Contact reaction brazing of TiAl alloy with Ti-Zr-V-Nb-Cu-Ni-Mn system high-entropy alloy filler metal
摘要
For the requirement of high-temperature-resistant TiAl joints, a high-entropy alloy filler composition of Ti-Zr-V-Nb-Cu-Ni-Mn was designed. It showed that the microstructure of the filler alloy was mainly composed of (Ti,Zr,Nb,V)-(Ni,Cu,Mn) intermetallic compound and (Ti,V,Nb)ss dissolved with Mn. Furthermore, TiAl alloy was joined at 1070 ℃, 1100 ℃, and 1130 ℃ for 5 min with single and double foils separately. The joint microstructures were mainly composed of gray (Ti,Nb,V)-Al phases in the middle region, (Ti,Zr,Nb,V)-(Ni,Cu,Mn)-Al phases near the base metal, and dark gray Ti-Al complex phases with few Nb, V, and other elements. The mechanism of microstructural evolution with the brazed joint was analyzed. In addition, the mechanical property was tested and the relationship between the joint microstructure and properties was discussed.