Syntheses and characteristics of ultrafine AlN powder by carbothermal reduction-nitridation
WEI Xin1, ZHANG Hao2, SUN Dengqiong2, TIAN Chenguang2, LIU Xiangyu1, CUI Song3, TANG Wenming1
1. School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China; 2. Hefei Shengda Electronic Technology Industry Co. Ltd., Hefei 230088, China; 3. 43 Institute, China Electronics Technology Group Corporation, Hefei 230088, China
Abstract：The porous precursors were fabricated by extruding the mixture of superfine Al2O3 powder, nano carbon black and organic binder, and then adhesives-discharging. The precursors were calcined at high temperature to form AlN via the carbothermal reduction-nitridation reaction. Finally, the residual carbon was removed from the AlN calcined bodies and the AlN powder was obtained. Morphology, crystallinity, grain size, average particle size and the O, N and C contents of the AlN powder were investigated. The results show that the precursor has a porous structure with a high special surface area and spherical pores after adhesives-discharging at 360 ℃ for 2 h. After calcining at 1 650 ℃ and above, the product is composed of AlN, no Al2O3 residues is detected, indicating fulfillment of the AlN synthesis process. This experimental result agrees well with the thermodynamic calculation. The decarburization temperature has the greatest effect on the C content of the AlN powder and the feed rate is in the second place. The AlN powder synthesized by calcining at 1 700 ℃ for 12 h and decarburizing at 700 ℃ under the conditions of the pure oxygen atmosphere and the feed rate of 4 kg/h has a composition of 0.77% O, 33.42%N and 323×10-6 C. The powder also has a high degree of sphericility, a narrow particle size distribution and an average particle size (d50) as low as 1.36 μm. Such characteristics of the AlN powder are close to those of the foreign similar products.
[1] YOSHIKAZU K, MASAKI I, ATSUO Y.Low temperature synthesis of AlN by addition of various Li-salts[J]. Journal of European Ceramic Society, 2004, 24(15/16): 3801-3806. [2] MUSSLER B H.Advanced materials & powders[J]. American Ceramic Society Bulletin, 2000, 79(6): 45-47. [3] SHEPPARD L M.Aluminum nitride: a versatile but challenging material[J]. American Ceramic Society Bulletin, 1990, 69(11): 1801-1812. [4] ZHOU Heping, LIU Yaocheng, WU Yin.Development of aluminum nitride ceramics[J]. Journal of the Chinese Ceramic Society, 1998, 26(2): 517-522. [5] TUMMALA R R.Ceramic and glass-ceramic packaging in the 1990[J]. Journal of the American Ceramic Society, 1991, 74(5): 895-895. [6] 张浩, 崔嵩, 何金奇. 高性能氮化铝粉体技术发展现状[J]. 真空电子技术, 2015(5): 14-18. ZHANG Hao, CUI Song, HE Jingqi.Technology development status of high performance aluminum nitride powder[J]. Vacuum Electronics, 2015(5): 14-18. [7] KOMEYA wK. Synthesis of AlN by direct nitridation of aluminum alloys[J]. Journal of the Ceramic Society of Japan, 1993, 101(5): 1317-1323. [8] KIMURA I.Synthesis of aluminum nitride powder by carbothermic reduction[J]. Journal of Materials Science Letters, 1989, 8(1): 303-306. [9] 邹东利, 阎殿然, 何继宁, 等. AlN陶瓷粉末的主要制备方法及展望[J]. 山东陶瓷, 2006, 29(4): 10-13. ZOU Dongli, YAN Dianran, HE Jining, et al.The main preparation methods and prospect of AlN ceramic powder[J]. Shandong Ceramics, 2006, 29(4): 10-13. [10] VIRKAR A V, BARRETT J T, CUTLER R A.Thermodynamic and kinetic effects of oxygen removal on the thermal conductivity of aluminum nitride[J]. Journal of American Ceramic Society, 1989, 72(1): 2031-2042. [11] QIN Mingli, QU Xuanhui, LIN Jianliang, et al. Synthesis of ultrafine aluminum nitride powder by a low-temperature carbothermal reduction process[J]. Key Engineering Materials, 2002, 224/226(5): 531-534. [12] MAO Xixi, LI Jun, ZHANG Hailong, et al.Synthesis of AlN powder by carbothermal reduction-nitridation of alumina/carbon black foam[J]. Journal of Inorganic Materials, 2017, 32(10): 1115-1119. [13] WANG Qi, GE Yiyao, KUANG Jianlei, et al.Effects of additives on the synthesis of spherical aluminum nitride granules by carbothermal reduction-nitridation process[J]. Journal of Alloys & Compounds, 2017, 696(5): 220-225. [14] QIN Mingli, DU Xueli, WANG Jian, et al.Influence of carbon on the synthesis of AlN powder from combustion synthesis precursors[J]. Journal of the European Ceramic Society, 2009, 29(4): 795-799. [15] 巴伦. 纯物质化学手册[M]. 第3版. 程乃良, 牛四通, 徐桂英, 译. 北京: 科学出版社, 2003: 42, 48, 209, 403, 1081. Ballon. Thermochemical Date of Pure Substances[M]. 3rd Edition. CHENG Nailiang, NIU Sitong, XU Guiying, translated. Beijing: Science Press, 2003: 42, 48, 209, 403, 1081. [16] TOKUYAMA Co. Ltd. High purity aluminum nitride powder [EB/OL]. http://www.tokuyama.co.jp/business/specialtyproducts/ shapal/products/aln_powder_granules.html, 2018-04-19.
2018, Vol. 23 
