The usage of refractory coatings during casting is of great importance in terms of achieving high quality surface finish of castings. Refractory coatings withstand a higher temperature of liquid metal and act as a barrier between metal and mold or core by the help of the type of refractory.
The usage of refractory coatings prevents the metal penetration, sand staining, veining defects during casting. Therefore, surface quality improves.
The choice of refractory is decided upon casting type and foundry conditions.
Solvents of refractory paints are selected from water or alcohol varieties (IPA, ethyl alcohol, etc.) depending on the foundry conditions. Selection of refractory material (zircon, alumina silicate, etc.) is carried out by the casting type.
Typical coating applications are dipping, flow coating, spraying and brushing.
TECHNICAL PARAMETERS THAT DICTATE SELECTION OF REFRACTORY COATINGS IN A FOUNDRY
Wall Thickness of Piece,
|Solvent||Mould or Core Binder,
Health and Safety Rules,
|Flow System||Paint Application Method|
Advantages of Refractory Coatings:
- Prevents casting defects caused by sand
- Improves surface quality
- Prevents metal penetration and sand staining during the casting process
- Prevents veining defects caused by the interaction between sand and metal
- Ensures casting quality through prevention of impurities that have the possibility of contaminating the molten metal
- Minimizes thermal stress during solidification