不同时效状态对2A97铝锂合金薄板疲劳损伤行为的影响  

Influence of Aged States on the Fatigue Damage Behaviors of 2A97 Al-Li Alloy Thin Plate

作　　者：虞朝智 李国爱 王亮[1,2] 郝时嘉 郝敏 王向杰 Yu Chaozhi;Li Guoai;Wang Liang;Hao Shijia;Hao Min;Wang Xiangjie(Beijing Institute of Aeronautical Materials,Beijing 100095,China;Beijing Engineering Research Center of Advanced Aluminum Alloys and Applications,Beijing 100095,China;Northeastern University,Key Lab of Electromagnetic Processing of Materials,Ministry of Education,Shenyang 110819,China)

机构地区：[1]北京航空材料研究院,北京100095 [2]北京市先进铝合金材料及应用工程技术研究中心,北京100095 [3]东北大学材料电磁过程研究教育部重点实验室,辽宁沈阳110819

出　　处：《科学技术创新》2022年第18期58-61,共4页Scientific and Technological Innovation

基　　金：国家自然科学基金项目(U1708251,U1608252;51474195;51574075资助)。

摘　　要：对不同时效状态下2A97铝锂合金薄板的拉伸性能、疲劳损伤过程以及微观组织特征进行了研究。结果表明,从T3至T8状态,合金的强度逐渐增加,但疲劳损伤性能急剧降低,疲劳裂纹扩展方式也由T3状态的多晶粒多系滑移-穿晶微裂纹为主逐渐演变为T8状态的晶内位错聚集-沿晶微裂纹为主。微观组织观察结果表明,不同状态中析出相类型及分布具有很大不同,这些差异直接影响了疲劳裂纹萌生、扩展过程中位错的增殖及扩展方式,最终影响了合金的疲劳寿命。Tensile properties,fatigue damage process and corresponding microstructure of 2A97 Al-Li alloy sheets under different aging conditions were investigated.The results show that from the T3 to T8 states,the tensile strength gradually increases,while the fatigue damage performance decreases sharply.The fatigue crack propagation is dominated by the transgranular crack mode caused by multi-slip in the T3 state and gradually evolves into the intergranular microcracks caused by the aggregation of dislocations in the grains of the T8 state.TEM microstructure observation results show that the types and distributions of the precipitates in the alloys in different states are significantly different.It is proposed that these differences directly affect the dislocation multiplication and propagation modes during the initiation and propagation of fatigue cracks,which ultimately affects the fatigue life of alloys.

关 键 词：2A97铝锂合金 轴向疲劳试验 疲劳损伤过程 微观组织特征 

分 类 号：TG146.21[一般工业技术—材料科学与工程]