Zirconium Carbide Oxidation: Maltese Cross Formation and Interface Characterization

Claudia Gasparrini (1) , Renaud Podor (2) , Denis Horlait (3, 1) , Richard Chater (4) , William Edward Lee (1)

1 Department of Earth Science and Engineering [Imperial College London]
2 L2ME - Etude de la Matière en Mode Environnemental
3 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
4 Department of Materials

Oxidation of dense hot-pressed ZrC specimens from 1073 to 1473 K was investigated using an in situ technique: HT-ESEM. Cuboid specimens were monitored on the surface and on edges and corners during oxidation in order to understand the influence of crack formation and propagation on the Maltese cross shape development of the oxide. The oxidation mechanism comprised three steps: (1) delamination of sample edges, (2) crack formation at corners and (3) crack propagation towards the inner core and formation of microcracks parallel to the interface that increase the accessible surface area followed by a drastic volume expansion. The microcrack pattern is found to be repetitive as if a cyclic debonding of the interface occurred. Characterization of the interface by TEM and HRTEM revealed

Domaines: Matériaux

Claudia Gasparrini, Renaud Podor, Denis Horlait, Richard Chater, William Edward Lee. Zirconium Carbide Oxidation: Maltese Cross Formation and Interface Characterization. Oxidation of Metals, 2017, 88 (3-4), pp.509-519. ⟨10.1007/s11085-016-9672-6⟩. ⟨hal-01998470⟩