The effects of nanoparticle addition on the sintering and properties of bimodal AlN

The effects of nanoparticle addition on the pressureless sintering of injection molded and debound aluminum nitride (AlN) samples were studied. Variations in the densification, microstructure, and properties owing to the increased powder content and reduced particle size are discussed. The results indicate the formation of liquid phase at 1500 °C in the bimodal micro (μ)–nano (n) AlN samples, a temperature that is at least 100 °C lower than typically reported values in the literature. Consequently, a densification ≥ 99% was achieved by pressureless sintering at a relatively lower temperature of 1650 °C with ∼14% isometric shrinkage. Additionally, thermal and mechanical properties of the sintered bimodal AlN samples are presented and compared with sintering studies on conventional monomodal μ-AlN systems reported in the literature.