Enhanced mechanical properties of aluminum nitride-yttria ceramics through grain refinement by pressure assisted two-step sintering

Aluminum nitride (AlN) has gained significant attention as a promising ceramic substrate for electronic devices due to their extremely high thermal conductivity and superior electrical resistivity. However, their application is often limited by poor mechanical properties. Here, we employed pressure-assisted two-step sintering to prepare AlN-Y2O3 ceramics, aiming to enhance mechanical performance through grain refinement. Pressure-assisted high-temperature heating at 1680 degrees C followed by microstructural freezing at lower temperatures led to a significant reduction in grain size from 2.21 mu m to 1.08 mu m, resulting in improved flexural strength, Vickers hardness, and fracture toughness. Particularly, T2 of 1650 degrees C has produced a well-balanced performance of mechanical and thermal properties exhibiting a flexural strength of 417 MPa and a thermal conductivity of 144 W/m center dot K. These findings provide valuable insights into the development of advanced AlN-Y2O3 ceramics for electronic device applications, while maintaining the composition free from additional reinforcement additives.

Automated summary

Aluminum nitride (AlN) ceramic substrates show promise for electronic devices due to their high thermal conductivity and electrical resistivity. However, their application is limited by poor mechanical properties. In this study, pressure-assisted two-step sintering was used to prepare AlN-Y2O3 ceramics with refined grains, resulting in improved mechanical performance. Understanding the development of advanced AlN-Y2O3 ceramics for electronic devices without additional reinforcement additives is important to enhance their application potential.