Breviary Technical Ceramics



 Intergranular Corrosion

The important corrosion mechanism here is the dissolution of the glassy/crystalline material which is present between the grains, particularly in liquid phase sintered materials (LPS) such as LPSSIC, LPSN, LPBN or Al2O3 with < 99.5 % Al2O3 content.
The rate of corrosion depends on the solubility product, L, of those ions in the intermediate phase that are relevant to corrosion.
Intergranular corrosion can be significantly reduced through the use of suitable intermediate phases with low solubility products, or by enlarging the grains in the microstructure, which is associated with a reduction in the grain boundary area.
Solid-phase sintered materials (S-Al2O3, SSIC and SSN) and hot pressed materials (HP-Al2O3, HPSIC etc.) show almost no susceptibility to corrosion.


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