CuSn预合金粉芯复合银钎料的润湿铺展机理  

Wetting and spreading mechanism of CuSn pre-alloyed powder-cored composite silver solder

作　　者：钟素娟 秦建 王蒙 崔大田 龙伟民[2,3] ZHONG Sujuan;QIN Jian;WANG Meng;CUI Datian;LONG Weimin(Henan University of Science and Technology,Luoyang,471000,China;State Key Laboratory of Advanced Brazing Metals&Technology,Zhengzhou Research Institute of Mechanical Engineering Co.,Ltd.,Zhengzhou,450000,China;China Academy of Machinery Ningbo Academy of Intelligent Machine Tool Co.,Ltd.,Ningbo,315700,China;North China University of Water Resources and Electric Power,Zhengzhou,450045,China)

机构地区：[1]河南科技大学,洛阳471000 [2]郑州机械研究所有限公司,新型钎焊材料与技术国家重点试验室,郑州450000 [3]中机智能装备创新研究院(宁波)有限公司,宁波315700 [4]华北水利水电大学,郑州450045

出　　处：《焊接学报》2023年第2期16-21,I0003,I0004,共8页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(U2004186);中国机械科学研究总院集团有限公司博士后基金资助项目(AZXJJ2032002).

摘　　要：研究了添加质量分数为30%~70%CuSn预合金粉复合银钎料在T2紫铜基体上的润湿铺展过程,并讨论了CuSn预合金粉复合银钎料在紫铜基体上的润湿铺展机理.结果表明,在与紫铜基体的润湿铺展过程中,初始接触角由30%CuSn的119°降低到70%CuSn的94°.最终接触角由30%CuSn的15°下降到70%CuSn的7°.当粉芯中CuSn合金粉含量为60%时,钎料在铜板上的润湿面积达到530.04 mm^(2),相比于未添加CuSn合金粉时提高了约66%.由于低熔点CuSn预合金粉的前驱润湿作用使复合银钎料表面张力降低,初始接触角和最终接触角随着CuSn预合金粉含量的增加而减小.CuSn预合金粉在钎焊过程中先于BAg30CuZnSn钎料外皮熔化,形成熔融的铜锡液态合金薄层,降低了固液界面张力.随后,熔化的BAg30CuZnSn箔带在先期熔化的铜锡液态薄层上铺展,并与其发生溶质原子的扩散反应,最终形成液态复合钎料.低熔点CuSn预合金粉的加入,使复合银钎料在铜上的润湿性能显著改善.添加40%CuSn预合金粉复合银钎料与铜基体的反应润湿界面均匀致密,其中白色富Ag相互连接,Sn元素主要分布于富Ag相和周围的锡青铜相中.In this paper,the wetting and spreading process of 30%−70%CuSn pre-alloyed powder composite silver solder on T2 copper matrix was studied,and the wetting and spreading mechanism of CuSn pre-alloyed powder composite silver solder on copper matrix was discussed.The results show that the initial contact angle decreases from 119°for 30%CuSn to 94°for 70%CuSn during the wetting and spreading process with the copper substrate.The final contact angle decreased from 15°for 30%CuSn to 7°for 70%CuSn.When the content of CuSn alloy powder in the powder core is 60%,the wetting area of the solder on the copper plate reaches 530.04 mm^(2),an increase of about 66%compared to when no CuSn alloy powder was added.The initial and final contact angles decreased with the increase of CuSn pre-alloy powder content due to the precursor wetting effect of the low melting point CuSn pre-alloy powder,which melted on the outer skin of BAg30CuZnSn brazing material during the brazing process,forming a thin layer of molten CuSn liquid alloy and reducing the solid-liquid interfacial tension.Subsequently,the molten BAg30CuZnSn foil strip spreads over the pre-melted CuSn liquid thin layer and reacts with it by diffusion of solute atoms,eventually forming a liquid composite braze.The addition of the low melting point CuSn pre-alloyed powder improves the wetting performance of the composite silver brazing material on copper significantly.The reaction wetting interface of the composite silver braze with the copper substrate is uniform and dense with the addition of 40%CuSn pre-alloyed powder,where the white Ag-rich phases are interconnected and the Sn elements are mainly distributed in the Ag-rich phase and the surrounding tin bronze phase.

关 键 词：银钎料 CuSn预合金 铺展面积 界面组织 润湿机理 

分 类 号：TG454[金属学及工艺—焊接]