Year: 2025
Type: article
Abstract: Nanotwins (NTs) significantly enhance strength and thermal stability of face-centered cubic (FCC) alloys compared to coarse-grained counterparts. However, alloying elements can affect NT stability at elevated temperatures. We combined molecular dynamics (MD) simulations with a recently developed anisotropic multi-phase phase field model to investigate NT stability in two Ni-based binary alloys: Ni–Cr and Ni–Fe. MD simulations reveal Ni–Fe alloys have higher intrinsic stacking fault energies compared to Ni–Cr alloys across similar solute concentrations. Moreover, solute effects on incoherent twin boundary (ITB) energies differ notably. ITB mobility exhibits Arrhenius behavior within the studied temperature range. Phase field simulations, incorporating MD-derived mobility laws, demonstrate that NT/grain boundary detachment and subsequent detwinning strongly depend on annealing temperature and NT thickness, particularly above 0.4 homologous temperature. These insights aid in designing nanotwinned Ni-based alloys with improved thermal stability and mechanical properties; in particular, additional Cr or Fe content can significantly elevate the onset temperature of NT motion. Graphical abstract
Authors: Yixi Shen, Irene J. Beyerlein
Institution: University of California, Santa Barbara
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,490
Awards: G1110399006, G1141670404, G2232042528, G2760720504, Materials Research Science and Engineering Center at UCSB, G3349485200, G3400352658, G401861217, Collaborative Research: DMREF: Data-Driven Discovery of the Processing Genome for Heterogenous Superalloy Microstructures, G4281768896, MRI: Acquisition of a High Performance Central Computing Facility at University of California Santa Barbara
OpenAlex ID: W4415444425