Effect of impurities of Fe2O3 and TiO2 in bauxite on oxidation kinetics of β-SiAlON powders. (15th July 2022)

• Record Type: Journal Article
• Authors: Tian, Xuekun; Su, Kai; Ouyang, Deze; Gao, Jinxing; Jia, Quanli; Liu, Xinhong
• Is Part Of: Corrosion science. Volume 203(2022)
• Publication Date: 2022-07-15
• Subjects: β-SiAlON -- Impurities -- Oxidation kinetics -- Oxidation rate -- SEM; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110374
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: The oxidation kinetics of β-SiAlON with and without impurities synthesized using α-Al2 O3, Si, Al, Fe2 O3 or TiO2 powders at 1573 K in microwave sintering furnace, were investigated. The initial oxidation temperature of β-SiAlON with impurities was lower than that sample without impurities. In the initial oxidation stage at 1373–1473 K, the lattice deformation accelerated oxidation rate of β-SiAlON with impurities. However, in the final oxidation stage, the oxidation rate of β-SiAlON with impurities was much lower than that of reference sample, because impurities promote glass film formation on surface of β-SiAlON particles, reducing the chance of β-SiAlON reacting with O2 . Highlights: β-SiAlON with impurities was synthesized at 1573 K in microwave furnace. The impurities of Fe2 O3 and TiO2 promote the growth of β-SiAlON crystals. The impurities in β-SiAlON contributes to glass formation and mullite crystal growth during oxidation. In the initial oxidation stage, the impurities make β-SiAlON more vulnerable to oxidation. In the final oxidation stage, the impurities reduce the oxidation rate of β-SiAlON.