Second-Phase Grain Boundary Engineering in Al2O3-MgAl2O4 Composites: Microstructure and Dielectric Breakdown Reliability
Highlights A dual-pathway mechanism governs in situ MgAl2O4 spinel formation in alumina matrix. The optimal kaolin/MgO ratio of 4:1 yields a 17.74 kV/mm characteristic breakdown strength. Excess MgO incorporates into glassy phase, inducing ionic conduction channels. A microstructure–defect–breakdown correlation model i...