Korean Journal of Metals and Materials (대한금속재료학회지)

The Korean Institute of Metals and Materials (대한금속재료학회)
권호 표지

Microstructure of Precipitation Strengthened Ll2-type Co3Ti Intermetallic Compound

  • Han, Chang-Suk (Dept. of Defense Science & Technology, Hoseo University) ;
  • Chun, Chang-Hwan (Dept. of Defense Science & Technology, Hoseo University) ;
  • Han, Seung-Oh (Institute of Fusion Technology, Hoseo University)
  • Received : 2009.04.08
  • Published : 2009.11.25
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Abstract

The $Co_{3}Ti$ phase hardens appreciably by the fine precipitation of disordered fcc Co-rich phase upon aging after quenching from solution annealing temperature. Transmission electron microscope (TEM) observations revealed that the precipitates are platelet in shape, lying nearly parallel to the {100} planes of the $Ll_{2}$-ordered matrix, and perfectly coherent with the matrix lattice at the beginning of aging. The high temperature strength increases appreciably with the fine precipitation of disordered Co-rich phase over the whole temperature range investigated. TEM observations of the under-aged and deformed alloys revealed that superdislocations are pinned by precipitates indicating an attractive interaction between dislocations and precipitates. In the over-aged state, thin twins are introduced in the fcc Co-rich precipitates during deformation.

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References

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