strain curves and the strain versus life curves in four circumstances respectively which they can be obtained by above experiments.The conclusion will be made : Under the same strain , the circulation stress of 2D70aluminum alloy reduces along with the corrosion environment strengthens ; Under the same strain , the low cycle fatigue life in NaCl fog is close to the life in NaCl fog+SO 2 of 2D70 aluminum alloy , and the low fatigue life reduces along with the corrosion environment strengthens.The corrosion environment is stronger , and the fatigue damage of materials is bigger.The studies provide the reference to forecast low cycle fatigue lifes of airplane under different environments , and have important meaning on corrosion protection and durable design of airplane.