With regard to the production of furnaces and insulations CFC composite materials have become the centre of attention in addition to the traditional metal materials. They are absolutely non-warping in case of temperature fluctuations, considerably more lightweight and, hence, also lead to a reduction of energy consumption on account of the lower mass to be heated. State-of-the-art production methods mean that CFC components are available in almost any shape today: Various profiles, threaded rods, nuts and plates are already available as standard products in many different sizes.

CFC materials are characterized by the following properties:

• high thermal stability (no embrittlement, no warping)
• high mechanical load-bearing capacity
• high thermal shock resistance
• high mechanical stability (pseudo-ductile breaking behaviour)
• high purity (up to < 10 ppm)
• high chemical resistance
• low density (approx. 1.6 g/cm³)

Moreover, graphite materials and carbon foams are also used for furnace lining.