Microstructures and high-temperature properties of TC4 titanium alloy joints welded by electron beam

The microstructures and high-temperature properties of TC4 titanium alloy joints welded by the electron beam were investigated by high-temperature tensile test, high-temperature endurant tensile test and metallographic examination.The results showed that the joint of TC4 alloy with good performance at hightemperature can be obtained by means of electron beam welding. The high-temperature tensile strength of welded joint was 630 MPa, almost the same with that of the base metal.The endurant tensile strength of welded joint under 400℃ for 100 h was greater than 600 MPa, not less than that of the base metal.The microstructure of the weld is α'phase (needle martensite) which is transformed from the primary β matrix.The grain size of theweld which were obtained after high-temperature tensile test and high-temperature endurant tensile test becomes larger than that of weld at room-temperature, but the growth degree of the grain was not dependent on the high-temperature duration.