In situ self-generation and joint strengthening mechanisms of low melting point layered Mg-Zn fillerOA
Brazing of magnesium(Mg)alloys is critical for lightweight structural application,but the inherent brittleness of intermetallic compounds(IMCs)formed in conventional Mg alloy fillers severely limits joint reliability and precision.In this work,a novel in situ self-generating Mg-Zn filler was developed through rolling compounding and diffusion reactions to enable low-temperature precision brazing.The filler significantly enhances joint performance,achieving a maximum shear strength of 54.6 MPa.This exceptional strength originates from the formation of anα-Mg/Mg_(7)Zn_(3)(MgZn_(2))soft-hard biphasic heterostructure during brazing solidification.The ductileα-Mg phase effectively blunts crack tips,suppresses crack propagation,and relieves stress concentration in the hard-brittle Mg_(7)Zn_(3)(MgZn_(2))phases,improving overall toughness and reliability.Meanwhile,rapid Zn diffusion during brazing induces atomic size mismatch within theα-Mg matrix,generating lattice distortion and dislocation proliferation.These structural defects lower the nucleation barrier of IMCs and promote the formation and localized melting of Mg_(7)Zn_(3),which triggers gradient melting of the filler and enables effective low-temperature joining.This work provides a new filler design strategy and theoretical insights for advancing precision brazing of lightweight Mg alloys.
Rui-nan Chen;Kun-kun Deng;Yu-man Zhu;Cui-ju Wang;Kai-bo Nie;Quan-xin Shi;Yi-jia Li
Shanxi Key Laboratory of Advanced Magnesium Matrix Materials,College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan,ChinaShanxi Key Laboratory of Advanced Magnesium Matrix Materials,College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan,ChinaDepartment of Mechanical and Aerospace Engineering,Monash University,Clayton,VIC 3800,AustraliaShanxi Key Laboratory of Advanced Magnesium Matrix Materials,College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan,ChinaShanxi Key Laboratory of Advanced Magnesium Matrix Materials,College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan,ChinaShanxi Key Laboratory of Advanced Magnesium Matrix Materials,College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan,ChinaShanxi Key Laboratory of Advanced Magnesium Matrix Materials,College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan,China
矿业与冶金
Magnesium alloyBrazingIntermetallic compoundDiffusion reactionFracture behavior.
《Journal of Magnesium and Alloys》 2026 (6)
P.431-445,15
financially supported by the National Natural Science Foundation of China(Nos.U2441260,52271109 and 52401162)Natural Science Foundation of Shanxi(Nos.202403021211064 and 202403011212003)the Major Special Plan for Science and Technology in Shanxi Province(No.202201050201012).
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