Meaning
Electron backscatter diffraction analytical metrics compute the average crystallographic orientation difference between a central measurement point and its nearest neighboring points. In microstructural characterization, kernel average misorientation quantifies localized lattice distortion, dislocation density, and geometrically necessary dislocations in crystalline materials. Mapping misorientation reveals local residual strain distributions within metallic microstructures.
Lattice Curvature
Orientation differences within a local pixel neighborhood indicate underlying crystal lattice bending caused by mechanical working. Calculating kernel average misorientation involves averaging misorientation angles while filtering out high-angle grain boundaries. Step size selection during diffraction mapping directly influences the calculated scalar value.
Strain Mapping
Color-coded orientation maps visually highlight areas of high strain concentration along grain boundaries and phase interfaces. Utilizing kernel average misorientation allows materials scientists to differentiate fully recrystallized grains from heavily cold-worked material zones. Quantitative strain mapping supports failure analysis in deformed metal components.
Plastic Deformation
Localized dislocation accumulation increases as metals undergo cold forming, stamping, or fatigue loading operations. When analytical software processes electron backscatter data, kernel average misorientation serves as an indirect measurement of local plastic deformation history inside the alloy matrix. Structural alloy developers rely on misorientation metrics to evaluate stress relief annealing efficiency.
Precision components with elevated local misorientation levels exhibit reduced resistance to stress corrosion cracking.
