On development of NiMo-SiC alloys via powder metallurgy for the use in molten salt environment
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Date
2017-11-27
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Publisher
Engineers Australia
Abstract
A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt environment, namely in future molten salt reactors (MSR), and concentrating solar power (CSP) plants. In the current study, a battery of NiMo-based alloys containing varying amounts of SiC (0.5-2.5 wt%) were prepared by mechanical alloying from Ni-Mo-SiC powder mixture, The mechanical alloying was followed by spark plasma sintering and rapid cooling. Neutron Powder Diffraction (NPD), Electron Back Scattering Diffraction (EBSD) and Transmission Electron Microscopy (TEM) were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC alloys. The present study shows that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni3Si nano-precipitates provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. In addition, formed Mo2C particles limit the grain growth of NiMo matrix thus further increasing the strength of these NiMo-SiC via Hall-Petch strengthening. As a result, these newly developed NiMo-SiC alloys possess superior strength in comparison to conventional forged NiMo alloys. However, it is shown that the cold welding of powders during the mechanical alloying leads to porosity, which might then lead to reduced ductility.© 2017 Engineers Australia
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Keywords
Alloys, Metallurgical effects, Powder metallurgy, Molten salts, Neutron diffraction, Molten salt reactors
Citation
Yang, C., Muránsky, O., Zhu, H., Avdeev, A., Huang, H., Huai, P., & Zhou, X. (2017). On development of NiMo-SiC alloys via powder metallurgy for the use in molten salt environment. Paper presented to the 9th Australasian Congress on Applied Mechanics (ACAM9), University of NSW, Sydney, 27-29 November 2017. In Prusty, G. & Paradowska, A. (eds) 9th Australasian Congress on Applied Mechanics (ACAM9), University of NSW, Sydney, 27-29 November 2017, (pp. 508-515). Retrieved from: https://search.informit.org/doi/10.3316/INFORMIT.393707440721228