电子枪零件钽钼激光焊接显微结构和性能分析

Microstructures and Properties of Tantalum and Molybdenum Laser Welding for Electron Guns

摘要:

采用脉冲固体激光器电子枪零件钼和钽进行激光焊接工艺试验，利用金相显微镜、扫描电镜、万能材料试验机、电子显微硬度分析仪、X 射线衍射仪、振动台、电子枪真空除气系统等研究了电子枪金属零件焊缝焊接表面成形、接头区域的组织形貌、界面元素分布、断口形貌、显微硬度与接头力学性能、焊接接头物相、电子枪随机振动及工作状态下电性能和热性能。 结果表明，优化焊接参数后焊接的电子枪经受了在微波管中连续高温工作的考验。 振动试验和电子枪性能试验检验了电子枪组件的焊接牢固程度和焊接质量，验证了激光焊接工艺在小批量微波管研制、生产和应用过程中的可靠性。

Abstract:

Tantalum(Ta)/Molybdenum(Mo) dissimilar joint was successfully joined by laser welding process with pure Pt filler wire. The weld surface morphology, microstructure, interface element distribution, fracture morphology, phase structure, electrical performance and environment adaptability were studied by metallography microscope, scanning electron microscopy, hardness and mechanical properties of joints, X-ray diffraction, electron micro-hardness and tensile test, vibrationStable and ultra-high high vacuum system. Laser parameters have profound effects on microstructures of the laser-welded joints. Pores were generated in the weld zone caused by the preferential vaporization of pure Pt filler metal. The weld zone mainly contained TaPt2, TaPt3 and MoPt phase, resulting higher hardness in the weld zone than that of base metal. The joint fracture surface exhibited typical brittle fracture morphology. The electrical property and vibration test had examined the joints welding quality for electron guns. Meanwhile, the reliability of laser welding process in the development, production, and application of microwave tubes had been verified.