Microstructure and mechanical properties of Tantalum/Molybdenum laser welding for electron gun

The laser welding test was carried out on the Tantalum(Ta) and Molybdenum(Mo) lap joints for electron gun. The weld surface morphology, microstructure, interface element distribution, fracture morphology, main phase, vibration and electrical property were studied by metallography microscope, scanning electron microscopy, hardness and mechanical properties of joints, X-ray diffraction, electron micro-hardness and tensile test, vibration table and vacuum degasing system. The results indicate that the morphology of welding surface can be improved through the optimised welding parameters and the electron guns survive in continuous high temperature working conditions. The vibration and electrical property test has examined the welding quality for the electron guns. Meanwhile, the reliability of laser welding process in the development, production, and application of microwave tubes has been verified.