A large number of different high-temperature materials is used in furnace construction, such as refractory linings, high-temperature steel alloys, heating elements or kiln furniture.
The exact knowledge of their high-temperature properties is a prerequisite for making an optimal material choice. For example, these properties are used in the calculation of material indices, which enable materials to be evaluated with regard to specific requirements.
The application-related properties of high-temperature materials should be determined under operating conditions. With the help of the measured data, thermal processes are to be designed and development needs for new high-temperature materials identified.
Refractory materials are heterogeneous on a size scale of a few millimetres. Large test volumes are required to obtain reproducible measurement data. This requires the development of suitable measurement concepts. Lifetime and CO2 footprint are also to be estimated on the basis of the data obtained.
The HTL is developing three new test rigs for high-temperature characterisation:
1. Measurement of corrosion: TOM_chem
• For corrosive gases, particles and vapours
• Variable gas generation with burners and gas mixers
• In-situ weighing
• Test chamber for large samples
2. Measurement of mechanical properties: TOM_mech
• Flexural strength, fracture toughness
• Creep
• Tribology
• Dynamic mechanical analysis
3. Measurement of thermomechanical properties: TOM_wave
• Thermal cycling, thermal shock test
• CO2 laser heating for extreme heating rates
• Acoustic crack detection
• Thermal conductivity, emissivity, coefficient of thermal expansion
Fraunhofer ISC, Center for High Temperature Materials and Design HTL, Bayreuth