摘要
Ti_(2)AlNb与GH4169合金的可靠连接对降低飞行器重量、提高飞行效率,并拓展Ti_(2)AlNb合金的应用范围有重要意义。针对钛铝系合金与镍基高温合金焊后接头易产生较大残余应力和多种TiNi脆性金属间化合物的问题,本研究基于界面相容性原则设计了类Ti元素与类Ni元素接近1∶1的(TiZrHf)_(50)(Ni Cu)_(45)Al_(5)高熵非晶钎料,研究不同钎料成分和钎焊温度对Ti_(2)AlNb与GH4169合金钎焊接头界面组织及性能的影响规律。结果表明:(TiZrHf)_(50)(NiCu)_(45)Al_(5)钎料钎焊接头典型界面组织为Ti_(2)AlNb合金/B2+固溶了Ni和Cu元素的Ti_(2)AlNb相(Ⅰ区)/(Ti,Zr,Hf)(Ni,Cu,Al)_(2)+(Ti,Zr,Hf)(Ni,Cu)_(2)(Ⅱ区)/(Ni,Cr,Fe,Ti)ss+(Ni,Cr,Fe)_(ss)(Ⅲ区)/GH4169合金。钎料成分和钎焊温度分别对钎缝Ⅱ区反应物相形成与反应物相组织演变有较大影响。采用(TiZrHf)_(30)(NiCu)_(65)Al_(5)钎料钎缝Ⅱ区主要由(Ti,Zr)(Ni,Cu,Al)_(2)相、Al(Ni,Cu)_(2)Ti相和Ti(Ni,Cu)_(2)相组成,采用(TiZrHf)_(40)(NiCu)55Al_(5)钎料钎缝Ⅱ区主要为(Ti,Zr,Hf)(Ni,Cu)相。随钎焊温度升高,钎缝Ⅱ区厚度呈现先减小后增加的趋势。采用(TiZrHf)_(50)(NiCu)_(45)Al_(5)钎料钎焊接头在1035℃/15 min时剪切强度达到最大为_(30)5 MPa。断裂主要发生在母材与钎料的界面处,随钎焊温度升高,接头断裂位置逐渐转移至钎缝Ⅱ区,断口形貌为典型的解理断裂特征。钎焊接头界面组织的形成机理可划分为原子的固态扩散、液相生成与冶金反应、等温扩散凝固和反应物相生长与演变四个阶段。
Sound joining of Ti_(2)AlNb alloy to GH4169 alloy is crucial for reducing the weight of aircraft,enhancing flight efficiency,and expanding the application range of Ti_(2)AlNb alloy.Addressing the issue of significant residual stresses and the formation of various brittle TiNi intermetallic compounds in joints between titanium-aluminum alloys and nickel-based superalloys after welding,this study designed a high-entropy amorphous brazing filler with an approximate 1∶1 ratio of Ti-group elements to Ni-group elements,specifically(TiZrHf)_(50)(NiCu)_(45)Al_(5),based on the principle of interfacial compatibility.The research focused on the effects of different brazing filler compositions and brazing temperatures on the interfacial microstructure and properties of brazed joints between Ti_(2)AlNb and GH4169 alloys.The results indicated that the typical interfacial structure of brazed joints using(TiZrHf)_(50)(NiCu)_(45)Al_(5)consisted of Ti_(2)AlNb alloy/B2 phase dissolved with Ni and Cu(Zone I)/(Ti,Zr,Hf)(Ni,Cu,Al)_(2)+(Ti,Zr,Hf)(Ni,Cu)_(2)(Zone II)/(Ni,Cr,Fe,Ti)ss+(Ni,Cr,Fe)_(ss)(Zone III)/GH4169 alloy.The composition of the brazing filler and the brazing temperature significantly influenced the formation and evolution of reactive phases in Zone II of the brazed seam.Using(TiZrHf)_(30)(NiCu)_(65)Al_(5),Zone II primarily consisted of(Ti,Zr)(Ni,Cu,Al)_(2),Al(Ni,Cu)_(2)Ti,and Ti(Ni,Cu)_(2)phases,while using(TiZrHf)_(40)(NiCu)55Al_(5),Zone II predominantly featured(Ti,Zr,Hf)(Ni,Cu)phases.As the brazing temperature increased,the thickness of Zone II first decreased and then increased.Brazed joints using(TiZrHf)_(50)(NiCu)_(45)Al_(5)reached a maximum shear strength of_(30)5 MPa at 1035℃for 15 min.Fracture primarily occurred at the interface between the base material and the brazing filler,and with increasing brazing temperature,the fracture location gradually shifted to Zone II,displaying typical cleavage fracture characteristics.The formation mechanism of the joint interface structure could be categorized into four stages:solid-state diffusion of atoms,formation of liquid phase and metallurgical reactions,isothermal diffusion solidification,and growth and evolution of reactive phases.
作者
张振阳
王景宽
李鹏
王银晨
李超
张亮亮
董红刚
ZHANG Zhenyang;WANG Jingkuan;LI Peng;WANG Yinchen;LI Chao;ZHANG Liangliang;DONG Honggang(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2024年第22期116-129,共14页
Journal of Mechanical Engineering
基金
国家重点研发计划(2023YFB3407500)
国家自然科学基金面上(52075074,52375313)资助项目。
关键词
异种材料连接
钎料设计
钎焊
界面组织
力学性能
dissimilar material joining
design of filler metal
brazing
interface microstructure
mechanical properties
