Low-Temperature Degradation of Composite ATZ Ceramics Reinforced via Multiwalled Carbon Nanotubes

Resumo

The influence of water vapor on structural stability and mechanical properties of ceramics based on baddeleite (natural zirconia mineral) and chemically deposited ZrO₂ reinforced with carbon nanotubes is studied in this work. These composites are shown to possess high physical and mechanical properties and elevated hydrothermal aging resistance. Composites based on baddeleite and stabilized СаО are characterized via ageing rate of an order of magnitude lower than in the case of commercial ceramics stabilized with Y₂О₃. The embedding of carbon nanotubes in the composites and the use of spark plasma sintering inhibits the grain growth and amplifies the scale effect in hardness. With that, crack resistance K_C under hydrothermal conditions decreases to a lesser extent than in nanotube-free composites.