摘要
镁锂合金是一种新兴的超轻材料,具有比强度和比刚度高、弹性模量高、塑性和冲击韧性好等优点,是航天航空、兵器工业、核工业、汽车和医疗器械等领域理想的结构材料之一。镁锂合金的迅速发展和应用对其连接提出了新的要求,需要研发合适的焊接方法来实现合金连接,并逐步取代铆接等机械连接方式。目前镁锂合金的焊接方法主要集中于非熔化极惰性气体保护焊(TIG焊)、激光焊、电子束焊和搅拌摩擦焊。熔焊方法的核心问题在于热输入的控制,把控不当会导致焊接缺陷、晶粒粗化、合金元素烧损和未焊透等问题,虽然搅拌摩擦焊可以在很大程度上避免这些缺陷,但其本身也存在焊后延伸率大幅下降的问题。当前学者的研究主要集中于焊接工艺、接头组织和力学性能等方面,经过相关的探索研究成功实现了镁锂合金的焊接。目前,镁锂合金的各种焊接方法在工艺研究上都取得了较好的效果,能够在较宽的工艺窗口下得到成形良好、无缺陷的焊接接头;在合适的焊接工艺下,焊缝区晶粒显著细化,甚至出现纳米级晶粒,部分研究中焊接接头各区域组织均匀,成功得到极窄的热影响区;大部分学者的研究都表明焊接接头的抗拉强度和焊缝的硬度得到提高,采用人工时效处理以恢复接头的延伸率具有良好的前景。为进一步推广镁锂合金焊接技术的实际应用,本文对TIG焊、激光焊、电子束焊和搅拌摩擦焊方法得到的焊缝成形、接头微观组织和力学性能进行了综述,分析和探讨了不同焊接方法在镁锂合金焊接中存在的核心问题以及可能的解决措施,并对镁锂合金焊接技术未来的探索方向进行了思考和展望。
Magnesium-lithium alloy( Mg-Li alloy) is a type of rising ultra-light material with a series of advantages,such as high specific strength and specific stiffness,high Young’s modulus,excellent plasticity and impact toughness,which is one of the ideal structural materials in aerospace and aviation,weapon,nuclear,vehicle,medical equipment and other fields. With the rapid development and application of Mg-Li alloy,new requirements for the joining of Mg-Li alloy arise. Appropriate welding methods need to be developed to achieve the join and replace the mechanical joint such as riveting gradually. Currently,the welding methods of Mg-Li alloy mainly focus on tungsten inert gas arc welding( TIG welding),laser welding,electron beam welding and friction stir welding.The core problem of fusion welding is the control of heat input. Improper control will lead to welding defects,such as grain coarsening,element loss and incomplete penetration,etc. Although friction stir welding can avoid these defects to a large extent,deteriation in joint elongation is difficult to avoid. At present,the research mainly focus on weld process,microstructure and mechanical properties of joints,and the welding of MgLi alloy is successfully realized through the exploratory research.Currently,many remarkable achievements about study of Mg-Li alloy welding process have been achieved,and well-formed and defect-free joints can be obtained under a wide process window. Under the appropriate welding process,the grain in the weld zone was significantly refined,and nanoscale grains even appeared. In some studies,the microstructure distribution of the welded joint was uniform,and extremely narrow heat affected zone was successfully obtained. Most studies have shown that the tensile strength of joints and the hardness of welds are improved,and artificial aging treatment to restore the elongation of joints has a good prospect.In order to further popularize the practical application of Mg-Li alloy welding technology,the joint formation,microstructure and mechanical properties obtained by the above welding methods were reviewed in this paper. The core problems and probable solutions of different welding methods in Mg-Li alloy welding were analyzed and discussed. The exploration direction of Mg-Li alloy welding technology in the future was considered and prospected.
作者
刘沁钰
周利
戎校宇
杨海峰
赵洪运
LIU Qinyu;ZHOU Li;RONG Xiaoyu;YANG Haifeng;ZHAO Hongyun(State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China;Shandong Provincial Key Laboratory of Special Welding Technology,Harbin Institute of Technology at Weihai,Weihai 264209,Shandong,China;JianRui New Material Technology Co.,Ltd at Ningbo,Ningbo 315400,Zhejiang,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2022年第10期146-155,共10页
Materials Reports
基金
国家自然科学基金面上项目(51974100)
山东省重点研发计划(2018GGX103053)。
关键词
镁锂合金
焊接技术
微观组织
力学性能
magnesium-lithium alloy
welding technology
microstructure
mechanical property
