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Please use this identifier to cite or link to this item: http://repository.iitr.ac.in/handle/123456789/12754
Title: Effect of Nb addition on Fe-7Cr-Nb and Fe-15Cr-Nb metastable alloy formation and their thermal stability
Authors: Suntharavel Muthaiah V.M.
Koch C.C.
Mula, Suhrit
Published in: Materials Research Express
Abstract: Thermal stability of any structural nanomaterial is extremely important for its prospective high temperature applications. Here, we have investigated the influence of Nb content (up to 1at%) on the thermal stability of mechanically alloyed nanocrystalline Fe-Cr alloys for its possible nuclear first wall reactor application. The alloys were prepared by mechanical milling for 25 h in a high purity argon atmosphere (purity <10 ppm O2) at room temperature. The milling was performed in hardened steel grinding media using SPEX 8000M high energy mill and the powder to ball mass ratio was kept at 1:10. Evolution of disordered Fe-Cr-Nb solid solutions has been analyzed through estimating free energy (Gibbs) change as per Toop's model, variation of precise lattice parameter and TEM-SAED study. The Fe-15%Cr-Nb alloys showed effective thermal stability due to the addition of only 0.25%Nb. The crystallite size of the stabilize alloy was ∼58 nm after annealing at 1000 °C. TEM grain size analysis also corroborated the same. The corresponding microhardness value was found to be quite high (7.8 GPa) which also correlated the stabilizing effect. The grain boundary segregation by oversize Nb atoms along with solid solution hardening by Cr is identified to play the pivotal role for such attractive thermal stability. © 2018 IOP Publishing Ltd.
Citation: Materials Research Express (2018), 5(5): -
URI: https://doi.org/10.1088/2053-1591/aac3ab
http://repository.iitr.ac.in/handle/123456789/12754
Issue Date: 2018
Publisher: Institute of Physics Publishing
Keywords: Fe-Cr-Nb nanostructure
grain boundary segregation
microhardness
Toops model
transmission electron microscopy
ISSN: 20531591
Author Scopus IDs: 57202319961
57203364844
12783902100
Author Affiliations: Suntharavel Muthaiah, V.M., Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Uttarakhand Roorkee, 247667, India
Koch, C.C., Department of Materials Science and Engineering, NC State University, 911 Partner's Way, Raleigh, NC 27606, United States
Mula, S., Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee, Uttarakhand Roorkee, 247667, India
Appears in Collections:Journal Publications [MT]

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