Numerical simulation and experimental investigation of the laser cladding processes of Ti6Al4V with coaxial shroud protection

Lyu, P., Li, P. and Jiang, K. (2023) Numerical simulation and experimental investigation of the laser cladding processes of Ti6Al4V with coaxial shroud protection. Journal of Materials Research and Technology, 26, pp. 4133-4150. (doi: 10.1016/j.jmrt.2023.08.163)

Abstract

Laser cladding with coaxial shroud protection offers the possibility to process reactive metals in an open environment. The numerical analysis was performed on the thermal field and dynamics of molten pool with the aim of clarifying the mechanism of the complex effects of the applied extra shielding gas on the resultant microstructure and surface quality of cladding layers of Ti6Al4V. A three-dimensional (3D) computational fluid dynamics (CFD) model was first developed to investigate the extra shielding gas effect on the molten pool. The simulation shows that the extra shielding gas influences both the surface and internal flow field characteristics of the molten pool. The predicted solidification parameters imply fully columnar microstructure in the entire cladding layer. Comparative analysis was then carried out between the numerical simulation and experiments. The electron backscattering diffraction (EBSD) examination reveals that the high cooling rate due to the extra shielding gas inhibits the formation of grain boundary α phase and simultaneously refines the microstructure. The extra shielding gas reduces the surface roughness of cladding layers, and its bunching effect improves the powder utilization. The multi-track cladding experiments reveal that the extra shielding gas can effectively suppress crack formation with a large overlap ratio. This study provides a better understanding of the effect of extra shielding gas flow on molten pool, which helps control and improve the quality of cladding layers.

• Item Type: Articles
• Additional Information: This work was supported by National Natural Science Foundation of China [51475174] and Subsidized Project for Postgraduates’ Innovative Fund in Scientific Research of Huaqiao University.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Li, Dr Peifeng
• Authors: Lyu, P., Li, P., and Jiang, K.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Journal of Materials Research and Technology
• Publisher: Elsevier
• ISSN: 2238-7854
• ISSN (Online): 2214-0697
• Published Online: 21 August 2023
• Copyright Holders: Copyright © 2023 The Author(s).
• First Published: First published in Journal of Materials Research and Technology 26:4133-4150
• Publisher Policy: Reproduced under a Creative Commons license