时效制度对SLM成形2196铝锂合金组织与力学性能的影响  

Effect of the Aging Process on the Microstructure and Mechanical Properties of 2196 Al-Li Alloy Fabricated via Selective Laser Melting

作　　者：李雪萍 王前 沈宇凡[1,2] 王亚光 咸舒凡 王猛 LI Xueping;WANG Qian;SHEN Yufan;WANG Yaguang;XIAN Shufan;WANG Meng(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;MIIT Key Laboratory of High Performance Additive Manufacturing and Innovative Design of Metal Structure,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西北工业大学金属高性能增材制造与创新设计工业和信息化部重点实验室,陕西西安710072

出　　处：《铸造技术》2024年第12期1138-1144,共7页Foundry Technology

基　　金：国家重点研发计划(2022YFB4602301);国家自然科学基金(52275381);陕西省“双链融合”增材制造重点专项(2021LLRH-08)。

摘　　要：铝锂合金在航空航天构件制备中应用潜力巨大。激光选区熔化成形(SLM)技术在复杂轻量化结构整体成形方面具备独特优势,但SLM直接成形的铝锂合金力学性能较低,需要通过热处理优化其力学性能。本文研究了T6时效和双级时效制度对SLM成形2196铝锂合金组织性能的影响。结果表明,170℃/36 h(T6)时效处理后,在纳米T_(1)(Al_(2)CuLi)强化相的作用下,强度大大提高,但断后伸长率明显下降;130℃/6 h+170℃/24 h时效处理后,T_(1)相尺寸更小,数密度更高,强度和断后伸长率均高于T6态;170℃/36 h+115℃/4 h时效处理后,合金中额外形成了大量原子团簇,在保持断后伸长率的同时,强度再次提高。Aluminium-lithium alloys have great application potential in aerospace component preparation.Selective laser melting(SLM)technology has unique advantages in the integral formation of complex and lightweight structures,but the mechanical properties of Al-Li alloys formed by SLM directly are poor,requiring heat treatment to maximize their mechanical properties.This study examined the impact of T6 treatment and double-stage aging on the microstructure and properties of a 2196 Al-Li alloy built via SLM.The results demonstrate that after 170℃/36 h(T6)aging treatment,the strength is greatly improved because of the precipitation of nano-T_(1)(Al_(2)CuLi),but the elongation decreases dramatically.After the 130℃/6 h+170℃/24 h aging treatment,the samples show both greater strength and elongation than those in the T6 state because of the smaller size and higher number density of the T_(1) phase.After the 170℃/36 h+115℃/4 h aging treatment,a large number of additional atomic clusters form in the alloy,and the strength increases again while the elongation is maintained at the same level.

关 键 词：激光选区熔化 2196铝锂合金 T6时效 双级时效 T1(Al2CuLi)相 

分 类 号：TG146.2[一般工业技术—材料科学与工程]