铌合金及其蜂窝钎焊界面组织与力学性能分析  

Microstructure and Mechanical Properties of Brazed Niobium Alloy andHoneycomb Sandwich Structure

作　　者：邓云华 陶军 续润州 孙刚 DENG Yunhua;TAO Jun;XU Runzhou;SUN Gang(Aeronautical Key Laboratory for Welding and Joining Technologies,AVIC Manufacturing Technology Institute,Beijing 100024,China;Key Laboratory on Power Beam Science and Technology,AVIC Manufacturing Technology Institute,Beijing 100024,China)

机构地区：[1]中国航空制造技术研究院,航空焊接与连接技术航空科技重点实验室,北京100024 [2]中国航空制造技术研究院,高能束流加工技术重点实验室,北京100024

出　　处：《材料导报》2024年第S01期386-391,共6页Materials Reports

摘　　要：采用Ti基、Ni基和Nb基三种钎料进行了铌合金板板真空钎焊和铌合金蜂窝真空钎焊试验。采用光学显微镜、扫描电镜分析了铌合金板板钎焊界面和蜂窝钎焊界面组织特征,采用能谱仪分析了钎焊界面物相成分,采用EBSD方法分析了钎焊界面物相分布,并对铌合金板板钎焊复合板和蜂窝钎焊结构的力学性能进行了测试。结果表明:铌合金板板钎焊时,Ti基钎料钎焊界面由固溶体Nb和(Ti,Zr)-(Ni,Cu)化合物组成,Nb基钎料钎焊界面由Co-Nb化合物、Nb的固溶体和Co-Ti化合物组成,而Ni基钎料钎焊时,钎料与铌合金母材扩散反应较弱,钎焊界面主要为凝固钎料,且Ni与Nb的高温线膨胀系数差异较大,钎焊界面存在因热应力带来的微裂纹问题;铌合金蜂窝钎焊时,Ti基钎料在铌合金蜂窝箔材表面润湿铺展性能较差导致钎焊界面钎角欠佳及钎焊界面焊合质量较差;Ni基钎料钎焊时,随着钎焊保温时间的延长,存在钎焊界面溶蚀问题导致钎焊界面焊合质量下降。在保温时间30 min时,Ni基钎料和Nb基钎料钎焊后的铌合金蜂窝界面焊合质量较好;Ni基钎料钎焊蜂窝因界面存在微裂纹,导致钎焊界面强度下降,Nb基钎料钎焊蜂窝力学性能最佳,蜂窝拉脱强度达到7.96 MPa。Niobium alloy plates and niobium alloy honeycomb sandwich structures were vacuum brazed by Ti based,Ni based and Nb based brazing filler metals.The microstructure characteristics of brazed interface were investigated by optical microscope and scanning electron microscope.The phase composition of brazed interface was analyzed by energy dispersive spectrometer.The phase distribution of brazed interface was analyzed by EBSD method.The mechanical properties of brazed niobium alloy plates and brazed honeycomb sandwich structure were tested.Results show that the brazing interface of Ti based filler metal is composed of solid solution Nb and(Ti,Zr)-(Ni,Zr)compound,while the brazing interface of Nb based filler metal is composed of Co-Nb compound,solid solution of Nb and Co-Ti compound.The brazing interface of Ni based filler metal is mainly solidified brazing filler metal because of the weak diffusion reaction between brazing filler metal and niobium alloy base metal,and there are microcracks in the brazing interface resulting from thermal stress due to the large difference of high temperature linear expansion coefficient between Ni and Nb.Poor wetting and spreading performance of Ti based filler metal on the surface of niobium alloy honeycomb foil leads to poor brazing fillet and poor brazed quality of the brazing interface.With the increase of brazing holding time,the erosion of brazing interface exists,which leads to the decrease of the quality of brazing interface.When the holding time is 30 min,the brazed quality of niobium alloy honeycomb sandwich structures brazed by Ni based solder and Nb based solder are better.The tensile strength of niobium alloy honeycomb sandwich structure brazed by Nb based brazing filler metal is 7.96 MPa.As a result of existence of microcracks,the tensile strength of honeycomb sandwich structure brazed by Ni based brazing filler metal is lower than that of Nb based brazing filler metal.

关 键 词：铌合金 蜂窝结构 真空钎焊 界面组织 力学性能 

分 类 号：TG44[金属学及工艺—焊接]