Mechanical properties and thermal shock resistance performance of spark plasma sintered MgO–Al2O3–SiO2 ceramics

Abstract

MgO–Al2O3–SiO2 composite ceramics were prepared by spark plasma sintering (SPS). In addition, phase composition, microstructure, mechanical properties, and thermal shock properties have been systematically characterized. Introduction of Al2O3 and SiO2 significantly increased mechanical properties and thermal shock resistance of these composite ceramics. MgO–Al2O3–SiO2 composite ceramics prepared by spark plasma sintering (SPS) exhibited fine grain size. Reduced grain size may result in extraordinary properties. Experimental results showed that MgO–Al2O3–SiO2 composite ceramics had the highest flexural strength and hardness among all studied ceramics of 269.6 ± 9.22 MPa and 12.51 ± 0.29 GPa, respectively. Moreover, MgO–Al2O3–SiO2 composites can reach 16 thermal cycle times. This shows that it is feasible to prepare high-performance MgO composite ceramics by SPS. Furthermore, introduction of Al2O3 and SiO2 is effective method to improve mechanical properties and thermal shock resistance of MgO composite ceramics.