Infrared Brazing of Ti50Ni50 Shape Memory Alloy and Inconel 600 Alloy with Two Ag-Cu-Ti Active Braze Alloys

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2017-02, Vol.48 (2), p.735-744
• Main Authors: Shiue, Ren-Kae, Wu, Shyi-Kaan, Yang, Sheng-Hao
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Materials Science; Metallic Materials; Nanotechnology; Structural Materials; Surfaces and Interfaces; Thin Films
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-016-3890-z

Infrared brazing of Ti 50 Ni 50 SMA and Inconel 600 alloy using Cusil-ABA and Ticusil filler metals has been investigated. The joints were dominated by Ag-Cu eutectic with proeutectic Cu in the Cusil-ABA brazed joint and with proeutectic Ag in the Ticusil one. A continuous curved belt composed of a Ni 3 Ti layer and a (Cu x Ni 1− x ) 2 Ti layer formed in the brazed Ti 50 Ni 50 /Ticusil/Inconel 600 joint. On the Ti 50 Ni 50 SMA side, an intermetallic layer of (Cu x Ni 1− x ) 2 Ti formed in all joints, with x values around 0.81 and 0.47. Layers of (Cu x Ni 1− x ) 2 Ti, Ni 3 Ti, and mixed Ni 3 Ti and Ni 2 Cr intermetallics were observed next to the Inconel 600 substrate in the brazed Ti 50 Ni 50 /Cusil-ABA/Inconel 600 joint. The maximum shear strengths of the joints using the Cusil-ABA filler metal and the Ticusil filler metal were 324 and 300 MPa, respectively. In the Cusil-ABA brazed joint, cracks with cleavage-dominated fracture propagated along the (Cu x Ni 1− x ) 2 Ti interfacial layer next to the Ti 50 Ni 50 SMA substrate. In the Ticusil brazed joint, ductile dimple fracture occurred in the Ag-rich matrix near the Inconel 600 alloy substrate. The absence of a detrimental Ti-Fe-(Cu) layer on the Inconel 600 substrate side can effectively improve the shear strength of the joint.