The present research exploits diffusion brazing of mechanically alloyed Y 2O_3 dispersion strengthened nick-el-base MA760 and iron-base MA956 alloys using B-and P-containing thin foil and sputter coated interlayers.Mi...The present research exploits diffusion brazing of mechanically alloyed Y 2O_3 dispersion strengthened nick-el-base MA760 and iron-base MA956 alloys using B-and P-containing thin foil and sputter coated interlayers.Microstructures of diffission brazed interface before and after recrystallization annealing were investigated usingoptical metallography, electron microprobe analysis, and transmission electron microscopy. It has been foundthat B and P have a strons influence on the recrystallization behavior of these materials. Too high B or P levelsin the interlayers caused recrystallization of the base alloys during brazing process which was operated at temperatures below normal recrystallization points.展开更多
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 m...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.展开更多
文摘The present research exploits diffusion brazing of mechanically alloyed Y 2O_3 dispersion strengthened nick-el-base MA760 and iron-base MA956 alloys using B-and P-containing thin foil and sputter coated interlayers.Microstructures of diffission brazed interface before and after recrystallization annealing were investigated usingoptical metallography, electron microprobe analysis, and transmission electron microscopy. It has been foundthat B and P have a strons influence on the recrystallization behavior of these materials. Too high B or P levelsin the interlayers caused recrystallization of the base alloys during brazing process which was operated at temperatures below normal recrystallization points.
基金supported by the National Natural Science Foundation of China (Grant No. 51574177)the China Natural Founds for Distinguished Young Scientists (Grant No. 51325401)the National High Technology Research and Development Program of China (“863” Program, Granted No. 2015AA042504)
文摘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.
