Resolving geometrically necessary dislocation density onto individual dislocation types using EBSD-based continuum dislocation microscopy

Modeling of plasticity is often hampered by the difficulty in accurately characterizing dislocation density on the microscale for real samples. It is particularly difficult to resolve measured dislocation content onto individual dislocation types at the length scales most commonly of interest in plasticity studies. Methods have been developed to analyze dislocation content at the continuum level using the Nye tensor and Kröner's fundamental relation of continuum dislocation theory to interpret the local strain gradients obtained from high resolution electron backscatter diffraction (HREBSD). This paper assesses an implementation of the Nye-Kröner-Bilby method for resolving measured geometrically necessary dislocation content onto individual dislocation types via a novel simulation of distortion fields around continuum fields of dislocation density based on classical continuum elasticity equations. It is then applied to HREBSD data for a micro-indented nickel single crystal.