Mechanical and dielectric properties of MgO ceramics with HNT additions

This study, the ceramics’ sintering, mechanical, and dielectric properties were examined, and the influence of HNT additives on these properties was investigated. HNT was added to the structure as a SiO₂ source to the MgO ceramics, which are difficult to process, since SiO₂ suppresses the grain growth of MgO ceramics and significantly reduces the sintering temperature. After calcination at 800 °C HNT at different ratios (1, 3, 5, 7, 9, 11 wt%) were added to calcined MgO powder. As a result of XRD analysis, it was determined that spinel, forsterite and periclase phases were formed and these results were also confirmed by SEM images. The addition of HNT led to the formation of the forsterite phase at grain boundaries, enhancing mechanical properties. The best mechanical properties were observed in MgO ceramics with 11% HNT additives. Adding HNT at different ratios increased the dielectric constant of MgO ceramics. HNT-added MgO ceramics exhibited higher dielectric constant value than those at ambient temperature. The lowest dielectric constant value was measured as ~ 8.5 for MgO ceramic without any HNT addition. Since the materials to be used as circuit substrates require strict dielectric and mechanical properties, it is aimed to improve the mechanical and dielectric properties of MgO ceramics with the addition of HNT. MgO ceramics incorporating HNT in this study exhibited outstanding dielectric and mechanical characteristics, suggesting their potential as favorable materials for circuit substrates.