Breviary Technical Ceramics



 Corrosion From Melts

The corrosion Mechanisms of ceramics exposed to inorganic, non-metallic melts (such as molten salts, oxides, slags or glasses) are different from those arising with molten metals. Non-metallic melts

The extent of the reaction between inorganic melts and ceramics depends on a large number of factors. The most important of these are:
  • the viscosity of the melt,
  • the acidity or basicity of the melt,
  • the chemical composition and solubility of the reaction products,
  • the chemical composition of the principal and secondary phases in the ceramic, and
  • how easily the ceramic is wetted by the melt.

If it is necessary for ceramic materials to withstand melts, in practice it is almost always necessary to rely on tests. Molten metals

In contrast to the oxide ceramics, non-oxide materials are more resistant to corrosion by metallic melts. Silicon nitride is not wetted by most melts, but is not resistant to molten copper in oxidising atmospheres. Due to its low wettability, boron nitride is very resistant to most molten metals.

Aluminium titanate
(ATI) displays high resistance, in particular to molten non-ferrous metals, again because it is not easily wetted.


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