Incorporation of TERGO and EG in Plasma Sprayed Ceramics Coatings for Improved Microwave Absorption and Tribological Properties

The coating that combines efficient microwave absorption performance and excellent tribological properties has important research value. Herein, firstly, the ceramic precursor was coated on expanded graphite (EG) or thermally expanded reduced graphene oxide (TERGO) sheets to prevent aggregation. Then, the treated EG and TERGO were homogeneously dispersed in the ceramic matrix to prepare two types of graphene-based/ceramic coatings by plasma spraying. The microwave absorption properties and tribological properties with different load of all coatings have been systematically investigated. Remarkably, the microwave absorption properties of the TERGO/Al₂O₃ coating achieve wide bandwidth (reflection loss ≤ − 10 dB coved 2.8 GHz), and strong absorption (reflection loss of −35.3 dB) as the thickness of 2.1 mm. Meanwhile, the TERGO/Al₂O₃ coating possesses excellent tribological properties, and the coefficient of friction and wear rate were decreased by 41 and 90% respectively compared with pure Al₂O₃ coating. This study paves the way for preparing microwave absorbing coating with tribological properties.