Electrically functional structural ceramics as heating conductor

Topic

© Fraunhofer IKTS
Ceramic glow plug, produced by 2-component ceramic injection molding in the EU project “CarCIM”.
© Fraunhofer IKTS
Ceramic glow plug for diesel engines.

Electrically conductive ceramic materials are advantageously used in heating processes under extreme conditions such as high temperatures, strong oxidation, chemically corrosive atmospheres or mechanical stress in the high-temperature range. For example, heating elements made of silicon carbide (SiC) have long been used in heat treatment plants. Targeted materials research has increased the variety of materials for ceramic heating conductor materials. In addition to R-SiC, Fraunhofer IKTS offers material solutions for S-SiC, Si-SiC or LPS-SiC, which, with their comparatively low electrical resistance, are already excellently suited as heating conductor materials at room temperature. In addition, composites of silicon carbide, silicon nitride and metal carbides or metal silicides can be used to selectively adjust electrical resistances from the insulator to the metal-like electrical conductor. Specific ceramics such as titanium suboxides, boron carbides, zirconium carbide or semiconducting mixed oxides offer the possibility to optimally serve various special functions and requirements at temperature ranging from 50 to 2200 °C.

 

Services offered

 

  • Selection of modern ceramic materials for customized heating processes
  • Development of ceramic heating elements for customized applications
  • Testing and characterization of the heating behavior of heat conductor materials and heating elements
  • Concepts, materials and components for multifunctional heating elements (e.g. heater + sensor + catalyst)

 

Technical equipment

 

  • Heating conductor test stand for application-related testing up to 1600 °C under air
  • Test bench for testing heating conductor materials up to 2200 °C under vacuum
  • Measurement of electrical resistance up to 1400 °C argon/nitrogen/air
  • Production of heating conductor components and parts

 

Areas of application / references

 

  • Ceramic glow plug for diesel engines
  • Linear evaporator elements made of S-SiC with dual function
  • Zirconium carbide heating elements