Interface structure and shear strength of brazed joints of TiAl-based alloy to middle-carbon steel
来源期刊：中国有色金属学报(英文版)2003年第z1期
论文作者：FENG Ji-cai(冯吉才) LIU Hui-jie(刘会杰)
文章页码：22 - 25
Key words：interface structure; shear strength; brazing; TiAl-based alloy; carbon steel
Abstract: Vacuum brazing of a TiAl-based alloy to a middle-carbon steel was carried out at 1173K for 0.5-40min with a Ag-Cu filler metal. The formation phases and interface structure of the joints were investigated by SEM, EPMA and XRD, and the joint strength was determined by the shear test method. Three formation phases, Ti(Cu, Al)2, Ag(s.s.) (Ag-based solid solution) and TiC, occurred in the brazing seam, and the interface structure of the joints can be expressed as TiAl/Ti(Cu, Al)2+Ag(s.s.)/Ag(s.s.)/TiC/steel, but TiC does not occur and a small amount of Ag-Cu eutectic exists in the joints brazed for a shorter time. The shear tests show that the room-temperature strength and fracture location of the brazed TiAl/steel joints change with brazing time. When the joint was brazed at 1173K for less than 2min, the shear strength was up to 150MPa and the fracture occurred within the Ti(Cu, Al)2+Ag(s.s.) zone.
FENG Ji-cai(冯吉才), LIU Hui-jie(刘会杰)
(State Key Laboratory of Advanced Welding Production Technology,
Harbin Institute of Technology, Harbin 150001, China)
Abstract:Vacuum brazing of a TiAl-based alloy to a middle-carbon steel was carried out at 1173K for 0.5-40min with a Ag-Cu filler metal. The formation phases and interface structure of the joints were investigated by SEM, EPMA and XRD, and the joint strength was determined by the shear test method. Three formation phases, Ti(Cu, Al)2, Ag(s.s.) (Ag-based solid solution) and TiC, occurred in the brazing seam, and the interface structure of the joints can be expressed as TiAl/Ti(Cu, Al)2+Ag(s.s.)/Ag(s.s.)/TiC/steel, but TiC does not occur and a small amount of Ag-Cu eutectic exists in the joints brazed for a shorter time. The shear tests show that the room-temperature strength and fracture location of the brazed TiAl/steel joints change with brazing time. When the joint was brazed at 1173K for less than 2min, the shear strength was up to 150MPa and the fracture occurred within the Ti(Cu, Al)2+Ag(s.s.) zone.
Key words:interface structure; shear strength; brazing; TiAl-based alloy; carbon steel
