Grain refinement and Laves phase dispersion by high-intensity ultrasonic vibration in laser cladding of Inconel 718

Autor: Jian Chen, Zhehe Yao, Fabo Wang, Yiming Chi, Zhen Wang, Szymon Tofil, Jianhua Yao
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Journal of Materials Research and Technology, Vol 30, Iss , Pp 8563-8575 (2024)
Druh dokumentu: article
ISSN: 2238-7854
DOI: 10.1016/j.jmrt.2024.05.229
Popis: Laser cladding is a promising surface modification and repair technology for fabricating Inconel 718 parts. However, laser cladding may produce coarse grains and brittle Laves phase, leading to a significant decrease in performance. The application of high-intensity ultrasonic vibration in laser cladding is able to refine grain and reduce Laves phase. This study investigates the distribution characteristics and the evolution mechanism of the grains and Laves phase in laser cladding with high-intensity ultrasonic vibration. The effects of high-intensity ultrasonic vibration on alteration of grain characteristics and the reduction of Laves phase were analyzed and discussed through ultrasonic vibration-assisted laser cladding experiments. Results indicate that high-intensity ultrasonic vibration promoted a columnar-to-equiaxed transition, and reduced the grain size from 75.6 μm to 48.8 μm. Furthermore, the Laves phase had a decrease of 47.1% in the volume fraction, and transformed from a long-striped shape into a fine granular shape, leading to a more homogeneous distribution of elements in Laves phase. The change in the grains and the Laves phase is attributed to dendrite fragmentation and inhibition of element segregation by nonlinear effects of ultrasound including cavitation and acoustic streaming. The findings of this study confirm the significant benefits of applying high-intensity ultrasonic vibration in laser cladding and provide insight into the underlying evolution mechanisms of high-intensity ultrasonic vibration for grains and Laves phase.
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