Thermo‐elastic Homogenization of 3‐D Steel Microstructure Simulated by the Phase‐field Method

Abstract

A multi-scale approach based on the asymptotic homogenization method of periodic material structures is applied here to determine the effective thermo-elastic properties of 3D steel microstructures, which have been calculated by phase-field simulations. A multiphase-field model, coupled to thermodynamic databases, is used to evaluate the microstructure evolution during the austenite to ferrite phase transformation of low carbon Fe-C-Mn steel. In order to derive effective mechanical properties, geometrical information about the grains, their phase properties and crystallographic orientations are transferred to the homogenization tool. Effective cubic Young and shear modules and Poisson coefficients are predicted for different ferrite volume fractions. Moreover, the volume change is derived as function of the phase fractions, leading to a calculated dilatometer curve. The effects of the thermal shrinkage and the volume expansion caused by the phase transformation are taken into account.

An ICME Process Chain for Diffusion Brazing of Alloy 247

“…Following a description of the experimental setup, the different materials, and the phases constituting these materials, the process chain is detailed step by step: Simulation of casting/solidification is followed by a solution heat treatment process and by the simulation of brazing, which in turn provides the phase distributions and segregation patterns for a sub-μ scale modeling of the microstructure development during annealing and service. Finally, the rafting process occurring under mechanical load during service is quantified as a change in the effective properties of the material using the HOMAT software tool [29]. Compositions of all materials (different base materials and different solder foils) are summarized in Table 1.…”

“…19 (right). To quantify the microstructural changes as well as for quantitative comparisons to experimental data, the simulated microstructures were conveyed to the homogenization tool HOMAT [29]. HOMAT calculates effective anisotropic properties of a material based on the properties of the pure phases and their arrangement in the microstructure.…”

“…HOMAT is typically used for calculation of effective mechanical properties by linear homogenization [29]. In the present application, the high sensitivity of this tool allowed for indirectly analyzing the progress of rafting by calculating the anisotropy of isothermal expansion based on the phase-field simulation results (Fig.…”

Phase-field based simulation of microstructure evolution in technical alloy grades

“…Nowadays it can be also used to derive effective mechanical engineering constants, e.g. the Young's modulus from simulated, complex multiphase microstructures [61]. Effects of inelastic deformations on solid state transformations have been investigated in [62].…”

Towards integrative computational materials engineering of steel components

“…The mathematical homogenization tool HoMat [17] at first evaluates the effective thermoelastic properties of the pearlite bilamella formed by a ferrite and cementite layer. As pearlite exhibits a large stiffness, this phase is assumed to have a pure elastic material behaviour.…”