Papers by Keyword: Ceramic Synthesis

Abstract: This research synthesized a composite ceramic material base CaCO₃/Al₂O₃, CERMET, with possible biomedical applications. Eggshell was used as raw material to obtain CaCO_3, and it was reinforced with silver nanoparticles to improve the structural and mechanical properties of the ceramic system. The addition of silver nanoparticles promotes the formation of two phases. The first is a continuous phase called a matrix formed of CaAl₂O₄ (calcium aluminate). The second is a dispersed phase known as reinforcement made up of silver nanoparticles. The composite ceramics were synthesized using the solid-state synthesis technique from a chemical mixture of CaCO₃ and Al₂O₃ powders in the following chemical ratio: 49.5% CaCO₃ + 50.5% Al₂O₃, with silver nanoparticles added at different percentages (1%, 5%, 10%, 15%). The powder mixture was made in a high-energy mill for homogenization. After that, the mixture was compressed into cylindrical samples for their consolidation by sintering in a high-temperature muffle with a controlled atmosphere, using heating ramps. The sintered samples were characterized by X-ray diffraction, optical microscopy, scanning electron microscopy, and microhardness, including fracture toughness studies. In addition, the Archimedes method determined the sintered samples' density. The results showed a clear relation between the mechanical properties of the CaAl₂O₄ ceramic base and the incorporated silver nanoparticles since these increased as the percentage of silver nanoparticles increased. In addition, it was observed that the porosity of the samples could be controlled, making the composite material suitable for biomedical applications.

Abstract: In the present study, a method based on sulfuric acid dehydration of sugar was developed to synthesis a precursor material, which can yield B4C/ TiB2 composites at much lower temperatures compared to traditional carbothermal methods. The precursor material for pure B4C and B4C / TiB2 composites were heat treated at 1650oC under Ar and Ar+H2 atmosphere. Then the samples were characterized by X-ray diffraction (XRD) and crystallized B4C and B4C / TiB2 composites can be obtained at 1650oC

Abstract: In the present study, a method based on sulfuric acid dehydration of sugar was developed to synthesize a precursor material, which can yield B4C/SiC composites at much lower temperatures compared to traditional carbothermal methods. The precursor material for pure B4C was heat treated at the temperatures between 400 and 1600oC under inert atmosphere. The precursor material for B4C /SiC composites was heat treated only at 1600oC under an inert atmosphere. Then the samples were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that B-C bonds formed as low as 400oC. On the other hand, crystallized B4C and B4C / SiC composites can be obtained at the heat treatment temperatures between 1400 and 1600oC.