Enhancing the hardness of alumina-zirconia-CNT composites using alumina-graphite powder bath to provide homogeneous sintering

ABSTRACT Using a conventional sintering (CS) process, it is difficult to eliminate pore distribution across ceramic composites, resulting in mechanical properties destruction. In this study, 90%–95% of pores were reduced with the same sintering parameters by replacing CS with the cutting-edge Alumina-Graphite Powder Bath (AGPB) sintering method. Alumina-Zirconia-CNT(AZC) composites were fabricated using both AGPB and CS methods. The ceramic samples were surrounded by alumina-graphite powder particles in the AGPB method, which provided indirect homogeneous heating to the samples. This powder bath setup changed convection-radiation heat to conduction heat and produced sintered product with pore-free microstructures. The hardness of the AGPB-AZC composite was 43% higher than the CS-AZC, demonstrating the exponential property enhancement caused by cutting-edge AGPB sintering. The AGPB-AZC FESEM investigation revealed the formation of a homogenous microstructure with minimum pores, which eventually increased the hardness.