1. Synthesis Ca-α-SiAlON powder by carbothermal reduction nitridation of colloidal sol-gel derived powder precursor.
- Author
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Amin, M., Ehsani, N., and Mozafarinia, R.
- Subjects
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SOL-gel processes , *NITRIDATION , *FOURIER transform infrared spectroscopy , *POWDERS , *LIME (Minerals) , *ATMOSPHERIC nitrogen - Abstract
Ca-α-SiAlON powder was prepared by carbothermal reduction nitridation process at nitrogen atmosphere without using high pressure and long holding time. The precursor was prepared by a novel colloidal sol-gel process consisting of silica, alumina, calcium oxide and carbon. The obtained powders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The XRD and SEM analysis results revealed that by heating at 1200 °C for 2 h, spherical particles consisting of amorphous calcium aluminosilicate liquid phase were formed. With increasing temperature to 1360 °C and held for 2 h, the spherical particles with the dominant phase of O–SiAlON were observed. Finally, as the temperature climbed to 1500 °C and held for 2 h, spherical particles disappeared and Ca-α-SiAlON was formed. The XRD analysis of the products showed that with increasing temperature from 1360 °C to 1500 °C, O–SiAlON, β-SiAlON and Ca-α-SiAlON were formed, respectively, and colloidal sol-gel method, due to the high homogeneity of the reactants, had a significant role in increasing the purity of Ca-α-SiAlON. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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