高铌TiAl合金钎焊接头组织和性能研究（英文）  

Microstructure and Joining Properties of High Nb-containing TiAl Alloy Brazed Joints

作　　者：宋晓国[1] 司晓庆 曹健[1] 王志权 赵洪运[1] 冯吉才[1] 

机构地区：[1]哈尔滨工业大学先进焊接与连接国家重点实验室,黑龙江哈尔滨150001

出　　处：《稀有金属材料与工程》2018年第1期52-58,共7页Rare Metal Materials and Engineering

基　　金：National Science and Technology Major Project(2014ZX04001131);National Natural Science Foundation of China(51405099,U1537206);Shanghai Aerospace Science and Technology Innovation Fund(SAST2015045)

摘　　要：采用Ti-28Ni(质量分数,%)共晶钎料在1100℃实现了高铌Ti Al合金(Ti-45Al-8.5Nb-(W,B,Y)(at%),TAN)的真空钎焊连接。钎焊接头的典型界面结构为TAN/τ_3-Al_3Ti_2Ni+B2/α_2-Ti_3Al layer/α_2-Ti_3Al+δ-Ti_2Ni/α_2-Ti_3Al layer/τ_3-Al_3Ti_2Ni+B2/TAN。深入研究了保温时间对钎焊接头界面组织和连接性能的影响。结果表明:Ni元素从熔融钎料向TAN母材的扩散决定了界面组织的演化,随着保温时间的延长促进了扩散层的增厚,同时导致钎缝宽度逐渐减小。接头剪切强度测试结果显示,当保温时间为15 min时,获得的最大接头室温剪切强度和高温(600℃)剪切强度分别是248.6和166.4 MPa。接头断口分析表明在剪切试验中裂纹主要沿着连续的金属间化合物层产生和扩展。High Nb-containing TiA1 alloy （Ti-45A1-8.5Nb-（W, B, Y） （at%）, abbreviated as TAN alloy） was brazed at 1100 ℃ using Ti-28Ni （wt%） eutectic brazing alloy. The typical interracial microstructure was TAN/r3-A13Ti2Ni＋B2/a2-Ti3AI layer/a2-Ti3Al ＋ 6-TiNi/a2-Ti3Al layer/r3-Al3Ti2Ni ＋ B2/TAN. The effects of holding time on interracial microstructure and joining properties of TAN brazed joints were investigated. The results demonstrate that the diffusion of Ni from molten brazing alloy to TAN substrate plays an important role in the interracial microstructure evolution, which results in an increase of diffusion zone and a reduction of brazed seam with the prolongation of holding time. Shear test indicates that the maximum shear strength at room temperature and high temperature （600 ℃） reaches 248.6 MPa and 166.4 MPa, respectively when holding time is 15 min. Fracture analyses reveal that brittle fracture prefers to initiate and propagate in the continuous intermetallic layers during shear test.

关 键 词：TIAL金属间化合物 真空钎焊 界面组织 力学性能 断口 

分 类 号：TG454[金属学及工艺—焊接]