Research on Underwater Wet Laser Self-Fusion Welding Process and Analysis of Microstructure and Properties of TC4 Titanium Alloy Weld
In order to explore the feasibility of underwater wet laser welding of the TC4 titanium alloy, research on the underwater laser self-fusion welding process was carried out. The weld structure and mechanical properties in both the air environment and the underwater environment were compared and analy...
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MDPI AG
2022-05-01
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Online Access: | https://www.mdpi.com/1996-1944/15/9/3380 |
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author | Zhihai Cai Xian Du Jialei Zhu Kai Wang Xiaoxin Zhao Jun Liu Jing Li Jian Liu Jia Wang Haidou Wang |
author_facet | Zhihai Cai Xian Du Jialei Zhu Kai Wang Xiaoxin Zhao Jun Liu Jing Li Jian Liu Jia Wang Haidou Wang |
author_sort | Zhihai Cai |
collection | DOAJ |
description | In order to explore the feasibility of underwater wet laser welding of the TC4 titanium alloy, research on the underwater laser self-fusion welding process was carried out. The weld structure and mechanical properties in both the air environment and the underwater environment were compared and analyzed. The results show that increasing the laser power and reducing the welding speed are beneficial to obtain a larger water depth threshold. Off-focus amount has little effect on water depth threshold; when the laser power is 3000 W and the welding speed is 5 mm/s, and the water depth exceeds 7 mm, a continuous weld cannot be formed. Compared with welding in the air, underwater welding has narrower weld width, smaller heat affected zone and finer crystal grains. The weld structure is mainly composed of α′ martensite and secondary acicular α′ phase, it is distributed in a net basket shape and the grain size at the top of the weld is finer. The hardness of the weld center is above 600 HV0.1, and the residual stress of the underwater welding weld is approximately symmetrically distributed. There is a large tensile stress along the welding direction at the weld, reaching 458 MPa. The larger residual tensile stress leads to the decrease of weld tensile strength, the tensile strength and elongation of the middle sample are only 52% and 77% of the base metal. Furthermore, the fracture mode is typical brittle fracture. |
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id | doaj.art-cb7b270146f24b9f91b3cb741cb15f7c |
institution | Directory Open Access Journal |
issn | 1996-1944 |
language | English |
last_indexed | 2024-03-10T03:57:55Z |
publishDate | 2022-05-01 |
publisher | MDPI AG |
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series | Materials |
spelling | doaj.art-cb7b270146f24b9f91b3cb741cb15f7c2023-11-23T08:42:32ZengMDPI AGMaterials1996-19442022-05-01159338010.3390/ma15093380Research on Underwater Wet Laser Self-Fusion Welding Process and Analysis of Microstructure and Properties of TC4 Titanium Alloy WeldZhihai Cai0Xian Du1Jialei Zhu2Kai Wang3Xiaoxin Zhao4Jun Liu5Jing Li6Jian Liu7Jia Wang8Haidou Wang9National Engineering Research Center for Remanufacturing, Army Academy of Armored Forces, Beijing 100072, ChinaNational Engineering Research Center for Remanufacturing, Army Academy of Armored Forces, Beijing 100072, ChinaBeijing Institute of Petrochemical Technology, Beijing 102617, ChinaBeijing Institute of Petrochemical Technology, Beijing 102617, ChinaBeijing Institute of Petrochemical Technology, Beijing 102617, ChinaNational Engineering Research Center for Remanufacturing, Army Academy of Armored Forces, Beijing 100072, ChinaNational Engineering Research Center for Remanufacturing, Army Academy of Armored Forces, Beijing 100072, ChinaNational Engineering Research Center for Remanufacturing, Army Academy of Armored Forces, Beijing 100072, ChinaNational Engineering Research Center for Remanufacturing, Army Academy of Armored Forces, Beijing 100072, ChinaNational Engineering Research Center for Remanufacturing, Army Academy of Armored Forces, Beijing 100072, ChinaIn order to explore the feasibility of underwater wet laser welding of the TC4 titanium alloy, research on the underwater laser self-fusion welding process was carried out. The weld structure and mechanical properties in both the air environment and the underwater environment were compared and analyzed. The results show that increasing the laser power and reducing the welding speed are beneficial to obtain a larger water depth threshold. Off-focus amount has little effect on water depth threshold; when the laser power is 3000 W and the welding speed is 5 mm/s, and the water depth exceeds 7 mm, a continuous weld cannot be formed. Compared with welding in the air, underwater welding has narrower weld width, smaller heat affected zone and finer crystal grains. The weld structure is mainly composed of α′ martensite and secondary acicular α′ phase, it is distributed in a net basket shape and the grain size at the top of the weld is finer. The hardness of the weld center is above 600 HV0.1, and the residual stress of the underwater welding weld is approximately symmetrically distributed. There is a large tensile stress along the welding direction at the weld, reaching 458 MPa. The larger residual tensile stress leads to the decrease of weld tensile strength, the tensile strength and elongation of the middle sample are only 52% and 77% of the base metal. Furthermore, the fracture mode is typical brittle fracture.https://www.mdpi.com/1996-1944/15/9/3380titanium alloyunderwater weldingmechanical propertiesresidual stress |
spellingShingle | Zhihai Cai Xian Du Jialei Zhu Kai Wang Xiaoxin Zhao Jun Liu Jing Li Jian Liu Jia Wang Haidou Wang Research on Underwater Wet Laser Self-Fusion Welding Process and Analysis of Microstructure and Properties of TC4 Titanium Alloy Weld Materials titanium alloy underwater welding mechanical properties residual stress |
title | Research on Underwater Wet Laser Self-Fusion Welding Process and Analysis of Microstructure and Properties of TC4 Titanium Alloy Weld |
title_full | Research on Underwater Wet Laser Self-Fusion Welding Process and Analysis of Microstructure and Properties of TC4 Titanium Alloy Weld |
title_fullStr | Research on Underwater Wet Laser Self-Fusion Welding Process and Analysis of Microstructure and Properties of TC4 Titanium Alloy Weld |
title_full_unstemmed | Research on Underwater Wet Laser Self-Fusion Welding Process and Analysis of Microstructure and Properties of TC4 Titanium Alloy Weld |
title_short | Research on Underwater Wet Laser Self-Fusion Welding Process and Analysis of Microstructure and Properties of TC4 Titanium Alloy Weld |
title_sort | research on underwater wet laser self fusion welding process and analysis of microstructure and properties of tc4 titanium alloy weld |
topic | titanium alloy underwater welding mechanical properties residual stress |
url | https://www.mdpi.com/1996-1944/15/9/3380 |
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