Relationship between dislocation multiplication and work hardening of tensile-deformed Cu-Zn alloys with different grain sizes was in-vestigated.
X-ray diffraction line-prole analysis was employed to evaluate dislocation parameters. It was conrmed that dislocation multi-plication was enhanced
with a decrease in the grain sizes. This was mainly caused by GN ÿGeometrically Necessaryÿ dislocation, which was characterized by KAM ÿKernel
Average Misorientationÿ in EBSD ÿElectron Back Scatter Diffractionÿ. The strength of dislocation hardening was evaluated from the ÿ value in the
Bailey-Hirsch equation: ÿ = ÿ0 + MTÿGb ÿÿ. The ÿ values were estimated by plotting the ow stress against square root of dislocation density. The ÿ
values became smaller with the decrease in the grain sizes, suggesting that the strength of dislocations hardening for unit length of dislocation
became smaller. In order to elucidate the origin of the relationship between the grain size and the ÿ values, the inuence of grain size on the fraction
of GN dislocation density as well as the outer radius of dislocation strain eld.