Accessing the grain boundary network evolution, proof of principle, and application to high T and high P deformation.
MARQUARDT K. 1
1 Imperial College London, London, United Kingdom
The microstructure of modern materials evolves to adapt to changing external conditions and is critical to understand the material's structural stability and performance. While single crystal properties are exceedingly well understood and some microstructural characteristics begin to impact our understanding, the grain boundary character and population evolution are poorly understood – despite ever-growing evidence of their importance for material performance. The expression of grain boundaries in their 5 macroscopic degrees of freedom and their capability to existing in multiple stable/metastable structures requires high-quality 3D understanding usually obtained from 3D characterization. To date, 3D characterization is critical for the analysis of the grain boundary network in textured samples.
We propose how the grain boundary network can be studied on textured samples using 2D analysis of 3 perpendicular sections. To establish a proof of principle, we characterize simulated microstructures as if they were a set of EBSD maps. We use these to evaluate the quality of results obtainable from our analysis technique if applied to textured samples. Our case study is performed on a textured poly-crystalline sample synthetically generated using Dream3D. The simulated microstructure serves as the ground truth and is subsequently analyzed on 3 orthogonal sides as if using electron backscatter diffraction (EBSD) orientation mapping. We observe that combining grain morphology information from 3 orthogonal sides provides the expected averaged 3D GBPD for textured samples.
We will present a grain boundary character distribution study evaluating the evolution of grain boundary populations during dislocation-assisted grain boundary sliding (disGBS) during experimental deformation. Our results suggest that the rate of deformation is controlled by the assimilation of dislocations into grain boundaries and controls the specific type of grain boundaries formed.