Hostname: page-component-f7d5f74f5-47svn Total loading time: 0 Render date: 2023-10-02T21:52:22.165Z Has data issue: false Feature Flags: { "corePageComponentGetUserInfoFromSharedSession": true, "coreDisableEcommerce": false, "coreDisableSocialShare": false, "coreDisableEcommerceForArticlePurchase": false, "coreDisableEcommerceForBookPurchase": false, "coreDisableEcommerceForElementPurchase": false, "coreUseNewShare": true, "useRatesEcommerce": true } hasContentIssue false

Fabrication of machinable AlN–BN composites with high thermal conductivity by pressureless sintering turbostatic BN-coated AlN nanocomposite powders

Published online by Cambridge University Press:  31 January 2011

Takafumi Kusunose*
The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 562-0047, Japan
Tohru Sekino
The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 562-0047, Japan
Yoichi Ando
The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 562-0047, Japan
Koichi Niihara
The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 562-0047, Japan
a)Address all correspondence to this author. e-mail:
Get access


To impart machinability to hard and brittle AlN ceramics without losing their high thermal conductivity, a homogeneous dispersion of fine BN particles in an AlN matrix was investigated. A homogeneous dispersion of BN particles was obtained by pressureless sintering of turbostatic BN-coated AlN nanocomposite powder (AlN–BN nanocomposite powder), which was prepared by reducing and heating AlN particles containing a mixture of boric acid, urea, and carbon. Though AlN is slightly oxidized by boric acid during the reduction, the addition of carbon reduced the oxygen content of the AlN–BN composite powder by carbothermal reduction of the oxidized AlN particles. As a result, the thermal conductivity of the sintered material increased with decreasing oxygen content of the nanocomposite powder. AlN–BN nanocomposites containing more than 20 vol% BN showed high strength, machinability, and relatively high thermal conductivity in comparison with the conventional microcomposites.

Copyright © Materials Research Society 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)



