Synthesis, phase transformation and mechanical property of SiAlON ceramics from coal gangue

作者:
Hou X. , Yue C. , Guo M. , Wang X. , Zhang M. , Chou K.C.
作者单位:
University of Science and Technology Beijing, Metallurgical and Ecological Engineering School, Beijing, China , Shougang Environmental Protection Department, China , Peking University, College of Engineering, Department of Energy and Resources Engineering, Beijing, China
摘要:
A simple and efficient method for preparation of SiAlON ceramics including β-SiAlON, O'-SiAlON and AlN polytypoid (15R and 12H) using reduction-nitridation of coal gangue and reducing agents at 1800K for 6h was described. The phase transformation of SiAlON at various atmospheres was discussed from thermodynamic and experimental analysis. Thermodynamic calculation revealed that different SiAlON phases could be synthesized at 1800K with the suitable atmosphere parameter Y (Y = lg(PO2 /ρθ)--3 2 lg(PN2 / ρθ)). Low Y value was beneficial to synthesis of β-SiAlON. The experimental result showed that β-SiAlON ceramics with the content of 90% was fabricated at strong reductive atmosphere in flowing nitrogen. O'-SiAlON with the content of 85% can be synthesized in flowing nitrogen atmosphere. In view of AlN polytypoid, the suitable condition to produce 15R was flowing nitrogen and 12H was formed at a weak reductive atmosphere. The mechanical properties of SiAlON ceramics synthesized under optimum conditions, i.e., modules of rupture (MOR) at room temperature, have been reported.
语种:
EN,SR
DOI:
10.5937/JMMA1401047H
来源期刊:
Journal of Mining and Metallurgy. Section A: Mining
出版商:
University of Belgrade, Technical Faculty Bor
年,卷(期):
2014;50(1):47-55