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Journal of Materials Science

, Volume 17, Issue 1, pp 225–234 | Cite as

Transformation toughening

Part 1 Size effects associated with the thermodynamics of constrained transformations
  • F. F. Lange
Papers

Abstract

The thermodynamics of the constrained phase transformation is presented with particular reference to size effects introduced by surface phenomena concurrent with the transformation, e.g., the formation of solid-solid surfaces (twins, etc.) and solid-vapour surfaces (microcracks). It is shown that these surface phenomena not only introduce a size-dependent energy term into the total free-energy change, but also reduce the strain energy associated with the transformation, which can result in a transformation at a temperature where ¦ΔGc¦, the chemical free energy change, is less thanUse, the unrelieved strain energy associated with the constrained transformation. The results of this analysis lead to a phase diagram representation that includes the size of the transforming inclusion. This diagram can be used to define the critical inclusion size required to prevent the transformation and/or to obtain the transformation, but avoid one or more of the concurrent surface phenomena.

Keywords

Polymer Free Energy Phase Diagram Phase Transformation Energy Change 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman and Hall Ltd 1982

Authors and Affiliations

  • F. F. Lange
    • 1
  1. 1.Structural Ceramics GroupRockwell International Science CenterThousand OaksUSA

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