You will find brief explanations on important technical terms from the area of high-temperature technology in our glossary.
Molybdenum disilicide is an intermetallic compound of molybdenum and silicon (Mo + 2 Si -> MoSi2). It is a material that is extruded to heating elements in different shapes or geometries by the powder-metallurgic method. Heating elements of MoSi2 are resistance heating elements.
The intermetallic compound is a suitable material for high-temperature applications due to its high melting temperature of 2030°C and its outstanding oxidation resistance. MoSi2 also has a high hardness and corrosion resistance and is situated between metallic super-alloys and ceramic materials in terms of structural applications in high-temperature technology.
MoSi2 is corrosion resistant up to 1800°C, mostly due to the formation of an SiO2-protective layer. It forms at above 1000°C and is just a few µm thick. As compared to the ceramic materials, the silicides are characterised by high heat conductivity and electrical conductivity. The high temperature change resilience permits faster heating up and cooling down. Due to the barely existing wear of the heating elements, a long heating element service life can be achieved.
"MoSi2-pest" is an effect occurring in the temperature range between approx. 300°C and 700°C. In this temperature range, heating elements of molybdenum disilicide (MoSi2) sometimes show strong oxidation with powdery disintegration of the material. One possible cause of this is in the intercrystalline disintegration that is facilitated by porosity and the structure. This disintegration may be prevented by a high density and a very slow porosity. In processes where longer hold times at low temperatures are needed, a heating element must fulfil particular demands. MolyCom®-Hyper 1800AP (Anti-Pest) does so.