Specially Structured AgCuTi Foil Enables High-Strength and Defect-Free Brazing of Sapphire and Ti6Al4V Alloys: The Microstructure and Fracture Characteristics
Shaohong Liu,
Hairui Liu,
Limin Zhou,
Hao Cui,
Manmen Liu,
Li Chen,
Ming Wen,
Haigang Dong,
Feng Liu,
Wei Wang,
Song Li
Affiliations
Shaohong Liu
Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
Hairui Liu
Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
Limin Zhou
State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Yunnan Precious Metals Laboratory Co., Ltd., Kunming 650106, China
Hao Cui
State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Yunnan Precious Metals Laboratory Co., Ltd., Kunming 650106, China
Manmen Liu
State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Yunnan Precious Metals Laboratory Co., Ltd., Kunming 650106, China
Li Chen
State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Yunnan Precious Metals Laboratory Co., Ltd., Kunming 650106, China
Ming Wen
State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Yunnan Precious Metals Laboratory Co., Ltd., Kunming 650106, China
Haigang Dong
State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Yunnan Precious Metals Laboratory Co., Ltd., Kunming 650106, China
Feng Liu
State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Yunnan Precious Metals Laboratory Co., Ltd., Kunming 650106, China
Wei Wang
Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
Song Li
Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
A novel AgCuTi brazing foil with a unique microstructure was developed, which could achieve strong vacuum brazing of Ti6Al4V (TC4) and sapphire. The brazing foil was composed of Ag solid solution (Ag(s,s)), Cu solid solution (Cu(s,s)), and layered Ti-rich phases, and had a low liquidus temperature of 790 °C and a narrow melting range of 16 °C, facilitating the defect-free joining of TC4 and sapphire. The sapphire/TC4 joint fabricated by using this novel AgCuTi brazing foil exhibited an outstanding average shear strength of up to 132.2 MPa, which was the highest value ever reported. The sapphire/TC4 joint had a characteristic structure, featuring a brazing seam reinforced by TiCu particles and a thin Ti3(Cu,Al)3O reaction layer of about 1.3 μm. The fracture mechanism of the sapphire/TC4 joint was revealed. The crack originated at the brazing seam with TiCu particles, then propagated through the Ti3(Cu,Al)3O reaction layer, detached the reaction layer from the sapphire, and finally penetrated into the sapphire. This study offers valuable insights into the design of active brazing alloys and reliable metal–ceramic bonding.