Brazing of TC4 Alloy Using Ti-Zr-Ni-Cu-Sn Amorphous Braze Fillers
Zhan Sun,
Boyu Zhang,
Degang Li,
Xinxin Zhu,
Qing Chang,
Bo Zhang,
Lixia Zhang,
Weimin Long,
Sujuan Zhong
Affiliations
Zhan Sun
State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin 150001, China
Boyu Zhang
State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin 150001, China
Degang Li
State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin 150001, China
Xinxin Zhu
State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin 150001, China
Qing Chang
State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin 150001, China
Bo Zhang
State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin 150001, China
Lixia Zhang
State Key Laboratory of Precision Welding & Joining of Materials and Structures, Harbin 150001, China
Weimin Long
State Key Laboratory of Advanced Brazing Filler Metals & Technology, Zhengzhou Research Institute of Mechanical Engineering Co., Ltd., Zhengzhou 450001, China
Sujuan Zhong
State Key Laboratory of Advanced Brazing Filler Metals & Technology, Zhengzhou Research Institute of Mechanical Engineering Co., Ltd., Zhengzhou 450001, China
In order to address the issues of excessive brittle intermetallic compounds (IMC) formation in the TC4 brazed joints, two types of novel Ti-Zr-Cu-Ni-Sn amorphous braze fillers were designed. The microstructure and shear strength of the TC4/Ti-Zr-Ni-Cu-Sn/TC4 brazed joints were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometer (XRD) and electronic universal materials testing machine. The results show that the optimized Ti35Zr25Ni15Cu20Sn5 braze filler whose chemical composition is closer to the eutectic point possesses a lower melting point compared with the equiatomic Ti23.75Zr23.75Ni23.75Cu23.75Sn5. This was beneficial to the sufficient diffusion of Cu and Ni elements with the base metal during brazing and reduces the residual (Ti,Zr)2(Ni,Cu) content in the joint, which helps to improve the joint performance. The room-temperature and high-temperature shear strength of the TC4 brazed joints using the near eutectic component Ti35Zr25Ni15Cu20Sn5 filler reached a maximum of 472 MPa and 389 MPa at 970 °C/10 min, which was 66% and 48% higher than that of the TC4 joints brazed with the equiatomic Ti23.75Zr23.75Ni23.75Cu23.75Sn5 braze filler. Microstructural evolution and the corresponding mechanical response were in-depth discussed.
