【摘要】 电子束焊接技术正向高压、大功率、长寿命、高稳定性及智能控制方向发展，已成为大厚度钛合金结构制造的理想焊接工艺选择。本文采用高压电子束，对20 mm厚的TA15钛合金进行焊接，系统分析了在相同热输入条件下，100 kV、120 kV和150 kV加速电压对焊接接头的组织与力学性能的影响，探讨了加速电压对焊接过程的热作用机制。结果显示，加速电压影响焊接接头的局部过冷度，随着加速电压的增加，过冷度降低，促进了TA15钛合金中合金元素扩散转变，最终形成细针状α′相和少量片状α相。在150 kV下，TA15钛合金室温塑性提升归因于β相及焊缝大角度晶界含量的增加，增强了合金的塑性变形能力。本文研究结果可为高压大功率电子束焊接大厚度强韧钛合金的工程应用提供理论依据。更多还原

【Abstract】 The development of electron beam welding technology is advancing toward higher voltages,greater power,extended lifespan,improved stability,and intelligent control,positioning it as an ideal welding technique for thick titanium alloy structures.In this study,a high-voltage electron beam was employed to weld 20 mm thick TA15 titanium alloy,systematically analyzing the effects of 100 kV,120 kV,and 150 kV accelerating voltages on the micro structure and mechanical properties of the weld joints under consistent heat input.Additionally,the thermal action mechanisms of accelerating voltages on the welding process were also investigated.The results show that accelerating voltage significantly impacts local undercooling within the weld joint,and as the accelerating voltage increases,the undercooling degree decreases,thereby promoting the diffusion and transformation of alloying elements in TA15 titanium alloy,resulting in the formation of fine needle-like α’ phase and a small amount of lamellar α phase.At 150 kV,the room-temperature ductility of the TA15 titanium alloy was notably improved due to the increased presence of the β-phase and high-angle grain boundaries in the weld,which in turn enhances the alloy’s plastic deformation capacity.These findings offer crucial theoretical insights for the engineering application of high-voltage,high-power electron beam welding in the fabrication of thick and tough titanium alloys.更多还原