Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Mechanical Properties of AlN/hBN Ceramic Composites

AlN/hBN 복합재료의 기계적 성질

  • Lee, Jaehyung (School of Materials Science and Engineering, Yeungnam University) ;
  • Ahn, Hyun-Wook (School of Materials Science and Engineering, Yeungnam University) ;
  • Yoon, Young-Sik (School of Materials Science and Engineering, Yeungnam University) ;
  • Cho, Myeong-Woo (School of Mechanical Engineering, Inha University) ;
  • Cho, Won-Seung (School of Materials Science and Engineering, Inha University)
  • Published : 2005.08.01
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Abstract

AlN-BN ceramic composites were fabricated and their mechanical properties were investigated. The relative density of hot-pressed composites decreased with increasing BN content, but over $99\%$ could be obtained with 30 $vol\%$ BN in AlN. YAG was formed in the composites and monolithic AlN as a second phase by the reaction between $Y_2O_3$, added as sintering aid, and $Al_2O_3$. As expected, Vickers hardness and Young's modulus decreased with increasing BN content. The three-point flexural strength also showed similar behavior decreasing from 500 MPa of monolith down to 250 MPa by the addition 30 $vol\%$ BN. However, interestingly, the standard deviation of the strength values decreased significantly as BN was added to AlN. As a result, the Weibull modulus of the AlN-30 $vol\% BN composite was 21.3, which was extremely high. Fractography and crack path studies revealed that BN platelets induced grain pull-out and crack bridging in a bigger scale during crack propagation. Consequently, fracture toughness increased as more BN was added, reaching 4.5 $MPa\sqrt{m}$ at 40 $vol\%$ BN.

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References

  1. K. S. Mazdiyasni, R. Ruh, and E. E. Hermes, 'Phase Characterization and Properties of AIN-BN Composites,' Am. Ceram. Soc. Bull., 64 [8] 1149-54 (1985)
  2. T. Kanai, K. Tanemoto, and H. Kubo, 'Hot-Pressed BN-AIN Ceramic Composites of High Thermal Conductivity,' Jpn. J. Appl. Phys., 20 [8] 683-87 (1990)
  3. T. Kusunose, T. Sekino, B. S. Kim, Y.-H. Choa, T. Nomoto, Y. Yamanoto, and K. Niihara, Materials Science Forum, 439 131-36 (2003)
  4. A. Lipp, K. A. Schwetz, and K. Hunold, 'Hexagonal Boron Nitride : Fabrication, Properties and Applications,' J. Eur. Ceram. Soc., 5 3-9 (1989) https://doi.org/10.1016/0955-2219(89)90003-4
  5. Y.-H. Lee, J.-G. Kim, W.-S. Cho, M.-W. Cho, E.-S. Lee, and J. Lee, 'Effect of h-BN Content on Microstructure and Mechanical Properties of AIN Ceramics(in Korean),' J. Kor. Ceram. Soc., 40 [9] 874-80 (2003) https://doi.org/10.4191/KCERS.2003.40.9.874
  6. K. Isomura, T. Fukuda, K. Ogasahara, T. Funahashi, and R. Uchimura, 'Machinable $Si_{3}N_{4}$-BN Composite Ceramics with High Thermal Shock Resistance, High Erosion Resistance,' pp. 624-34 in UNITECR '89 Proceedings, Edited by L. J. Trostel, Jr., American Ceramic Society, Westerville, OH, 1989
  7. M. W. Cho, D. W. Kim, E. S. Lee, W. S. Cho, J. Lee, D. S. Park, and T. Seo, 'Machinability Evaluation of $Si_{3}N_{4}$-hBN Composites for Micro Pattern Making Processes,' Key Eng. Mat., 264-268 869-72 (2004) https://doi.org/10.4028/www.scientific.net/KEM.264-268.869
  8. J. Lee, Y.-S. Yoon, W.-S. Cho, E.-S. Lee, and, M.-W. Cho, 'R-Curve Behavior and Mechanical Properties of Mica-Glass,' To be presented in the 4th China International Conference on High-Performance Ceramics, Chengdu, Sichuan Province, China, Oct. 23-26, 2
  9. Y. S. Yoon, S. W. Na, J. Lee, M.-W. Cho, E.-S. Lee, and W.-S. Cho, 'R-Curve Behavior of $Si_{3}N_{4}$-BN Composites,' J. Am. Ceram. Soc., 87 [7] 1374-77 (2004) https://doi.org/10.1111/j.1151-2916.2004.tb07740.x
  10. G. R. Antis, P. Chanticul, B. R. Lawn, and D. B. Marshall, 'Critical Evaluation of Indentation Techniques for Measuring Fracture Toughness : I. Direct Crack Measurement,' J. Am. Ceram. Soc., 64 [9] 533-38 (1981) https://doi.org/10.1111/j.1151-2916.1981.tb10320.x
  11. P. Chanticul, G. R. Antis, B. R. Lawn, and D. B. Marshall, 'Critical Evaluation of Indentation Techniques for Measuring Fracture Toughness : II. Strength Methods,' J. Am. Ceram. Soc., 64 [9] 539-43 (1981) https://doi.org/10.1111/j.1151-2916.1981.tb10321.x
  12. R. K. Bordia and G. W. Scherer, 'Overview No. 70-On Constrained Sintering-Part III. Rigid Inclusions,' Acta Metall., 36 [9] 2411-16 (1988) https://doi.org/10.1016/0001-6160(88)90191-5
  13. D. Green, 'An Introduction to the Mechanical Properties of Ceramics,' pp. 286-91, Cambridge University Press, Cambridge, 1998
  14. B. Lawn, Fracture of Brittle Solids, 2nd Ed., pp. 72-9, Cambridge University Press, Cambridge, 1993
  15. B. Lawn, Fracture of Brittle Solids, 2nd Ed., pp. 230-41, Cambridge University Press, London, Cambridge, 1993
  16. K. Niihara, 'Indentation Microfracture of Ceramics(in Jpn.),' Ceramics Japan, 20 [1] 12-8 (1985)
  17. Y. S. Yoon, H. W. Ahn, B. K. Koo, J. Lee, M.-W. Cho, E.-S. Lee, and W.-S. Cho, 'R-Curve Behavior of $Si_{3}N_{4}$-BN and AlN-BN Composites,' Presented in the 2nd Korea-Slovenia Joint Workshop on Advanced Materials, Pohang, Korea, Nov. 11. 2004