Xu, Y., Lu, X., Yang, X., Li, W., Aitken, Z., Vastola, G., Gao, H., & Zhang, Y.-W. (2024). Temperature-dependent, multi-mechanism crystal plasticity reveals the deformation and failure behaviour of multi-principal element alloys. Journal of the Mechanics and Physics of Solids, 185, 105549. https://doi.org/10.1016/j.jmps.2024.105549
Abstract:
In this work, we have developed a temperature-dependent, multi-mechanism crystal plasticity
(CP) model aimed at unravelling the deformation and failure resistance of Cantor alloy-like multi-
principal element alloys (MPEA) under both uniaxial tensile and cyclic loading conditions. Three
deformation mechanisms: dislocation slip, deformation twinning, and phase transformation are
considered under a unified stress-driven, thermally activated law. In addition, the effect of short-
range ordering (SRO) is introduced by accounting for the inhomogeneous distributions of material
properties within individual grains. Our work yields the following key findings: (1) The
rate- and temperature-sensitivity of the materials, such as the occurrence and sequence of
dislocation slip, deformation twinning, and martensitic phase transformation observed in experiments
can be captured through the calibrated material properties. (2) The enhancement of the
mechanical response of the Cantor alloy-like MPEAs due to the SRO effect is intrinsically linked to
the generation of geometrically necessary dislocations resulting from localized variations in
material properties. (3) The excellent fatigue and fracture resistance exhibited by Cantor alloy-
like MPEAs at low temperatures can be attributed to the homogenization of stored energy density
within the microstructure. This homogenization arises from the development of deformation
twinning and martensitic phase transformation. Our newly developed CP model and the key
findings provide a valuable guide for the design of MPEAs to achieve superior fatigue and fracture
resistance without compromising their inherent strength.
License type:
Attribution 4.0 International (CC BY 4.0)
Funding Info:
This research / project is supported by the A*STAR - MTC Programmatic Funding
Grant Reference no. : M22L2b0111
This research / project is supported by the A*STAR - AME Programmatic Fund
Grant Reference no. : A1898b0043