Yield strength increase of a CoCrNi medium entropy alloy by interstitial nitrogen doping at maintained ductility

0524466 - ÚFM 2021 RIV GB eng J - Journal Article
Moravčík, I. - Hadraba, Hynek - Li, L. - Dlouhý, Ivo - Raabe, D. - Li, Z.
Yield strength increase of a CoCrNi medium entropy alloy by interstitial nitrogen doping at maintained ductility.
Scripta Materialia. Roč. 178, MAR (2020), s. 391-397. ISSN 1359-6462. E-ISSN 1872-8456
R&D Projects: GA ČR(CZ) GA17-23964S
Institutional support: RVO:68081723
Keywords : Interstitials * Strengthening * Alloying * Tension test * Concentrated solid solution
OECD category: Materials engineering
Impact factor: 5.611, year: 2020
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S1359646219307262

We show that interstitial nitrogen doping improves the tensile properties of a CoCrNi alloy. A material with 0.5 at% interstitial nitrogen was compared to a nitrogen-free CoCrNi alloy. The nitrogen-doped variant has a stable, single-phase face-centered cubic (FCC) lattice structure without nitrides, also after different annealing treatments (800–900 °C, 10 and 30 min). The nitrogen caused an increase in yield strength by 24–33% at identical ductility compared to the nitrogen-free material with similar grain size. The strengthening effect of nitrogen was explained in terms of the simultaneous increase of the lattice friction stress and of the Hall-Petch coefficient.
Permanent Link: http://hdl.handle.net/11104/0308844