A focal point of the Fraunhofer-Center HTL is the optimization of the heat treatment processes used in manufacturing ceramics, metals and metal-ceramic composites ,such as drying, binder burnout, pyrolysis, sintering or melt infiltration. Thus, time-temperature cycles can be improved as well as the furnace atmosphere or the set-up of the charge in the industrial furnace. The optimization goal is to receive high and reproducible product quality with optimized material-, energy- and cost efficiency of thermal processes (see Project EnerTHERM).
Fraunhofer-Center HTL develops ThermoOptical Measuring devices (TOM), in which the industrial heat process is imitated in the laboratory. TOM-devices are able to provide all relevant industrial atmospheres: gas burner atmosphere, air, inert gases, forming gas, hydrogen, vacuum, overpressure, etc. They are equipped with detectors monitoring material changes with high accuracy during the heat treatment. In addition, a thermophysical characterization of materials can be performed. Measuring quantities are amongst others thermal expansion, sintering shrinkage, warpage, thermal conductivity, emissivity, heat capacity, heat of reaction, weight change, gas emission, sound emission, wetting, creep, viscosity and thermal shock resistance. In contrast to conventional methods for thermal analysis, the TOM-systems use a sample volume of about 10 to 100 cm³. With this, properties of small components, composite materials or heterogeneous materials are reproducibly measurable during heat treatment.
The data measured are parameterized – in particular the kinetics of thermally activated reactions are described with robust models – and then used in FE simulations to optimize the heat treatment on the computer. In the FE models the interaction between the industrial furnace and the charge is taken into account so that the laboratory results can be transferred to the production scale. In addition, the Fraunhofer-Center HTL offers methods for investigating temperature distribution, furnace atmosphere and energy balance of production furnaces (see Industrial Furnace Analysis). These data can also be transferred to the FE models and used for process optimization with respect to product quality and energy efficiency.