Ceramics-Silikáty 58, (3) 223 - 226 (2014) |
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SYNTHESIS OF ALUMINUM OXYNITRIDE SPINEL POWDERS BY ALUMINOTHERMIC REACTION UNDER REDUCING CONDITIONS |
Qiu Wendong 1, Ruan Guozhi 1,2, Zhang Zhihui 2,
Ouyang Junhua 1,
Xu Guogang 2 |
1 Refracotory division, Shanghai baosteel industrial services Co., LTD., Baoshan Distirct,
Shanghai 201900, People s Republic of China
2 College of Materials Science and Engineering, Shandong University of Science and Technology,
Qingdao 266590, People s Republic of China
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Keywords: X-ray diffraction, ceramic; sintering, AlON |
Aluminum oxynitride spinel (AlON) powders were synthesized by aluminothermic reaction under reducing conditions
provided by N22O3 alumina micron-sized powders as
starting materials. The influence of Al/γ-Al2O3 ratio and sintering temperature on the phase composition and microstructure
of sintered samples was explored. The experimental results showed that when Al/γ-Al2O3 mass ratio equal to 3, AlON phase
with AlN as a minor phase can be formed at 1600oC using this method. And we attributed the presence of small amounts of
AlN to the displacement of oxygen atoms from AlON phases by nitrogen atoms at high temperature under carbon embedded
condition. At the same time, grains of AlON were tabular in shape and whiskers can be found in samples after sintered at
1600oC because of elevated amount o non-stoichiometric species (Al, Al2O, AlO) produced in strongly reducing atmosphere. |
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