POWDER INJECTION MOLDING OF BIMODAL μ-n SILICON CARBIDE AND ALUMINUM NITRIDE CERAMICS

摘要

Effect of employing a bimodal micro-nano (μ-n) mixture towards the green density and sintering of injectionmolded SiC and AlN is studied. Nanoparticle additions were found to increase the critical solids loading to65 and 71 vol.% for SiC and AlN systems, respectively. The extruded feedstocks with an optimal solidsloading formulation were characterized to short-list the injection molding temperatures. The nanoparticlesaddition even though found to catalyze the thermal degradation of binders, slowed down the overalldebinding of the injection molded “green” samples. The nanoparticles were found to improve thesinterability of AlN and SiC by reducing the liquid phase formation to 1500 and 1800 °C, respectively.Around 99.3% density is obtained for bimodal μ-n AlN system when pressureless sintered at 1650 °C.Similarly, 97% density is obtained for bimodal SiC system when sintered at 1950 °C.