Feasibility study on feeding wire electron beam brazing of pure titanium using an electron gun for space welding

• Published in: Vacuum Vol. 180; p. 109575
• Main Authors: Ting, Wang, Yifan, Wang, Chong, Gao, Siyuan, Jiang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2020
• Subjects: AgCu28 filler wire; Microstructure; Pure titanium TA2; Vacuum electron beam brazing; AgCu28 filler wire; Pure titanium TA2; Microstructure; Vacuum electron beam brazing
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2020.109575

Vacuum electron beam brazing experiments of pure titanium TA2 with automated feeding AgCu28 wire as filler metal were carried out. The beam current and the welding speed could affect the welding heat inputs to affect the surface appearances, the microstructures and the tensile strengths of the brazed welds. The typical chemical microstructures of the brazed welds were composed of Ag-based solid solution, Ti2Cu and TiCu, meanwhile, α-Ti would exist at the interface under the higher beam current. Moreover, the higher welding speed would promote the loss of Ag-based solid solution. Both the uniform distribution of granular Ag-based solid solution and the existence of α-Ti phase could improve the tensile strength of the brazed joint. It implied that the new electron beam gun designed for space welding was dependable for brazing in the open space. It provides experience for the connection of titanium and titanium alloys in the space and provides the theoretical and experimental basis for its application in the space industry. •The joining of TA2 to the other by feeding wire electron beam brazing using an electron gun for space welding is possible.•Vacuum electron beam brazing avoids the oxidation of Ag–Cu filler metal in the welding process.•The variation of Ti–Cu compounds in brazed welds with the change of welding heat inputs was described.•The causes of Ag loss in brazed welds and its effect on mechanical properties of welds were expounded.