Imperfections in the Directionally Solidified Structure of NiO-CaO Eutectic

  • B. J. Pletka


Imperfections in the microstructure of the directionally solidified NiO-CaO lamellar eutectic were examined by optical, scanning electron, and transmission electron microscopy. Lamellar terminations and mismatch boundaries were observed in all eutectic grains on transverse sections. The lamellar interfacial planes between the NiO and CaO phases were found to be approximately (111)NiO parallel to (111)CaO in agreement with previous work. However, the orientation of the lamellar habit plane was determined to vary from an exact {111} plane from electron diffraction studies. Analysis of Kikuchi line patterns in electron diffraction patterns also showed that random variations in orientation up to 2° occurred between adjacent lamellae about the growth direction. In order to accommodate such variations in orientation, sub-boundaries formed within individual lamellae.


Orientation Relationship Habit Plane Eutectic Alloy Lamellar Microstructure Directionally Solidify 
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Copyright information

© Plenum Press, New York 1986

Authors and Affiliations

  • B. J. Pletka
    • 1
  1. 1.Department of Metallurgical EngineeringMichigan Technological UniversityHoughtonUSA

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