Phase Transformations in Materials


Learning objectives:

Students are familiar with a generalized scheme of phase transformations important in materials science and engineering. This includes qualitative and quantitative description of thermodynamics and kinetics of phase transformations. The students are able to apply their fundamental knowledge in order to describe important phase transformations and to deduce properties of materials undergoing these transformations.


  • General considerations on phase transformations
  • Thermodynamic and kinetic fundamentals (material provided for self-study)
  • Single-component systems
  • Solidification and allotropic transformations (discontinuous)
  • Continuous phase transitions, e.g. ferroic transformations
  • Multi-component systems
  • Reconstructive transformation (changes are achieved by long-range diffusion)
    • Spinodal decomposition (change in composition, not in crystal structure)
    • Precipitation (change in composition and crystal structure from one parent phase into a two-phase microstructure)
    • Eutectic reaction (invariant reaction with change in composition and crystal structure resulting in a two-phase microstructure)
    • Peritectic reaction (invariant reaction with change in composition and crystal structure from two parent phases to a single phase)
  • Displacive transformation (no long-range diffusion and changes in crystal structure are achieved by deformation)
    • Shear transformation
    • Dilation transformation
    • Transformation by shuffling
  • Intermediate transitions (no long-range diffusion or only of some of the species)
    • Order transition (symmetry break in crystal structure by resembling site occupation, no change in total composition)
    • Massive transformation (change in crystal structure without change in total composition)
    • Bainite formation and Widmannstätten ferrite

Work Load

lectures: 36 h

private studies: 64 h


Powerpoint slides will be distributed via the ILIAS system.

Detailed information are available for different sub topics of the lecture from:

D. A. Porter, K. E. Easterling, M. Y. Sherif: “Phase transformations in metals and alloys”, CRC Press (2009)

H.K.D.H. Bhadeshia: “Diffusional formation of ferrite in iron and its alloys” in Progress in Materials Science 29 (1985) 321-386 [currently not available from KIT network but maybe accessed by LEA]

H.K.D.H. Bhadeshia, R.W.K. Honeycomb: “Steels: microstructures and properties”, Butterworth-Heinemann imprint by Elsevier (2017) [free online access from within KIT network]

H.K.D.H. Bhadeshia: “Bainite in steels: transformations, microstructure and properties”, Institute of Materials, London (1992)

R.W. Cahn, P. Haasen (Editoren): „Physical Metallurgy“, Serie, North Holland und andere (1996)

J. Freudenberger: „Skript zur Vorlesung Physikalische Werkstoffeigenschaften“, IFW Dresden (2004) [public domain]


Details about the lecture are distributed via: