Abstract
It is known that nanoscale precipitates strongly affect the precipitation hardening of structural materials. In this study, we report the precipitation kinetics and thermostability of Cu-rich and NiAl nanoprecipitates in nanostructured steels with Mo additions. Atom probe tomography and first-principles calculations revealed that the addition of Mo effectively decreased the diffusion coefficients of Cu, Ni and Al atoms, leading to the change in the precipitation mechanisms from NiAl prior-precipitation with an instantaneous-nucleation mechanism to the Cu prior-precipitation with a continuous-nucleation mechanism. The decreased diffusion coefficient significantly improves the thermostability of nanoprecipitates and strongly enhances the strength of the nanostructured steels.
Original language | English |
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Pages (from-to) | 187-194 |
Number of pages | 8 |
Journal | Materials Research Letters |
Volume | 8 |
Issue number | 5 |
DOIs | |
Publication status | Published - 3 May 2020 |
Keywords
- Mo additions
- Nanoprecipitates
- nanostructured steels
- precipitation mechanisms
- thermostability
ASJC Scopus subject areas
- Materials Science(all)