Heads of the group:
Prof. Dr.-Ing. Michael Schütze
Tel.: +49 69 / 7564-337
E-mail: schuetze
Dr. Mathias Galetz
Tel.: +49 69 / 7564-397
E-mail: galetz
DFI-Stifter

Continuing Professional Development

Electrochemical Impedance Spectroscopy
Frankfurt am Main 2015-11-05 - 2015-11-06

High Temperature Materials Research Group

 


 

Microstructure of a high temperature alloyThe demand for environmentally and resources-friendly processes as well as higher efficiency in thermal plants and machinery requires an increase of operating temperatures. However, processes conducted at high temperatures and often in complex atmospheres lead to increasing demands on the resistance to high temperature corrosion of the materials used. The main research objectives of the "high temperature materials" group at DFI are material analysis and development in the field of aggressive, high temperature environments. Within this research field, we focus on the development of metallic and ceramic protective coatings and innovative material systems appropriate for extremely aggressive service conditions (e.g. chlorine, sulphur, bromine, vanadium, and carbon-rich environments) and operation temperatures up to 1800 °C.

Diffusion Coatings

In order to produce such coatings, the material surface is enriched with protective elements by diffusion, which later prevent substrate corrosion during high temperature exposure

  • Methods: Pack cementation (in-pack, out-of-pack, slurry)
  • Protective coatings for a better oxidation resistance of materials at high temperature in environments rich in water vapour, typical for gasification and combustion atmospheres
  • Slurry-based coatings for application on-site in plants or on machine parts

Slurry coating of a pressure pipe

Computational modelling of coatings and their lifetime

Computer simulation tools are used to predict the material behaviour during manufacturing as well as their lifetime during their operation at high temperatures

  • Modelling of layer growth and phase formation in the pack cementation process
  • Computer modelling of the influence of defects on the mechanical properties of thermal barrier coatings and oxide layers

High temperature light weight metals

The replacement of Ni-based alloys by lighter materials in aviation turbines can decrease the CO2 emissions

  • Determination and extension of the existing operation limits of intermetallic systems such as titanium aluminides
  • Thermal barrier coatings for intermetallic titanium aluminides
  • New materials for a "Beyond Nickel-based Superalloys" approach: Silicides

Functional high temperature coatings

Providing high temperature protective coatings with additional properties such as self-cleaning, thermal insulation or improved aerodynamics can increase the quality and the efficiency of different engineering processes

  • Self-healing "shark skin" coatings for turbines
  • Foam-like ceramic thermal barrier coatings

"Minimally-invasive" high temperature corrosion protection

Metal DustingNew developments show that a slight change in the chemical composition near the surface region of different materials induces a change in the reaction mechanisms and hence in their corrosion behaviour as well

  • Development of stable and protective alumina layers by using the halogen effect
  • Sn-modified surfaces for catalytic poisoning in metal dusting environments
  • Controlling chlorine corrosion by selective doping of coatings

Research for industry

The work group also shares its methods and experience with industry and offers professional support and advice regarding industrial material problems and their explanation

  • Materials selection for complex conditions
  • Characterization of high temperature oxidation and corrosion resistance
  • Development and testing of high temperature corrosion protection measures
  • Investigation of damage cases specific to high temperature processes

Characterisation and investigation methods:

  • X-Ray diffraction at DECHEMA-ForschungsinstitutIsothermal and cyclic exposure in different environments (e.g. air, water vapour, O2, H2, CO, H2S, SO2, HCl)
  • Thermogravimetric methods
  • Metallographic and microanalytical characterization (including water free sample preparation)
  • Scanning electron microscope with EDX
  • Transmission electron microscope with EDX
  • Atomic force microscope
  • Electron microprobe analysis
  • X-ray diffraction
  • Contact angle measurements
  • Optical emission spectrometer
  • Dilatometer
  • Melting furnaces for metals
  • Nanoindentation and micro-hardness
  • Mechanical testing under tension, compression and four-point-bending
  • Combined creep and corrosion tests

High temperature acousic emission measurement

© DECHEMA e.V. 1995-2014, Last update 11.03.2014