Vacuum brazing TiAl intermetallic to K4169 alloy using amorphous filler metals Ti_(56.25–x)Zr_(x)Ni_(25)Cu1_(8.75)  

作　　者：Liangliang Zhang Honggang Dong Peng Li Shuai Li Baosheng Wu Yueting Ma Libing Huang Chao Li Jiachen Li Yuesen Yang 

机构地区：[1]School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China [2]School of Mechanical Engineering, North China University of Water Resources and Electric Power, Zhengzhou 450045, China

出　　处：《Journal of Materials Science & Technology》2023年第23期217-231,共15页材料科学技术（英文版）

基　　金：supported by the National Natural Science Foun-dation of China(Nos.52275314 and 52075074);the Collaborative Innovation Center of Major Machine Manufacturing in Liaoning.

摘　　要：A series of Ti_(56.25-x)Zr_(x)Ni_(25)Cu1_(8.75)(x=0–25,at.%) filler metals were designed based on a cluster-plus-glue-atom model to vacuum braze TiAl intermetallic to K4169 alloy. The impact of Zr content on the interfacial microstructure and shear strength of joints was examined. And the relationship between the interfacial lattice structure and the fracture behavior of the joint was investigated. The findings reveal a sectionalized characteristic with three reaction zones (Zone I, Zone II and Zone III) in the microstructure of the TiAl intermetallic to K4169 alloy joint. As the Zr content in filler metals increased, the diffusion of Ti transitioned from long-distance to short-distance in Zone I, changing the initial composition from TiNi_(3) /TiNi/NiNb/(Cr, Fe, Ni)SS to NiCrFe/(Cr, Fe, Ni)SS /TiNi. In Zone II, the initial composition altered from TiNi_(3) /TiNi to TiNi/Ti_(2) Ni/TiNi_(3) /TiCu/TiNi. The interface between Zones II and III altered from a non-coherent and semi-coherent interface of TiNi/TiAl/Ti_(3) Al with significant residual stress to a semi-coherent interface of TiNi/TiNi_(3) /TiAl_(2) /Ti_(3) Al with a gradient distribution. The shear strength of the joint initially decreased and then increased. When the Zr content of filler metal was 25 at.%, the shear strength of the joint reached 288 MPa. The crack initiation position changed from non-coherent TiNi/TiAl interface with high angle grain boundaries (HAGBs) and lattice mismatch of 65.86 at.% to a semi-coherent Ti3 Al/TiAl2 interface with a lattice mismatch of 20.07 at.% when the Zr content increased. The brittle fracture was present on the fracture surfaces of all brazed joints.

关 键 词：Vacuum brazing TiAl intermetallic to K4169 alloy brazed joint Ti-Ni based amorphous filler metal EBSD Lattice mismatch 

分 类 号：TG454[金属学及工艺—焊接]