Shell mould casting is one technology of casting. Products are casted from thin cast shells directly. Materials include carbon steel, alloy steel, etc. can all be casted in shell mould casting process.
Process for such shell mould casting includes,
*Step 1, Putting the easy-hardening sands(phenol-formaldehyde resin coated sand) on metal template with temperature 180-280℃, to achieve a hardend layer about 6-12mm thick.
*Step 2, Then keeping the hardend sands in constant temperature to solidify the sand layer. This will achieve enough strength and stiffness.
*Step 3, Clamping the up and down sand shells or sticking them with resin
*Step 4, Heat treating the sand shells to around 300℃
*Step 5, melting the steels and casting.
*Step 6, Opening the shells and cleaning the sands left on surface of castings.
Advantages for shell mould casting,
*Reducing amount of sands during casting process
*The outline of castings made by shell mould casting are more clear
*Surfaces of castings made by shell mould casting are much smooth
*Sizes of castings made by shell mould casting are much more accurate. This will save machining costs a lot.
Thus, Shell mould casting can be used for casting products with big quantity, high accuracy requirements, thin wall thickness and complexe in structure.
But costs of resin used in shell mould casting process are much higher. The metal template are required to be CNC machined. During shell mould casting,there will be stimulating smell left. All these factors prevent the steps for widely application of the shell mould casting. But resin sand shell mould casting can be used together with green sand casting,resin sand casting and other sand casting processes to cast products.
If you have requirements for shell mould casting, pls feel free to contact us.