Structural and magnetic Materials

Structural materials play a prominent role as construction materials in a wide variety of applications. The mechanical properties of metals like steels and aluminium alloys are strongly determined by the microscopic structure formed during the production process. The aim of our research is to obtain a fundamental understanding of the physical mechanisms that control the structure evolution of these structural materials during the various phase transformations that occur during production or use. The relevant phase transformations are solidification, and various solid-state phase transformations that involve grain nucleation, diffusional grain growth, precipitation behaviour and martensitic transformations. We apply synchrotron X-ray diffraction and neutron scattering techniques to obtain in-situ information on the grain nucleation and growth during the phase transformations. In addition to structural materials we also study magnetic materials by neutron scattering and muon-spin rotation techniques. It is by virtue of the spin of the neutron and muon that we are able to study the magnetic structure in materials on a scale from atoms up to microns in considerable detail.

Synchrotron X-ray diffraction patterns of the aluminium alloy with solute titanium and added TiB2 particles at different stages of the solidification process during continuous cooling: (a) the liquid phase, (b) the mixed liquid-solid phase, and (c) the solid phase.

If you have enquiries about our research please contact Niels van Dijk (see webpage)

Recent projects on structural materials:

  • Stability of retained austenite in TRIP steels during cooling
  • Grain refinement during solidification of aluminium alloys
  • Transformation kinetics of the austenite to ferrite transformation in steel
  • Self healing aluminium
  • Self healing steel
  • Nucleation theory
  • Maraging steel

Recent projects on magnetic materials:

  • Ferromagnetic systems in the vicinity of a quantum critical point
  • Frustrated magnetic systems

Main experimental techniques:

  • Synchrotron radiation
  • Neutron scattering
  • Muon spin rotation

Popular Press:

  • Highlights ESRF 2007: Monitoring metastable grains in steel [WWW]
  • Highlights ESRF 2005: Synchrotron study of solidification in aluminium alloys [WWW]
  • Highlights ESRF 2002: Synchrotron study of phase transformations in steel [WWW]
  • Annual Report ISIS 1998: Muon study on strongly correlated f-electron intermetallics
  • Annual Report PSI 1997: Muon study on the magnetic properties of RNi5
  • The Orange Book, Dutch neutron and muon science 2000-2003 [PDF]
  • Outlook TU Delft 2004: Synchrotron study of phase transformations in steel [PDF]

Presentation:

  • Modern Tools for Materials Science workshop in Delft (October 2005) [PowerPoint]

PhD Thesis:

  • Serdar Sakarya (2007), Magnetic properties of uranium based ferromagnetic superconductors [PDF]
  • Naveed Iqbal (2005), Solidification, real-time investigation of grain nucleation and growth during liquid to solid phase transformation of aluminium alloys [PDF]
  • Erik Offerman (2003), Evolving microstructures in carbon steel, a neutron and synchrotron radiation study [PDF]
  • Carlo Kaiser (2001), Diffusion, reorientation and small magnetic fields studied by muSR [PDF]
  • Suzanne te Velthuis (1999), Phase transformations in steel, a neutron depolarization study [PDF]
  • Annemieke Mulders (1998), Complex magnetic phenomena in rare earth intermetallic compounds [PDF]

Dr. Ir. Niels van Dijk

Associate Professor FAME

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