Structure and composition of zirconium oxide films formed in high pressurewater with different Li+ concentration at 360 degrees C

The structure and composition of surface layers formed on different Zr-allo ys during corrosion in high pressure water with different Li+ content at 36 0 degrees C were investigated by X-ray diffraction, Raman spectroscopy and metallography. X-ray diffraction of surface layers clearly demonstrated the existence of the monoclinic form of ZrO2 which showed the strong preferred orientation (0 0 2) and significant broadening of reflections due to micro strain in layers or small crystallite size, The existence of tetragonal for m could not be undoubtedly proved by X-ray diffraction and had to be verifi ed using Raman spectroscopy. The coating thickness was determined by metall ography, weight gain due to metal/oxide transformation and absorption of X- ray radiation. The results obtained gave acceptable agreement for layer thi ckness determined by weight gain and metallography while those from X-ray d iffraction show 10-20% deviation. (C) 2000 Elsevier Science S.A. All rights reserved.