Microstructural studies on lattice imperfections in deformed zirconium-base alloys by X-ray diffraction

X-ray diffraction intensity data from three compositions of zirconium-base alloys, viz. ZIRCALOY-2, ZIRLO, and Zr-25 pet Nb, having extensive applicat ion in nuclear industry were recorded using a PHILIPS PW 1730 X-ray diffrac tometer. Detailed studies using the recorded diffractometer data, keeping i n view the recent trends in the powder diffraction analysis, were carried o ut with a view to evaluating the microstructural paramaters, including doma in size, microstrain, faulting probability, and dislocation density. While faulting appears to be absent in all alloys, the average domain size and ro ot-mean-square (rms) strain appear to be smaller compared to pure zirconium . However, both of these parameters, i.e., average domain size and rms stra in tend to increase with the addition of Nb, as in ZIRLO, but display a dim inishing trend with higher content of Nb, as is evident in the Zr 2.5 pet N b alloy.