Papers by Keyword: Al₂O₃/SiC

Abstract: In this study, silica obtained from the rice husk was used to synthesis of Al₂O₃/SiC nanoparticles. For this reason, the ash obtained from the burning of the rice husk which contains more than 93 wt. % silica, aluminum and carbon powders with the molar ratios of 3:4:6 were mixed and then compacted into pellets by using a cylindrical die under a pressure 50MPa. In order to conduct the self-propagating high-temperature synthesis (SHS), the produced pellets were placed in an electrical furnace at 850°C under the argon gas atmosphere. Then, a planetary ball milling for 4 to 24h was used to decrease the particle size of the synthesized composite. The results of XRF, XRD, SEM and DLS investigations shown that the rice husk ash can be used to fabricate Al₂O₃/SiC nanoparticles with an average particle size of about 80 to 65nm via SHS process and ball-milling for 12 to 24h.

Abstract: Densification behavior, microstructural developments and mechanical properties of 5 wt% SiC nano particulate toughened Al2O3 composites were prepared by using microwave sintering at different sintering temperatures. Densities of up to 97.5% of the theoretical value were achieved at temperature as low as 1380°C. Improvements in fracture toughness and bending strengths are of the order of 99% theoretical dense conventionally sintered composites. Surface heating was observed at the final stages of densification. No thermal runaway was observed in the nanocomposites due to presence of SiC spheroids.