Synthesis, hydration and sintering of calcium aluminate nanopowder for advanced applications

• Published in: Comptes rendus. Chimie Vol. 14; no. 6; pp. 611 - 618
• Main Authors: Zawrah, Mahmoud F., Shehata, Adel B., Kishar, Esam A., Yamani, Randa N.
• Format: Journal Article
• Language: English
• Published: Paris Elsevier SAS 01.06.2011; Elsevier
• Subjects: Calcium aluminate; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Hydration; Nanopowder; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Powders; Sintering; Synthesis; Synthesis; Calcium aluminate; Nanopowder; Hydration; Sintering; Ternary compound; Aluminium oxide; Binary compound; Calcium oxide; Nanoparticle; Powder; Aluminium Oxides; Calcium Oxides
• ISSN: 1631-0748; 1878-1543
• DOI: 10.1016/j.crci.2010.11.004

Seven batches of calcium aluminate powder containing different ratios of alumina and calcium oxide were chemically prepared by thermal decomposition method. The produced powder was investigated in terms of phase composition and morphology by XRD pattern and scanning electron microscope (SEM). The hydration and sintering of the prepared powder were also studied. Phase composition, microstructure and mechanical properties of the hydrated and sintered bodies were tested. The results revealed that the batches containing high CaO/Al 2O 3 ratios i.e., batches 1, 2 and 3 composed mainly of CaO.Al 2O 3 (CA) and 12CaO.7Al 2O 3 (C 12A 7) phases while batches containing low CaO/Al 2O 3 ratios i.e., batches 4, 5, 6 and 7 composed of CA and CA 2 (CaO.2Al 2O 3) phases. The amount of these phases affected the properties of hydrated as well as the sintered bodies. The hydration of batches No. 1, 2 and 3 achieved higher strength than batches containing low CaO/Al 2O 3 ratios due to the presence of CA and C 12A 7 as a major component, since they react rapidly with water. The presence of C 12A 7 phase in the batches containing higher CaO/Al 2O 3 ratios decreased the apparent porosity and consequently increased the mechanical properties of the sintered bodies. The obtained materials can be applied for different advanced applications. The bioactivity of the obtained materials will be studied and published as a second part of this article.