Journal of the Korean Society for Heat Treatment (열처리공학회지)

The Korean Society for Heat Treatment (한국열처리공학회)
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A Study on the Precipitation Behavior of $L2_1$-type $Ni_2AlTi$ Phase in B2-Ordered NiAl System

B2-규칙 NiAl계에 $L2_1$형 $Ni_2AlTi$상의 석출거동에 관한 연구

  • Han, Chang-Suk (Dept. of Defense Science & Technology, Hoseo University)
  • 한창석 (호서대학교 국방과학기술학과)
  • Received : 2007.06.12
  • Accepted : 2007.07.03
  • Published : 2007.07.30
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Abstract

A transmission electron microscope (TEM) investigation has been performed on the precipitation of $L2_1$-type $Ni_2AlTi$ phase in B2-ordered NiAl system. The hardness after solution treatment is high in NiAl-Ti alloys suggesting the large contribution of solid solution strengthening in this alloy system. However, the amount of age hardening is not large as compared to the large microstructural variations during aging. At the beginning of aging, the $L2_1$-type $Ni_2AlTi$ precipitates keep a lattice coherency with the NiAl matrix. By longer periods of aging $Ni_2AlTi$ precipitates lose their coherency and change their morphology to the globular ones surrounded by misfit dislocations. Misfit dislocations, which are observed on {100} planes of H-precipitates have the Burgers vector of a <100> with a pure edge type. The lattice misfits of NiAl-$Ni_2AlTi$ system is estimated from the spacings of misfit dislocations to be 1.1% at 1273 K. The lattice misfits decrease with increasing aging temperature in this system.

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References

  1. D. B. Miracle: Acta Metall., 41 (1993) 649 https://doi.org/10.1016/0956-7151(93)90001-9
  2. R. T. Pascoe and C. W. A. Newey: Metal Sci. J., 2 (1968) 138 https://doi.org/10.1179/030634568790443477
  3. M. Yamaguchi, Y. Umakoshi and T. Yamane : Phil. Mag. A, 50 (1984) 205 https://doi.org/10.1080/01418618408244223
  4. M. V. Nathal : Ordered Intermetallics-Physical Metallurgy and Mechanical Behaviour, 213 (1992) 541
  5. K. Ishikawa, I. Ohnuma, R. Kainuma, K. Aoki and K. Ishida : Crystal chemistry of intermetallic compounds, (2004) 2
  6. R. D. Field, R. Darolia and D. E Lahrman : Scripta Metall., 23 (1989) 1469 https://doi.org/10.1016/0036-9748(89)90112-9
  7. N. C. Tso and J. M. Sanchez: MRS Symp. Proc., 133 (1989) 63
  8. M. H. Loretto and R. J. Wasilewski: Phil. Mag., 23 (1971) 1311 https://doi.org/10.1080/14786437108217004
  9. P. Veyssiere and R. Noebe : Phil. Mag. A, 65 (1992) 1 https://doi.org/10.1080/01418619208201475
  10. P. Veyssiere : Ordered Intermetallics-Physical Metallurgy and Mechanical Behaviour, 213 (1992) 165
  11. P. Villars and L. P. Calvert: Peason's Handbook of Crystallographic Data for Intermetallic Phases, (1985)
  12. 原田虞史,大野勝美,山崎道夫:日本金属準舎秋期大 舎講演概要, (1991) 337
  13. T. Kumeta and M. Enomoto : Scripta Materialia, 44 (2001) 481 https://doi.org/10.1016/S1359-6462(00)00619-9
  14. P. Nash and W. W. Liang : Metall. Trans. A, 16A (1985) 319
  15. W. J. Boettinger, L. A. Bendersky; E S. Biancaniello and J. W Cahn : Mater. Sci. Eng., 98 (1988) 273 https://doi.org/10.1016/0025-5416(88)90168-1
  16. B. P. Burton, J. E. Osburn and A. Pasturel : MRS Symp. Proc., 213 (1991) 107