A high temperature X-ray diffraction study of the crystallisation of amorphous ball-milled zircon

Corrosion kinetics and mechanisms of ZrC1−x ceramics in high temperature water vapor

The corrosion kinetics and mechanisms of ZrC_1−x ceramics in water vapor between 800 and 1200 °C were investigated. The results showed that there was only cubic ZrO₂ phase in the corrosion layer when corroded at 800 °C, while a scale layer consisted of a mixture of cubic and monoclinic ZrO₂ phases when corroded at 1000 °C and 1200 °C. A series of crystallographic relationships at the ZrC/c-ZrO₂ interface were detected. The c-ZrO₂ formed near the interface retained some crystallographic orientations of the initial ZrC before corrosion, presenting an “inheritance in microstructure” between c-ZrO₂ and ZrC. The corrosion behavior mainly followed a parabolic relationship. The incremental rate of weight gain increased with increased corrosion temperature and decreased C/Zr ratio and the carbon vacancy was passive to the decrease of corrosion rate. The main corrosion controlling mechanism changed from phase boundary reactions to surface diffusion and then to grain boundary diffusion with increased temperature.

Studies on the corrosion kinetics and mechanisms of ZrC_1−x ceramics in water vapor are reported for the first time.

Connecting defects and amorphization in UiO-66 and MIL-140 metal–organic frameworks: a combined experimental and computational study

Ball-milling amorphization of UiO-66, MIL-140B and MIL-140C was observed to proceed by metal–ligand bond breaking, and linked to the generation of successive defects.