Al-Si-Cu-Ni钎料成分和钎焊温度对高硅铝合金/可伐合金钎焊接头性能的影响  

Effect of Al-Si-Cu-Ni Brazing Alloy Composition and Brazing Temperature on Properties of High Silica Aluminum Alloy/Kovar Alloy Brazed Joints

作　　者：邱玉洁 牛济泰[1,2] 杨环宇 木二珍 QIU Yujie;NIU Jitai;YANG Huanyu;MU Erzhen(School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,China;Henan Jingtai Aerospace High-Tech Materials Technology Co.,Ltd,Jiaozuo 454000,China;School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]河南理工大学材料科学与工程学院,焦作454000 [2]河南晶泰航空航天高新材料科技有限公司,焦作454000 [3]大连理工大学材料科学与工程学院,大连116024

出　　处：《机械工程材料》2024年第11期103-110,共8页Materials For Mechanical Engineering

基　　金：河南省高等学校重点科研项目计划(22B470005)。

摘　　要：采用甩带工艺制备Al-7.5Si-23Cu-xNi(x取0,0.5,1.0,1.5,2.0,2.5,质量分数/%)箔状钎料,研究了镍含量对钎料组织和性能的影响;利用性能最好的钎料对CE11高硅铝合金和4J29可伐合金进行真空钎焊,分析了钎焊温度(560~600℃)对接头组织、抗剪强度及气密性的影响。结果表明:随着镍含量的增加,钎料的液/固相线变化较小,熔化温度区间较稳定,铸态钎料局部共晶组织增多,柱状晶变粗大,断裂应变和接头的抗剪强度均先升高后降低;当镍质量分数为2.0%时,钎料的熔化温度区间最小,熔点最低,组织均匀,共晶相较多且弥散分布,钎料的韧性和焊接性能最好。当钎焊温度低于570℃时,Al-7.5Si-23Cu-2.0Ni钎料熔化不完全,与母材结合较差;当钎焊温度高于570℃时,钎料与母材间的元素互扩散剧烈,造成硅相聚集,焊缝中出现裂纹。随着钎焊温度的升高,接头的抗剪强度先升后降,焊后泄漏率先降后升。最佳钎焊温度为570℃,此时焊缝与两侧母材结合紧密,元素扩散均匀,接头的抗剪强度最大,气密性最好。Al-7.5Si-23Cu-xNi(x=0,0.5,1.0,1.5,2.0,2.5,mass fraction/%)foil brazing alloys were prepared by melt spinning technology.The effect of Ni content on the microstructure and properties the brazing alloy was analyzed.Vacuum brazing was conducted on CE11 high silicon aluminum alloy and 4J29 Kovar alloy by using the brazing alloy with the best properties,and the effect of brazing temperature(560‒600℃)on the microstructure,shear strength and air tightness of the joint was discussed.The results show that with the increase of Ni content,the change of liquid/solid phase lines of the brazing alloy was small,the fusion temperature zone was stable,the local eutectic structure of the as-cast brazing alloy increased,and the columnar crystals became coarse.With the increase of Ni content,the fracture strain of the as-cast brazing alloy and the shear strength of the joint first increased and then decreased.When the Ni mass fraction was 2.0%,the brazing alloy had the smallest fusion temperature zone,the lowest melting point,uniform microstructures,more diffusely distributed eutectic phases,and the best toughness and welding performance.When the brazing temperature was lower than 570℃,the Al-7.5Si-23Cu-2.0Ni brazing alloy could not melt completely and the combination with base metal was poor.When the brazing temperature was higher than 570℃,the element diffusion between the brazing alloy and the base metal was intense,resulting in silicon phase aggregation,and cracks appeared in the weld.With the increase of brazing temperature,the shear strength of the joint first increased and then decreased,and the leakage after welding first decreased and then increased.The best brazing temperature was 570℃,at this time the weld was tightly combined with the base metals on both sides,the elements diffused uniformly,and the joint had the largest shear strength and the best air tightness.

关 键 词：高硅铝合金 可伐合金 Al-Si-Cu-Ni钎料 钎焊温度 抗剪强度 

分 类 号：TG454[金属学及工艺—焊接]