| 摘要: |
| 焊接接头晶粒粗大以及较浅的焊缝熔深一直是困扰钛合金TIG焊的难题，为解决这一难题，本实验通过控制超声辐射能量，探究了超声同轴辅助TIG(U-TIG) 方法对TC4钛合金焊缝的成形、显微组织和力学性能的影响。结果表明，施加超声后，焊接接头的性能得到了显著改善。U-TIG焊缝的熔深最高可达1.34 mm，相比TIG提升了112.7%。此外，焊缝的显微硬度和强度最高可达553 HV和1244.72 MPa，相比TIG分别提升了44.7%和17%。在常规TIG焊中，焊缝晶粒主要为粗大的柱状晶，当超声功率达到1200 W时，焊缝晶粒由柱状晶转变为细小的等轴晶。超声波的压缩效应使电弧的能量集中，从而提高了焊缝的熔深，超声空化和声流效应在细化焊缝晶粒方面发挥了重要作用，从而提高了焊缝强度。 |
| 关键词: TC4钛合金 U-TIG 显微组织 力学性能 |
| 基金项目:国家自然科学基金（523***62） |
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| Effect of Ultrasonic Radiation Energy on Microstructure and Mechanical Properties of TC4 Titanium Alloy TIG Welded Joints |
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Gao Yihao1, Ren Boqiao1, Bi Fenghua2, Chen Yunhao1, Sui Xinchen1, Chen Chao1
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1. School of Materials Science and Engineering, Jilin University, Changchun 130025;2. China Academy of Agricultural Mechanization Science and Research Group Co., Ltd., Beijing 100080
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| Abstract: |
| The coarse grain size and shallow weld penetration in welded joints have always been a challenge for titanium alloy TIG welding. To solve this problem, this work investigates the influence of ultrasonic coaxial assisted TIG (U-TIG) method on the formation, microstructure, and mechanical properties of TC4 titanium alloy weld seams by controlling ultrasonic radiation energy. The results show that the comprehensive properties of the welded joint are significantly improved after applying ultrasound. The maximum penetration depth of U-TIG weld seam reaches
1.34 mm, which is 112.7% higher than TIG. In addition, the microhardness and tensile strength of the weld joint reach up to 553 HV and 1244.72 MPa, which are 44.7% and 17% higher than TIG, respectively. In conventional TIG welding, the grain of the weld seam is mainly coarse columnar crystals. When the ultrasonic power reaches 1200 W, the grains of the weld seam change from columnar crystals to fine equiaxed crystals. The compression effect of ultrasound concentrates the energy of the arc, thereby improving the penetration depth of the weld. Ultrasonic cavitation and acoustic streaming effects play an important role in refining the grain size of the weld, thereby improving the strength of the weld. |
| Key words: TC4 alloy U-TIG microstructure mechanical properties |
