TY - JOUR
T1 - Stochastic 3D microstructure modeling of twinned polycrystals for investigating the mechanical behavior of γ-TiAl intermetallics
AU - Rieder, Philipp
AU - Neumann, Matthias
AU - Monteiro Fernandes, Lucas
AU - Mulard, Aude
AU - Proudhon, Henry
AU - Willot, François
AU - Schmidt, Volker
N1 - Publisher Copyright:
© 2024 The Author(s)
PY - 2024/4
Y1 - 2024/4
N2 - A stochastic 3D microstructure model for polycrystals is introduced which incorporates two types of twin grains, namely neighboring and inclusion twins. They mimic the presence of crystal twins in γ-TiAl polycrystalline microstructures as observed by 3D imaging techniques. The polycrystal grain morphology is modeled by means of Voronoi and –more generally– Laguerre tessellations. The crystallographic orientation of each grain is either sampled uniformly on the space of orientations or chosen to be in a twinning relation with another grain. The model is used to quantitatively study relationships between morphology and mechanical properties of polycrystalline materials. For this purpose, full-field Fourier-based computations are performed to investigate the combined effect of grain morphology and twinning on the overall elastic response. For γ-TiAl polycrystallines, the presence of twins is associated with a softer response compared to polycrystalline aggregates without twins. However, when comparing the influence on the elastic response, a statistically different polycrystalline morphology has a much smaller effect than the presence of twin grains. Notably, the bulk modulus is almost insensitive to the grain morphology and exhibits much less sensitivity to the presence of twins compared to the shear modulus. The numerical results are consistent with a two-scale homogenization estimate that utilizes laminate materials to model the interactions of twins.
AB - A stochastic 3D microstructure model for polycrystals is introduced which incorporates two types of twin grains, namely neighboring and inclusion twins. They mimic the presence of crystal twins in γ-TiAl polycrystalline microstructures as observed by 3D imaging techniques. The polycrystal grain morphology is modeled by means of Voronoi and –more generally– Laguerre tessellations. The crystallographic orientation of each grain is either sampled uniformly on the space of orientations or chosen to be in a twinning relation with another grain. The model is used to quantitatively study relationships between morphology and mechanical properties of polycrystalline materials. For this purpose, full-field Fourier-based computations are performed to investigate the combined effect of grain morphology and twinning on the overall elastic response. For γ-TiAl polycrystallines, the presence of twins is associated with a softer response compared to polycrystalline aggregates without twins. However, when comparing the influence on the elastic response, a statistically different polycrystalline morphology has a much smaller effect than the presence of twin grains. Notably, the bulk modulus is almost insensitive to the grain morphology and exhibits much less sensitivity to the presence of twins compared to the shear modulus. The numerical results are consistent with a two-scale homogenization estimate that utilizes laminate materials to model the interactions of twins.
KW - Crystallographic twin
KW - Elastic response
KW - Electron back-scattered diffraction
KW - Fast Fourier transform
KW - Full-field computation
KW - Homogenization
KW - Polycrystalline material
KW - Stochastic 3D modeling
KW - Tessellation
KW - Twinning
UR - http://www.scopus.com/inward/record.url?scp=85187203364&partnerID=8YFLogxK
U2 - 10.1016/j.commatsci.2024.112922
DO - 10.1016/j.commatsci.2024.112922
M3 - Article
SN - 0927-0256
VL - 238
JO - Computational Materials Science
JF - Computational Materials Science
M1 - 112922
ER -