IRM pour l’Ingénierie

Thermal characterization at high temperature and of complex materials

Implementation of thermal measurement techniques by inverse methods adapted to increasingly complex materials and/or under extreme thermal conditions, where heat transfer modes are strongly coupled.

Specificities

  • Characterization of complex materials : anisotropic, porous, semi-transparent, super-insulating, etc
  • High-temperature characterization of various materials: composites, metals, titanium alloys, ceramics, liquid glasses, etc
  • Development of interaction models between conduction, convection and radiation in connection with experimental benches

Application sectors

  • Heat transfer in building conception (fibrous insulation, super-insulating materials, etc)
  • Glass and Steel processes (forming, etc)
  • Thermal barriers (ceramics, composite materials, etc)
  • High temperature heat recovery (ceramic absorber or heat exchanger, etc)

Keywords

  • Complex materials
  • High temperatures
  • Thermal coupling
  • Inverse methods
  • Diffusivimetry
  • Calorimetry
  • Porosimetry
  • Permeametry

Middle and high temperature thermal characterization of materials

  • Thermal diffusivity measurement by Flash method:
    – Continuous CO2 laser CO2 – 100 W (150 W max.)
    – Vacuum tube furnace [20°C – 1800°C]
    – EM-CCD infrared matrix camera
    – Mounts and inverse models adapted to studied materials
  • Heat capacity measurement :
    – 3D drop sensor with 56 thermocouples on samples of 5700 mL max.
    – Heat flow differential scanning calorimeter (hf-DSC) with 20 thermocouples on samples of 450 mL max.
Banc de caractérisation thermique Haute température par Méthode Flash
High temperature characterization bench by Flash method

Thermal characterization of complex materials

  • Simultaneous measurement of thermal conductivity and diffusivity :
    – By three-layer flow-metric method
    – By parallel hot-wire method
    – Under air furnace [20°C – 1000°C]
    – Mounts and inverse models adapted to studied materials
  • Porosity measurement by helium pycnometry
  • Measurement of gas permeability
Perméamètre
Permeameter
  • High temperature characterization bench by Flash method
  • Conductivity measurement bench for insulating materials by three-layer method in vacuum chamber

Study of the radiation absorbency of ceramic foams

Implementation of thermal characterization method of ceramic foams, more or less porous, in which the conductive-radiative heat transfer coupling is strong. Experimental measurements by Flash method [20°C – 800°C] coupled to a direct model by Finite volumes (conduction) -Monte Carlo method (radiation).

Exemples de mousses structurées et stochastiques étudiées (SiC et SiSiC)
Examples of some studied structured and stochastic foams (SiC et SiSiC)

Development of an inverse analytical model for the parallel hot-wire method

Improvement of the simultaneous estimation of thermal conductivity and diffusivity between 20°C and 1000°C, with the consideration of thermal contact resistances. Variant method with 2 temperature measurements for anisotropic materials.

Dispositif de mesure par fil chaud parallèle au sein du four à 1000°C.
Parallel hot-wire measurement device in the furnace at 1000°C

Complex materials
Yves Jannot
yves.jannot@univ-lorraine.fr 

High temperatures 
Vincent Schick
vincent.schick@univ-lorraine.fr