From the Oxidation Behavior of Ceramic Materials at High Temperature Up to the Self-Healing of Ceramic Matrix Composite

The resistance to oxidation of ceramic materials is a key property for many applications as the aeronautical domain, aerospace sector, the nuclear field, energy storage or production, refractory industry, …. Indeed, they must withstand temperatures of up to 2000 °C in environments ranging from ambient air to high vacuum and high pressures (under high pressures or on the contrary, in a rarefied atmosphere with oxidizing and/or corrosive species). For this reason, it is important to predict the consequences of an oxidizing treatment on these materials and their mechanical properties. These phenomena can reduce the lifetime in considerable proportions. The description of oxidation behavior of many ceramics is gathered. Some classic methods to better describe these latter are mentioned. Further, in a ceramic matrix composite, embrittlement is possible by the introduction of a new mode of cracking with regard to monolithic ceramic. At high temperatures, these cracks developed in the matrix become pathways for the circulation of oxygen to sensitive points in the material, particularly the fiber/matrix interphases (thin layer of a low-rigidity material, often made of carbon). This phenomenon is slowed down at high temperatures if the oxidation of the matrix leads to the formation along the walls of cracks an oxide layer thick enough to locally close the cracks and stop the access to oxidizing gaseous species.