X-ray line profile analysis was an efficient non-destructive technique to determine some key statistical properties of dislocation structures developing during plastic deformation. In the first part of the paper recent developments describing the asymptotic behavior of the line profiles were outlined. A new evaluation method was presented to determine the average dislocation density and its spatial variation. The method was demonstrated on measurements obtained on compressed Cu single crystals. After this, it was shown that the relative dislocation density fluctuation exhibits a sharp maximum at the stages II–III transition. A nano-indentation tests indicate that the fluctuations of other quantities behave similarly. The results give new insight into the dislocation phenomena taking place in the stage III deformation regime.

Evolution of the Statistical Properties of Dislocation Ensembles. I.Groma, A.Borbély, F.Székely, K.Máthis: Materials Science and Engineering A, 2005, 400-401, 206-9