Theory-guided materials design of multiphase alloys with superior stiffness at finite temperatures

0583955 - ÚFM 2025 RIV GB eng J - Journal Article
Huang, J. - Liu, S. - Friák, Martin - Qiu, Ch. - Shang, S.-Li. - Liu, Z.-K. - Du, Y.
Theory-guided materials design of multiphase alloys with superior stiffness at finite temperatures.
Acta Materialia. Roč. 269, May (2024), č. článku 119796. ISSN 1359-6454. E-ISSN 1873-2453
R&D Projects: GA ČR(CZ) GA22-22187S
Institutional support: RVO:68081723
Keywords : Multiphase alloys * Elastic modulus * First-principles * CALPHAD * Mg-Al-Si alloy
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 9.4, year: 2022
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S1359645424001484?via%3Dihub

Aiming at designing Mg alloys with a significantly increased stiffness at elevated temperatures, we propose a
high-precision multi-scale methodology to compute temperature-dependent elastic modulus of homogeneous
multiphase alloys. The proposed method combines (i) first-principles calculations of temperature- and solid
solubility-dependent elastic properties in individual phases with (ii) a two-level multiphase homogenization at
the continuum level and (iii) a phenomenological thermodynamic modeling by the CALPHAD approach. According to the post-average approximation during the calculation, the stresses and strains of individual phases in the alloy are superimposed before undergoing the average approximation. This is different from the traditional method which consider forces as acting axially assumptions of isostrain and isostress model and followed by
numerical averaging. We applied the proposed method in light-weight Mg-alloys, in particular, a three-phase alloy with the composition Mg0.878Al0.083Si0.039, and verified it through experimental measurements. The present work identifies that MgxAlySi1-x-y with 0 ≤ x ≤ 0.87 and 0 ≤ y ≤ 0.87-x are candidate compositions with
Young’s modulus exceeding 60 GPa at 623 K.
Permanent Link: https://hdl.handle.net/11104/0352713