What are extensive properties in thermodynamics

Thermophysical material properties

The working group has been dealing with the determination of thermophysical material properties of solids for many years. In various parameter ranges of temperature, pressure and gas atmosphere, commercial and in-house developed devices are used to characterize a wide variety of materials (metals, plastics, building and insulating materials) and structures (compact bodies, foams, granulates, layers). Measured variables are thermal and thermal conductivity, specific heat capacity, thermal expansion and radiation properties (transmission, reflection).

The working group has dealt specifically with the following topics, among others

  • Design and construction of measuring equipment to determine the thermal conductivity of insulation materials at temperatures up to 1,600 ° C and under different gas atmospheres, supported by numerical simulation
  • Thermal conductivity of insulation materials at high temperatures - evaluation and comparison of different measurement methods
  • Further development of measurement methods for determining the thermal conductivity of metal and ceramic foams
  • Model description of the heat transport in porous media
  • Investigations into the influence of the gas atmosphere and the Knudsen effect on the thermal conductivity of porous media
  • Participation in interlaboratory comparisons within the framework of the thermophysics working group (temperature and thermal conductivity, thermal expansion, specific heat capacity) for quality assurance
  • Thermophysical properties of thermal barrier coatings based on Ln2Zr2O7-Y2O3Systems as well as spray coatings
  • High-temperature insulation materials when used in industrial furnaces with a hydrogen-containing protective gas atmosphere

Further development

A special plate apparatus for determining the thermal conductivity of insulation materials from vacuum (10-5 bar) up to the high pressure range (100 bar) at temperatures up to approx. 900 ° C is currently in the test phase. A measuring device for the investigation of the thermal accommodation coefficient on ceramic surfaces is being set up.

Furthermore, the development of methods for determining the thermophysical material properties of liquids, gases and supercritical fluids in a wide temperature range is increasingly planned.

Project support is possible in the following ways:

  • Measurement of thermophysical material data of solids with different structures
  • Parameter studies on the influence on thermophysical material data
  • Method development and comparison of different measurement methods
  • Model evaluation and development for heat transport in porous structures
  • Search for comparative data of thermophysical material data from an existing, very extensive material data collection

Contact person:

Lampadius-Bau, Gustav-Zeuner-Straße 7, room 304

Phone +49 3731 39-2468
Fax +49 3731 39-3963
Rhena [dot] Wulfttd [dot] tu-Freiberg [dot] de