Thermal-Elastic Response of Polycrystalline Microstructures: Influence of Grain Orientation Configuration
Lin-Sien H. Lum, D M. Saylor, T Weiss
Two-dimensional, microstructure-based finite element simulations were used to elucidate the influence of grain orientation configuration on the thermal-elastic response of polycrystalline ceramic materials. Two minerals found predominately in marbles, calcite and dolomite, and alumina were studied. The crystallographic configuration of the grains described in terms of the distribution of grain orientations and grain-boundary misorientations present in the microstructure. To probe the influence of grain orientation configuration, we first generated the geometry of a hypothetical microstructure. Next, crystallographic orientations were assigned to each grain in the microstructure such that the grain orientations and grain boundary misorientations matched predefined distributions. By varying the predefined distributions, we generated 45 unique microstructures covering a wide of crystallographic configurations. After assigning thermal-elastic properties to each structure corresponding to calcite, dolomite, and alumina, finite element calculations were performed. The calculations demonstrated that both the orientation and misorientation distributions can have a substantial impact on the thermal-elastic response. We find that for microstructures with the same material properties, varying the crystallographic configuration can result in variations of elastic strain energy density up to 29 kJ/m3.