2195铝锂合金的温热低周疲劳行为和疲劳寿命预测  

Low cycle fatigue behavior and fatigue life prediction of 2195 Al−Li alloy at warm temperatures

作　　者：孟子杰 张存生[1] 吴承格 张豪 陈良[1] 赵国群[1] 闫海 Zi-jie MENG;Cun-sheng ZHANG;Cheng-ge WU;Hao ZHANG;Liang CHEN;Guo-qun ZHAO;Hai YAN(Key Laboratory for Liquid-Solid Structural Evolution&Processing of Materials(Ministry of Education),Shandong University,Jinan 250061,China;School of Construction Machinery,Shandong Jiaotong University,Jinan 250357,China;Jiangsu Haoran Spray Forming Alloy Co.,Ltd.,Zhenjiang 212009,China)

机构地区：[1]山东大学材料液固结构演化与加工教育部重点实验室,济南250061 [2]山东交通学院工程机械学院,济南250357 [3]江苏豪然喷射成形合金有限公司,镇江212009

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第9期2574-2587,共14页中国有色金属学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(No.51975330);the Key Research and Development Program of Shandong Province,China(No.2021ZLGX01);the Project of Colleges and Universities Innovation Team of Jinan City,China(No.2021GXRC030).

摘　　要：为研究2195铝锂合金在温热条件下(100和200℃)的低周疲劳行为,首先进行应变控制的低周疲劳试验。结果表明,合金的起始和中值寿命滞回环均呈现中心对称特征。在100℃、应变幅值为0.6%条件下的循环应力响应曲线表现出完全循环硬化特征,而其他条件下的循环应力响应曲线均呈先循环硬化、然后循环软化的循环特征。随后,采用多种低周疲劳寿命预测模型对2195铝锂合金疲劳寿命进行评价。结果表明,基于总应变能密度的寿命预测模型具有最佳的预测精度。最后,为揭示2195铝锂合金的疲劳断裂机理,对不同试验条件下合金的疲劳断口进行观察。结果表明,在100℃、应变幅值为0.6%的条件下,合金断面上的疲劳条纹十分明显,但随着试验温度和应变幅值的升高,合金断面上的疲劳条纹逐渐弱化。在温度为200℃、应变幅值为1.0%条件下的疲劳断口呈明显沿晶断裂特征。The strain-controlled low cycle fatigue(LCF)tests were firstly carried out to investigate the LCF behavior of the 2195 Al−Li alloy at warm temperatures(100 and 200℃).All initial and mid-life hysteresis loops showed a centrosymmetric characteristic.The cyclic stress response curve at 100℃and strain of 0.6%exhibited complete cyclic hardening,while response curves under other conditions showed cyclic hardening initially followed by cyclic softening.Then,various fatigue life prediction models were employed to evaluate LCF life.The prediction model based on the total strain energy density could present the best prediction accuracy.Finally,the fatigue fracture under different conditions was observed to reveal the fatigue fracture mechanism.The fatigue striations were visible at 100℃and strain of 0.6%,but gradually diminished with increasing temperature and strain.Furthermore,the fatigue fracture zone at 200℃and strain of 1.0%presented an evident intergranular fracture characteristic.

关 键 词：2195铝锂合金 低周疲劳行为 疲劳寿命预测 疲劳断裂行为 

分 类 号：TG146.21[一般工业技术—材料科学与工程]