Why do cracks occur in the weld joint of Ti-22Al-25Nb alloy during post-weld heat treatment?
oleh: Ling Shao, Ling Shao, Ling Shao, Xinyu Zhang, Yingwei Chen, Liu Zhu, Liu Zhu, Sujun Wu, Qijie Liu, Weiwei Li, Weiwei Li, Na Xue, Na Xue, Zhibiao Tu, Zhibiao Tu, Tianle Wang, Jitang Zhang, Jitang Zhang, Sheng Dai, Sheng Dai, Xinxing Shi, Mengliang Chen
| Format: | Article |
|---|---|
| Diterbitkan: | Frontiers Media S.A. 2023-03-01 |
Deskripsi
Ultrasonic pulse frequency tungsten inert gas welding technology was adopted to join Ti-22Al-25Nb alloy. There were some cracks in the Ti-22Al-25Nb alloy weld joint after post-weld heat treatment. The hardness and Young’s modulus of α2, O, and β/B2 phases in Ti-22Al-25Nb alloy were examined with an in situ nanoindentation technique. The phase transition stresses of three different phases in the weld joint of Ti-22Al-25Nb alloy were analyzed to explain why cracks occur in the weld joint of Ti-22Al-25Nb alloy during post-weld heat treatment. The results show that mean hardness is highest for the α2 phase, second-highest for the O phase, and lowest for the β/B2 phase; the mean Young’s modulus has the same trend in Ti-22Al-25Nb alloy. Phase transition stress results in cracks in the weld joint of Ti-22Al-25Nb alloy during post-weld heat treatment. By improving post-weld heat treatment, the ultimate strength of the Ti-22Al-25Nb alloy weld joints reaches 750 MPa, which is 72.5% that of the base material.