# Warren-Averbach line broadening analysis from a time of flight neutron diffractometer

## TL;DR

This paper demonstrates that Warren-Averbach line broadening analysis can be effectively applied to time of flight neutron diffraction data, enabling non-destructive microstructural characterization of materials.

## Contribution

The study extends Warren-Averbach theory to time of flight neutron data without modification, validated on steel and ceramic composites for dislocation and strain analysis.

## Key findings

- Root mean square strains in steel agree with EBSD measurements.
- Dislocation densities estimated from neutron data match independent measurements.
- Analytical model supports strain estimates in ceramic composite.

## Abstract

The well known Warren-Averbach theory of diffraction line profile broadening is shown to be applicable to time of flight data obtained from a neutron spallation source. Without modification, the method is applied to two very different examples; a cold worked ferritic steel and a thermally stressed alumina-30% SiC composite. Values of root mean square strains averaged over a range of lengths for the ferritic steel were used to estimate dislocation densities; values were found to be in good agreement with geometrically necessary dislocation densities independently measured from similarly orientated grains measured from electron backscatter diffraction analysis. An analytical model for the ceramic is described to validate the estimate of root mean square strain.