TITLE:
Study of Oxidation Kinetics in Air of Zircaloy-4 by in Situ X-Ray Diffraction
AUTHORS:
Noureddine Selmi, Ali Sari
KEYWORDS:
Zircaloy-4; High Temperature Oxidation; Zirconium Oxides; In Situ X-Ray Diffraction
JOURNAL NAME:
Advances in Materials Physics and Chemistry,
Vol.3 No.2,
June
19,
2013
ABSTRACT: The zircaloy-4 is an alloy
of zirconium, which has a very weak thermal neutron absorption, satisfactory mechanical
properties and good corrosion resistance at high temperature. For these reasons,
zircaloy-4 is used as a material of cladding fuel rod of nuclear reactors. In
this environment, it is submitted to different severe conditions of temperature
and pressure. The objective of this work is to study the oxidation kinetics of zircaloy-4 in air by the
X-ray diffraction technique. The experiments were realized in a “HTK1200” furnace installed as
a sample holder in the diffractometer at different temperatures; 25°C, 350°C, 500°C, 830°C and 1000°C. The results show that the monoclinic and the tetragonal
phases are formed at 350°C temperature. The volume fraction of these phases increased with the temperature
until 1000°C where the α phase disappears
completely. For simulating the case of loss-of-coolant-accident (LOCA),
we have done x-ray diffraction
of Zry-4 samples water quenched at 1050°C with different ageing times at this temperature. At 10
seconds and more, there is an important evolution of monoclinic and tetragonal zirconias, which leads to the degradation of zircaloy-4 properties.