Sea snail shells for synthesis of ceramic compounds reinforced with metallic oxide: Microstructural, mechanical and electrical behavior

The focus of this study is to investigate the effect of Cu₂O formation in the CaO·Al₂O₃ ceramic compounds synthesized by a powder processing method. For the synthesis, chemical compositions were prepared between CaCO₃ powder from sea snail shells, Al₂O₃ powder, and separate additions of Cu powder at 0.0%, 0.5%, 1.0%, 1.5%, and 3.0% by weight. The chemical compositions were subjected to a mix-milling process, then compacted in cylindrical samples and sintered at 1500ºC for their consolidation in a nitrogen-air atmosphere. The synthesized materials were analyzed by X-ray diffraction and scanning electron microscopy. In addition, the mechanical and electrical properties were evaluated. In the results, the X-ray analysis identified the formation of the CaAl₂O₄, Ca₁₂Al₁₄O₃₃, and Cu₂O phases. The presence of Cu₂O in materials causes changes in hardness, fracture toughness, capacitance, and dielectric constant. For example, the material compounds with Cu₂O reach a hardness of up to 12.8 GPa, while material without Cu₂O reaches a hardness of 7.8 GPa. Likewise, the capacitance is between 11.1 pF and 10.1 pF, respectively. The materials obtained possibly can be used in dental applications, materials with antimicrobial activity, or applied in telecommunication as radiofrequency oscillators, due to their electrical properties.