Fabrication of Aluminum Oxynitride Transparent Ceramics by Carbothermal Reduction Nitridation Processing

doi:10.3724/SP.J.1077.2010.00678

Abstract

Abstract:

Aluminum oxynitride (AlON) powders were firstly prepared by carbothermal reduction and nitridation processing with g-Al₂O₃as starting material and carbon black (C) as a reducing agent and then AlON transparent ceramics were fabricated by gas-pressure sintering technique under nitrogen atmosphere. The effects of reactive temperature, holding time, and C content on the resultant phase compositions were investigated systematically by XRD. The microstructure of AlON transparent ceramics was observed by EPMA. The experimental results indicate that the CTRN processing for AlON formation is thermodynamically controlled and both reactive temperature and holding time are crucial to the reactive progress. The CTRN reaction begins at 1300℃ and finishes at 1700℃ with most of AlON and a trace of AlN. The AlN content further decreases with increasing reactive temperature while AlN phase can not disappear even at 1750℃ for 4h. With the as-prepared AlON powders as starting materials, AlON transparent ceramics can be fabricated by gas-pressure sintering technique at 1950℃ for 6h. The fabricated AlON transparent ceramics presents uniform microstructure with an average grains size of 50 mm.

Key words: aluminum oxynitride (AlON), powders, transparent ceramics, carbothermal reduction and nitridation processing

CLC Number:

TQ174

LIU Xue-Jian, YUAN Xian-Yang, ZHANG Fang, HUANG Zheng-Ren, WANG Shi-Wei. Fabrication of Aluminum Oxynitride Transparent Ceramics by Carbothermal Reduction Nitridation Processing[J]. Journal of Inorganic Materials, 2010, 25(7): 678-682.

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