TiZrNiCu非晶钎料钎焊TiBw/TC4复合材料和Ti60合金

摘要

使用TiZrNiCu非晶钎料成功实现了TiBw/TC4复合材料和Ti60合金的钎焊连接.通过扫描电子显微镜、能谱仪、X射线衍射仪及万能材料试验机表征钎焊接头的组织及性能.在940℃保温10 min下,钎焊接头的典型界面组织为TiBw/TC4复合材料/β-Ti+TiB晶须/(Ti,Zr)2(Ni,Cu)金属间化合物层/β-Ti层/Ti60合金.钎焊过程中元素向母材中的扩散过程直接影响接头界面结构.钎焊温度的升高使(Ti,Zr)2(Ni,Cu)金属间化合物层的厚度减小,当钎焊温度超过1020℃时,(Ti,Zr)2(Ni,Cu)金属间化合物层消失.钎焊温度较低时,生成的脆性相(Ti,Zr)2(Ni,Cu)不利于接头性能.接头剪切强度随钎焊温度的升高呈先增加后降低的趋势,在1020℃下获得最大的剪切强度368.6 MPa;而当钎焊温度达到1060℃时,接头强度降低,这是由于形成了粗大的层状(α+β)-Ti组织.%TiBw/TC4 composite was brazed to Ti60 alloy successfully using TiZrNiCu amorphous filler alloy, and the interfacial microstructures and mechanical properties were characterized by SEM, EDX, XRD and universal tensile testing machine. The typical interfacial microstructure was TiBw/TC4 composite/β-Ti + TiB whiskers/ (Ti,Zr)2(Ni,Cu) intermetallic layer/β-Ti/ Ti60 alloy when being brazed at 940 ℃ for 10 min. The interfacial microstructure evolution was influenced strongly by the diffusion and reaction between molten fillers and the substrates. Increasing brazing temperature decreased the thickness of brittle (Ti,Zr)2(Ni,Cu) intermetallic layer, which disappeared finally when the brazing temperature exceeded 1020 ℃. Fracture analyses indicated that cracks were initialized in the brittle intermetallic layer when (Ti,Zr)2(Ni,Cu) phase existed in the brazing seam. The maximum average shear strength of joints reached 368.6 MPa when brazing was conducted at 1020 ℃. Further increasing brazing temperature to 1060 ℃, the shear strength was decreased due to the formation of coarse lamellar (α+β)-Ti structure.