Shell Mould Casting

The metal pattern is first heated at a temperature of 200 0 C / 392 0 F.Then covered with a mixture of sand and thermo set plastic. It forms a skin of sand/ plastic mixture of about 3.5 mm (0.125 inch) which adheres to the pattern. The shell mold is formed after the skin gets removed from the pattern. The two halved of the shell mold are secured together and the metals id poured in the shell to form the part. Once the metals solidified, the shell is broken.

Features of Shell mold Casting:


* Good Surface Finish : 1.25Aum to3.75Aum (50Auin to 150Auin)rms dimensional Tolerance of 0.5 %
* Size Limits : 30 g to 12 kg (1 oz to 25lb)
* Minimum Thicknesses : As low as 1.5mm (0.062 in) to 6.25mm (0.25 in)depending on the material
* Superior Machining Qualities : As it has soft skins and hard or dense interiors
* Draft Allowance : Typically 10 C


Application:

The materials that can be used with this process are aluminum, cast irons, and copper alloys. Parts made can be connecting rods, Gear Housings, Lever arms etc.