1Borom, M.P., Slack, G.A., Szymaszek, J.W.: Thermal conductivity of commercial alumium nitride. Am. Ceram. Soc. Bull. 51, 852 1972Google Scholar
2Xu, G-F., Olorunyolemi, T., Wilson, O.C., Lloyd, I.K., Carmel, Y.: Microwave sintering of high-density, high thermal conductivity AlN. J. Mater. Res. 17, 2837 2002CrossRefGoogle Scholar
3Xu, G-F., Carmel, Y., Olorunyolemi, T., Lloyd, I.K., Wilson, O.C. Jr.: Microwave sintering and properties of AlN/TiB2 composites. J. Mater. Soc. 18, 66 1989CrossRefGoogle Scholar
4Tatami, J., Komeya, K., Meguro, T., Iwasawa, S., Komatsu, M.: Fracture behavior of high thermal conductive aluminum nitride. Ceram. Eng. Sci. Proc. 20, 411 1999CrossRefGoogle Scholar
5Kuramoto, N., Taniguchi, H., Aso, I.: Development of translucent aluminum nitride ceramics. Am. Ceram. Soc. Bull. 68, 883 1989Google Scholar
6Lee, R.R.: Development of high thermal conductivity aluminum nitride ceramic. J. Am. Ceram. Soc. 74, 2242 1991CrossRefGoogle Scholar
7Watari, K., Hwang, H., Toriyama, M., Kanzaki, S.: Low-temperature sintering and high thermal conductivity of YLiO2-doped AlN ceramics. J. Am. Ceram. Soc. 79, 1979 1996CrossRefGoogle Scholar
8Jackson, T., Virkar, A., More, K., Dinwiddie, R.: High-thermal-conductivity aluminum nitride ceramics: The effect of thermodynamic, kinetic, and microstructual factors. J. Am. Ceram. Soc. 80, 1421 1997CrossRefGoogle Scholar
9Luo, X., Li, J., Zhang, B., Li, W., Zhuang, H.: High thermal conductivity aluminum nitride substrates prepared by aqueous tape casting. J. Am. Ceram. Soc. 89, 836 2006CrossRefGoogle Scholar
10Weimer, A.W., Cochran, G.A., Eisman, G.A., Henley, J.P., Hook, B.D., Mills, L.K., Guiton, T.A., Knudsen, A.K., Nicholas, N.R., Volmering, J.E., Moore, W.G.: Rapid process for manufacturing aluminum nitride powder. J. Am. Ceram. Soc. 77, 3 1994CrossRefGoogle Scholar
11Yamakawa, T., Tatami, J., Komeya, K., Meguro, T.: Synthesis of AlN powder from Al(OH)3 by reduction–nitridation in a mixture of NH3–C3H8 gas. J. Eur. Ceram. Soc. 26, 2413 2006CrossRefGoogle Scholar
12Munir, Z.A., Cho, W-S., Cho, M-W., Lee, J-H.: Effects of h-BN additive on the microstructure and mechanical properties of AlN-based machinable ceramics. Mater. Sci. Eng., A 418, 61 2006Google Scholar
13Jin, H-Y., Wang, W., Gao, J-Q., Qiao, G-J., Jin, Z-H.: Fabrication and properties of machinable AlN-BN ceramic nanocomposites. Key Eng. Mater. 317-318, 637 2006CrossRefGoogle Scholar
14Kusunose, T., Sekino, T., Kim, B-S., Choa, Y-H., Nomoto, T., Yamamoto, Y., Niihara, K.: Properties of hot-pressed AlN/BN nanocomposites. Mater. Sci. Forum 439, 131 2003CrossRefGoogle Scholar
15Lipp, A., Schwetz, K.A., Hunold, K.: Hexagonal boron nitride: Fabrication, properties and applications. J. Eur. Ceram. Soc. 5, 3 1989CrossRefGoogle Scholar
16Brozek, V., Hubacek, M.: A contribution to the crystallochemistry of boron nitride. J. Solid State Chem. 100, 120 1992CrossRefGoogle Scholar
17Zhang, G-J., Yang, J-F., Ando, M., Ohji, T.: Nonoxide-boron nitride composites: In situ synthesis, microstructure and properties. J. Eur. Ceram. Soc. 22, 2551 2002CrossRefGoogle Scholar
18Zhang, G-J., Yang, J-F., Ando, M., Ohji, T., Kanzaki, S.: Reactive synthesis of alumina-boron nitride composites. Acta Mater. 52, 1823 2004CrossRefGoogle Scholar
19Goeuriot-Launay, D., Brayet, G., Thevenot, F.: Boron nitride effect on the thermal shock resistance of an alumina-based ceramic composite. J. Mater. Sci. Lett. 5, 940 1986CrossRefGoogle Scholar
20Kusunose, T., Sekino, T., Choa, Y-H., Niihara, K.: Fabrication and microstructure of silicon nitride/boron nitride nanocomposites. J. Am. Ceram. Soc. 85, 2678 2002CrossRefGoogle Scholar
21Niihara, K.: New design concept of structural ceramics-ceramic nanocomposites. J. Ceram. Soc. Jpn. 99, 974 1991CrossRefGoogle Scholar
22Zhao, J., Stearns, L.C., Harmer, M.P., Chan, H.M., Miller, G.A., Cook, R.E.: Mechanical behavior of alumina-silicon carbide “nanocomposites.” J. Am. Ceram. Soc. 76, 503 1993CrossRefGoogle Scholar
23Sekino, T., Nakajima, T., Ueda, S., Niihara, K.: Reduction and sintering of a nickel-dispersed-alumina composite and its properties. J. Am. Ceram. Soc. 80, 1139 1997CrossRefGoogle Scholar
24Oh, S-T., Sekino, T., Niihara, K.: Fabrication and mechanical properties of 5 vol% copper dispersed alumina nanocomposite. J. Eur. Ceram. Soc. 18, 31 1998CrossRefGoogle Scholar
25Ohji, T., Jeong, Y-K., Choa, Y-H., Niihara, K.: Strengthening and toughening mechanisms of ceramic nanocomposites. J. Am. Ceram. Soc. 81, 1453 1998CrossRefGoogle Scholar
26Kusunose, T.: Fabrication of boron nitride dispersed nanocomposites by chemical processing and their mechanical properties. J. Ceram. Soc. Jpn. 114, 167 2006CrossRefGoogle Scholar
27Cho, W-S., Piao, Z-H., Lee, K-J., Yoo, Y-C., Lee, J-H., Cho, M-W., Hong, Y-C., Park, K., Hwang, W-S.: Microstructure and mechanical properties of AlN-hBN based machinable ceramics prepared by pressureless sintering. J. Eur. Ceram. Soc. 27, 1425 2007CrossRefGoogle Scholar
28Slack, G.A., Tanzilli, R.A., Pohl, R.O., Vandersande, J.W.: The intrinsic thermal conductivity of AlN. J. Phys. Chem. Solids 48, 641 1987CrossRefGoogle Scholar
29Slack, G.A.: Nonmetallic crystals with high thermal conductivity. J. Phys. Chem. Solids 34, 321 1973CrossRefGoogle Scholar