Effects of Nb content in Ti–Ni–Nb brazing alloys on the microstructure and mechanical properties of Ti–22Al–25Nb alloy brazed joints
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2017年第7期
论文作者：Y.Wang X.Q.Cai Z.W.Yang D.P.Wang X.G.Liu Y.C.Liu
文章页码：682 - 689
摘 要：Vacuum brazing was successfully used to join Ti–22Al–25Nb alloy using Ti–Ni–Nb brazing alloys prepared by arc-melting. The influence of Nb content in the Ti–Ni–Nb brazing alloys on the interfacial microstructure and mechanical properties of the brazed joints was investigated. The results showed that the interfacial microstructure of brazed joint consisted of B2, O, ?3, and Ti2 Ni phase, while the width of brazing seams varied at different Nb contents. The room temperature shear strength reached359 MPa when the joints were brazed with eutectic Ti40Ni40Nb20 alloy at 1180?C for 20 min, and it was321, 308 and 256 MPa at 500, 650 and 800?C, respectively. Cracks primarily initiated and propagated in ?3compounds, and partially traversed B2+O region. Moreover, the fracture surface displayed typical ductile dimples when cracks propagated through B2+O region, which was favorable for the mechanical properties of the brazed joint.
Y.Wang，X.Q.Cai，Z.W.Yang，D.P.Wang，X.G.Liu，Y.C.Liu
Tianjin Key Lab of Advanced Joining Technology, School of Materials Science and Engineering, Tianjin University
摘 要：Vacuum brazing was successfully used to join Ti–22Al–25Nb alloy using Ti–Ni–Nb brazing alloys prepared by arc-melting. The influence of Nb content in the Ti–Ni–Nb brazing alloys on the interfacial microstructure and mechanical properties of the brazed joints was investigated. The results showed that the interfacial microstructure of brazed joint consisted of B2, O, ?3, and Ti2 Ni phase, while the width of brazing seams varied at different Nb contents. The room temperature shear strength reached359 MPa when the joints were brazed with eutectic Ti40Ni40Nb20 alloy at 1180?C for 20 min, and it was321, 308 and 256 MPa at 500, 650 and 800?C, respectively. Cracks primarily initiated and propagated in ?3compounds, and partially traversed B2+O region. Moreover, the fracture surface displayed typical ductile dimples when cracks propagated through B2+O region, which was favorable for the mechanical properties of the brazed joint.
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