Fabrication of TiAl Alloys by Mechanical Milling and Spark Plasma Sintering

기계적 분쇄화 및 스파크 플라즈마 소결에 의한 TiAl 합금의 제조

  • Kim, M.S. (Dept. of Materials Science & Engineering, Kumoh National Institute of Technology) ;
  • Kim, J.S. (Dept. of Materials Science & Engineering, Kumoh National Institute of Technology) ;
  • Hwang, S.J. (Department of Materials Science & Engineering, Daejin University) ;
  • Hong, Y.H. (Dept. of Application of Advanced Materials, Suwon Science College) ;
  • Oh, M.H. (Dept. of Materials Science & Engineering, Kumoh National Institute of Technology)
  • 김민수 (금오공과대학교 재료공학과) ;
  • 김준식 (금오공과대학교 재료공학과) ;
  • 황승준 (대진대학교 재료공학과) ;
  • 홍영환 (수원과학대학 신소재응용과) ;
  • 오명훈 (금오공과대학교 재료공학과)
  • Received : 2003.10.29
  • Published : 2004.01.30

Abstract

In the present study, newly developed spark plasma sintering(SPS) technique was introduced to refine the grain size of ${\gamma}$-based TiAl intermetallic compounds. Ti-46Al-1.5Mo and Ti-46Al-1.5Mo-0.2C(at%) prealloyed powders were produced by mechanical milling(MM) in high-energy attritor. The mechanically milled powders were characterized by XRD and SEM for the microstructural evolution as a function of milling time. And then, the MMed powders were sintered by both spark plasma sintering and hot pressing in vacuum (HP). After the sintering process, MM-SPSed specimens were heat-treated in a vacuum furnace (SPS-VHT) and in the SPS equipment(MM-SPS) for microstructural control. It was found from microstrutural observation that the microstructure consisting of equiaxed ${\gamma}$-TiAl with a few hundred nanometer in average size and ${\alpha}_2-Ti_3Al$ particles were formed after both sintering processes. It was also revealed from hardness test and three-point bending test that the effect of grain refinement on the hardness and bending strength is much higher than that of carbon addition. The fully lamellar microstructures, which is less than $80{\mu}m$ in average grain size was obtained by SPS-VHT process, and the fully lamellar microstructure which is less than $100{\mu}m$ in average grain size was obtained by MM-SPS for a relatively shorter heat-treatment time.

Keywords

Acknowledgement

Supported by : 금오공과대학교

References

  1. H. Lipsitt, High-Temperature Ordered Intermetallic Alloys, ed. by C. C. Koch, C. T. Liu and N. S. Stoloff, MRS, Pittsburg, PA, 39 (1985) 7
  2. Y. W. Kim and F. H. Froes, High Temperature Aluminides and Intermetallics, ed. by S. H. Huang, C. T. Liu, D. P. Pope and J. O. Stieger, TMS, Warrendale, PA, (1990) 465
  3. M. Yamaguchi and Y Umakoshi, Prog. Mater. Sci., 34 (1990) 1
  4. M. Yamaguchi and H. Inui, Structural Intermetallics, ed. by R. Darolia et. al, TMS, Champion, PA, (1993) 127
  5. Y. W. Kim, JOM, 46 (1994) 30
  6. M. Tokida, J. of the Soc. Powder Tech. Japan, 30 (1993) 790
  7. T. Tacheuchi, E. Betourne and M. Tabuchi, J. Mat. Sci., 34 (1999) 34
  8. N. Zavodov, A. V. Kozlov, S. N. Luzganov, V. P. Polishchuk and A. V. Shurupov, High Tepm., 37 (1999) 135
  9. J. F. Li, S. Satomi, R. Watanabe, M. Omori and T. Hirai, J. Euro. Cer. Soc., 20 (2000) 1795
  10. M. Omori, Mat. Sci. & Eng. A, 287 (2000) 183
  11. S. J. Kim, K. S. Cho and N. J. Park, J. Kor. Assoc. Cry. Growth, 11 (2001) 115
  12. K. S. Cho, S. J. Kim, S. H. Baek, H. J. Choi and J. G. Lee, J. Kor. Cer. Soc., 38 (2001) 687
  13. Z. H. Shan, H. Hashimoto, S. Sumi, Y. H. Park and T. Abe, Acta metal. Sinica, 11 (1998) 417
  14. Z. H. Shan, Z. M. Sun, H. Hashimoto, Y. H. Park and T. Abe, Mater. Trans. JIM, 40 (1999) 417
  15. J. S. Benjamin and T. E. Volin, Metall. Trans., 5 (1974) 1929
  16. Y. S. Song and T. H Kim, J. Kor. Inst. of Metals, 28 (1990), 111
  17. H. N. Lee, I. S. Jung, M. H. Oh, M. Yamaguchi and D. M. Wee, J. Kor. Inst. Met. & Mater., 40 (2002) 39
  18. H. N. Lee, D. R. Johnson, H. Inui, M. H. Oh, D. M. Wee and M. Yamaguchi, Intermetallics, 10 (2002) 841