Effect of fast-frequency pulsed waveforms on the microstructure and mechanical properties of Ti-6Al-4V alloy welded by FFP-TIG

作者：Wu, Jianwen; Wang, Zhenmin; Lin, Sanbao; Xie, Zhengchao; Xu, Mengjia; Tian, Jiyu^*; Guo, Chunfu^*

来源：Journal of Materials Research and Technology-JMR&T, 2022, 20: 516-531.

DOI：10.1016/j.jmrt.2022.07.126

• Fast-frequency pulsed waveform
• FFP-TIG
• Ti-6Al-4V
• Grain refinement

Ti-6Al-4V alloys have been widely adopted because of their good mechanical properties. TIG welding is a common method for Ti-6Al-4V alloys. However, the high heat input of conventional TIG can lead to a coarsening of grains within Ti-6Al-4V and thus a weaker Ti -6Al-4V weld. This study presents a novel fast-frequency pulsed tungsten inert gas (FFP-TIG) welding technology to fabricate a high-reliability Ti-6Al-4V weld. The effects of fast-frequency pulsed waveforms on microstructures and mechanical properties of Ti-6Al -4V weld samples were uncovered. The arc core diameter of FFP-TIG technology was reduced by 32%-36% compared with that of conventional TIG. The adoption of FFP-TIG decreased the average grain sizes and acicular martensite a0 within the Ti-6Al-4V weld by 47.7% and 40.5%, respectively, which further enhanced the mechanical properties of the corresponding weldments. The hardness, tensile strength, and elongation of Ti-6Al-4V weldments obtained by FFP-TIG were improved by 10.35%, 13.84%, and 304.61% compared with those obtained by conventional TIG, achieving the highest value of 373 HV, 1018.97 MPa, and 4.301%, respectively. This study provides fresh insight into the devel-opment and application of high-reliability titanium alloy weldments commonly used in the aviation industry.

• 单位
  东北大学