Heat Diffusion in Polycrystalline Rolled Steel - A Microstructure Based Material Model

Abstract

A two-dimensional Voronoi tessellation based material model has been introduced to study the heat diffusion phenomena in polycrystalline materials consisting of a distribution of grain sizes and shapes. A method to control Voronoi cell-size distributions is presented. As the main focus of the numerical investigation is to study the role of anisotropy of the thermal conductivities in each grain of the polycrystalline material, the thermal conductivity tensor of each cell is chosen to correspond to a random crystallographic orientation. A finite element analysis of heat transport from a centrally spot-heated sample is carried out on the Voronoi tessellated domain for a fixed cell size distribution and a set of randomly oriented cells. The simulations are carried out for various sets of cell orientations. Time-Temperature profiles are generated at two orthogonally placed probes for each trial. Three inter-cell boundary conditions are examined to account for the heat transport across grains. The observed trends of the time-temperature profiles in the context of effective thermal conductivity of a polycrystalline material are discussed.

Data-driven simulation-assisted-Physics learned AI (DPAI) for heat diffusion in large grain polycrystalline materials

“…The ratio of K 1 and K 2 is chosen such that it is higher than most of the metals [1,[27][28][29][30]. Ths higher ratio of K 1 and K 2 enables the model to learn the most extreme shape of isotherms and hence the DPAI model can predict the heat diffusion for most of the metals.…”

“…The anisotropic nature of materials at the microscopic level significantly impacts their macroscopic properties. Studying the microstructure helps in understanding the thermal properties of materials, such as thermal conductivity, diffusivity, and emissivity, at the macroscopic level [1]. Many engineering materials are polycrystalline and consist of discrete crystals called grains, which are separated by grain boundaries.…”

“…Previous works have shown that the effective properties of the material microstructure are calculated using statistical methods known as material homogenization. In the last few decades, some researchers have been interested in studying the homogenized thermal properties of the microstructure [1]. However, limited research has reported on the exact diffusion of heat into the microstructure.…”

“…Moreover, those works have studied thermal diffusion in the microstructure using traditional numerical methods. The study is also limited to a particular material rather than any general case [1,5,6].…”