DOI QR코드

DOI QR Code

Fabrication of Porous Mo-Cu by Freeze Drying and Hydrogen Reduction of Metal Oxide Powders

금속산화물 분말의 동결건조 및 수소환원에 의한 Mo-Cu 다공체 제조

  • Kang, Hyunji (Department of Materials Science and Engineering, Seoul National University of Science and Technology) ;
  • Han, Ju-Yeon (Department of Materials Science and Engineering, Seoul National University of Science and Technology) ;
  • Oh, Sung-Tag (Department of Materials Science and Engineering, Seoul National University of Science and Technology)
  • 강현지 (서울과학기술대학교 신소재공학과) ;
  • 한주연 (서울과학기술대학교 신소재공학과) ;
  • 오승탁 (서울과학기술대학교 신소재공학과)
  • Received : 2018.12.20
  • Accepted : 2019.01.26
  • Published : 2019.02.28

Abstract

In this study, porous Mo-5 wt% Cu with unidirectionally aligned pores is prepared by freeze drying of camphene slurry with $MoO_3-CuO$ powders. Unidirectional freezing of camphene slurry with dispersion stability is conducted at $-25^{\circ}C$, and pores in the frozen specimens are generated by sublimation of the camphene crystals. The green bodies are hydrogen-reduced at $750^{\circ}C$ and sintered at $1000^{\circ}C$ for 1 h. X-ray diffraction analysis reveals that $MoO_3-CuO$ composite powders are completely converted to a Mo-and-Cu phase without any reaction phases by hydrogen reduction. The sintered bodies with the Mo-Cu phase show large and aligned parallel pores to the camphene growth direction as well as small pores in the internal walls of large pores. The pore size and porosity decrease with increasing composite powder content from 5 to 10 vol%. The change of pore characteristics is explained by the degree of powder rearrangement in slurry and the accumulation behavior of powders in the interdendritic spaces of solidified camphene.

Keywords

References

  1. Y.-L. Shen, A. Needleman and S. Suresh: Metall. Mater. Trans. A, 25 (1994) 839. https://doi.org/10.1007/BF02665460
  2. H. Kang and S.-T. Oh: J. Korean Powder Metall. Inst., 25 (2018) 322 (Korean). https://doi.org/10.4150/KPMI.2018.25.4.322
  3. J. L. Johnson and R. M. German: Metall. Mater. Trans. A, 32 (2001) 605. https://doi.org/10.1007/s11661-001-0077-y
  4. W. S. Wang and K. S. Hwang: Metall. Mater. Trans. A, 29 (1998) 1509. https://doi.org/10.1007/s11661-998-0366-9
  5. K. C. Jeon, B. S. Kim, Y. D. Kim, M.-J. Suk and S.-T. Oh: Int. J. Refract. Met. Hard Mater., 53 (2015) 32. https://doi.org/10.1016/j.ijrmhm.2015.04.021
  6. T. Fukasawa, M. Ando, T. Ohji and S. Kanzaki: J. Am. Ceram. Soc., 84 (2001) 230. https://doi.org/10.1111/j.1151-2916.2001.tb00638.x
  7. K. Araki and J. W. Halloran: J. Am Ceram. Soc., 88 (2005) 1108. https://doi.org/10.1111/j.1551-2916.2005.00176.x
  8. S. Deville: Adv. Eng. Mater., 10 (2008) 155. https://doi.org/10.1002/adem.200700270
  9. S.-T. Oh, S.-Y. Chang and M.-J. Suk: Trans. Nonferrous Met. Soc. China, 22 (2012) s688. https://doi.org/10.1016/S1003-6326(12)61787-7
  10. O. Mengual, G. Meunier, I. Cayre, K. Puech and P. Sanbre: Talanta, 50 (1999) 445 https://doi.org/10.1016/S0039-9140(99)00129-0
  11. M. Wi niewska: Powder Technol., 198 (2010) 258. https://doi.org/10.1016/j.powtec.2009.11.016
  12. W. V. Schulmeyer and H. M. Ortner: Int. J. Refract. Met. Hard Mater., 20 (2002) 261. https://doi.org/10.1016/S0263-4368(02)00029-X
  13. G. Fierro, M. Lojacono, M. Inversi, P. Porta, R. Lavecchia and F. Cioci: J. Catal., 148 (1994) 709. https://doi.org/10.1006/jcat.1994.1257
  14. K. Araki and J. W. Halloran: J. Am. Ceram. Soc., 87 (2004) 2014. https://doi.org/10.1111/j.1151-2916.2004.tb06353.x
  15. D. R. Uhlmann, B. Chalmers and K. A. Jackson: J. Appl. Phys., 35 (1964) 2986. https://doi.org/10.1063/1.1713142
  16. S. Deville, E. Maire, G. Bernard-Granger, A. Lasalle, A. Bogner, C. Gauthier, J. Leloup and C. Guizard: Nature Mater., 8 (2009) 966. https://doi.org/10.1038/nmat2571