Dear Simson Daniel,

Dislocation density can be found out by knowing the grain size, lattice strain and Burger's vector of the material (eg: BV of Al is 0.286 nm)

Lattice strain can be obtained by using XRD peak broadening as-per the Williamson-Hall method.

You may find a reference in Ma et al. "Mechanical behavior and strengthening mechanisms in ultrafine grain precipitation-strengthened aluminum alloy"

Regards

Anas

These are some similar discussions, you can take some help from there,

https://www.researchgate.net/post/How_can_i_calculate_dislocations_density_from_the_XRD_patterns2

https://www.researchgate.net/post/How_to_determine_the_dislocation_density_by_XRD_and_subsequent_analysis

https://www.researchgate.net/post/What_is_the_best_method_to_measure_dislocation_density

thank you Anas & Yadav. really your answer help me lot.