TY - JOUR

T1 - A Sharp-Interface Model of the Diffusive Phase Transformation in a Nickel-Based Superalloy

AU - Munk, Lukas

AU - Reschka, Silvia

AU - Maier, Hans Jürgen

AU - Wriggers, Peter

AU - Löhnert, Stefan

N1 - Funding Information: This work was supported by the LUH compute cluster, which is funded by the Leibniz Universität Hannover, the Lower Saxony Ministry of Science and Culture (MWK), and the German Research Association (DFG). Funding Information: The authors gratefully acknowledge financial support by Deutsche Forschungsgemeinschaft (DFG) through grant no. 282253287. The publication of this article was funded by the Open Access Fund of Leibniz Universität Hannover.

PY - 2022/8

Y1 - 2022/8

N2 - A sharp-interface model employing the extended finite element method is presented. It is designed to capture the prominent (Formula presented.) - (Formula presented.) phase transformation in nickel-based superalloys. The novel combination of crystal plasticity and sharp-interface theory outlines a good modeling alternative to approaches based on the Cahn–Hilliard equation. The transformation is driven by diffusion of solute (Formula presented.) -forming elements in the (Formula presented.) -phase. Boundary conditions for the diffusion problem are computed by the stress-modified Gibbs–Thomson equation. The normal mass balance of solute atoms at the interface yields the normal interface velocity, which is integrated in time by a level set procedure. In order to capture the influence of dislocation glide and climb on interface motion, a crystal plasticity model is assumed to describe the constitutive behaviour of the (Formula presented.) -phase. Cuboidal equilibrium shapes and Ostwald ripening can be reproduced. According to the model, in low (Formula presented.) volume-fraction alloys with separated (Formula presented.) -precipitates, interface movement does not have a significant effect on tensile creep behaviour at various lattice orientations.

AB - A sharp-interface model employing the extended finite element method is presented. It is designed to capture the prominent (Formula presented.) - (Formula presented.) phase transformation in nickel-based superalloys. The novel combination of crystal plasticity and sharp-interface theory outlines a good modeling alternative to approaches based on the Cahn–Hilliard equation. The transformation is driven by diffusion of solute (Formula presented.) -forming elements in the (Formula presented.) -phase. Boundary conditions for the diffusion problem are computed by the stress-modified Gibbs–Thomson equation. The normal mass balance of solute atoms at the interface yields the normal interface velocity, which is integrated in time by a level set procedure. In order to capture the influence of dislocation glide and climb on interface motion, a crystal plasticity model is assumed to describe the constitutive behaviour of the (Formula presented.) -phase. Cuboidal equilibrium shapes and Ostwald ripening can be reproduced. According to the model, in low (Formula presented.) volume-fraction alloys with separated (Formula presented.) -precipitates, interface movement does not have a significant effect on tensile creep behaviour at various lattice orientations.

KW - crystal plasticity

KW - diffusion

KW - phase transformation

KW - sharp-interface theory

KW - XFEM

UR - http://www.scopus.com/inward/record.url?scp=85137763793&partnerID=8YFLogxK

U2 - 10.3390/met12081261

DO - 10.3390/met12081261

M3 - Article

AN - SCOPUS:85137763793

VL - 12

JO - Metals

JF - Metals

SN - 2075-4701

IS - 8

M1 - 1261

ER -