Study of Microwave Heating Effect in the Behaviour of Graphene as Second Phase in Ceramic Composites

• Main Authors: Rut Benavente, María Dolores Salvador, Alba Centeno, Beatriz Alonso, Amaia Zurutuza, Amparo Borrell
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Materials
• Subjects: <i>β</i>-eucryptite; graphene; microwave sintering; mechanical properties; microstructure
• Online Access: https://www.mdpi.com/1996-1944/13/5/1119

The choice of the right material is essential in microwave processing. The carbon materials are good microwave absorbers, which allows them to be transformed by microwave heating into new carbon materials with adapted properties, capable of heating other materials indirectly. In this paper, the microwave heating of graphene as reinforcement of the lithium aluminosilicate (LAS) ceramics has been explored. LAS ceramics have a near-zero coefficient of thermal expansion and exhibit an effective and efficient heating by microwave. Nevertheless, we have found that the graphene did not show any significant response to the microwave radiation and, hence, the interaction as mechanical reinforcement with the LAS material is harmful. The possible benefits of graphene materials to microwave technology are widely known; however, the mechanism involved in the interaction of microwave radiation with ceramic-graphene composites with high dielectric loss factors has not been addressed earlier.