Hall–Petch and grain growth kinetics of the low stacking fault energy TRIP Cr40Co40Ni20 multi-principal element alloy
Abstract
The Cr40Co40Ni20 multi-principal element alloy (MPEA) displays a single-phase face centered cubic initial structure, which partially transforms to hexagonal close packed (HCP) phase by transformation-induced plasticity (TRIP) during straining, as evidenced by nanometric HCP lamellae that provide enhanced mechanical properties. This MPEA also exhibits significant yield strength—grain size dependence, given by the high Hall–Petch coefficients (k = 667 MPa/μm−0.5 and σ0 = 299 MPa). The high activation energy for grain growth (QG = 533 kJ/mol) leads to refined grain structures after conventional heat treatments. These features, combined with the large solid solution strengthening of Cr-rich Cr-Co-Ni MPEAs, grant the Cr40Co40Ni20 alloy a great combination of strength and ductility under tension. Finally, an empirical equation is proposed to describe the stacking fault energy (SFE) of Cr-Co-Ni alloys, contributing to the prediction of the acting deformation mechanisms. Such findings highlight the potential of compositional tuning to enhance multiple strength and deformation mechanisms in the Cr-Co-Ni system.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 09, 2021
- Source ID
- 10.1063/5.0057888
Entities
People
- Amy J. Clarke
- Claudio Shyinti Kiminami
- Francisco G Coury
- Gustavo Bertoli
- Lucas B Otani
Organizations
- Colorado School of Mines
- Coordenação de Aperfeicoamento de Pessoal de Nível Superior
- National Council for Scientific and Technological Development
- Office of Naval Research
- São Paulo Research Foundation
- Universidade Federal de São Carlos