(1.哈尔滨工业大学材料科学与工程学院, 哈尔滨 150001;
2.北京航空材料研究所, 北京 100095)
摘 要: 采用新型的喷射沉积工艺制备了Al-2.15Li-1.28 Mg-1.26Cu-0.10Zr合金,对其不同时效状态的拉伸性能及断裂行为进行了研究。实验结果表明,喷射沉积Al-Li合金经190 ℃、20 h 时效后达到峰时效状 态,此时材料的综合性能最优(σb=528 MPa,σ0.2=420 MPa,延伸率为12%)。固溶淬火态实验合金拉伸断口为完全穿晶韧窝型。时效态合金的断裂方式为穿晶和沿晶混合型。随时效时间的延长,沿晶断裂的比例增加。实验合金沿晶断裂的原因是位错的共面滑移、晶界无析出区和晶界平衡相的析出。
关键字: 喷射沉积 快速凝固 Al-Li合金 显微组织 拉伸性能
(1.College of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 ;
2.Beijing Institute of Aeronautical Materials, Beijing 100095)
Abstract:Al-2.15Li-1.28Mg-1.26Cu-0.10Zr alloy was prepared by spray deposition processing, and its tensile properties and fracture behaviour in various aging conditions were investigated. The spray deposited alloy reaches peak age condition after being aged at 190 ℃ for 20 h and obtains the best properties(σb=528 MPa, σ0.2=420 MPa , δ=12%). Fracture surface of the as-quenched alloy is totally dimple-transgranular type, while the failure mode of the aged alloy is a mixed type with intergranular and transgranular fracture. The volume of intergranular fracture increases with the aging time. The intergranular fracture is caused by planar slip of dislocations, the formation of PFZs and equilibrium phases along grain boundary.
Key words: spray deposition rapid solidification Al-Li alloy microstructure tensile property