Our in house tool maker produces an aluminium die from customer drawings.
A wax mould of the component to be cast is produced by injecting high-technology wax into the aluminium die.
A number of wax components are then mounted on to a wax runner. Each runner may contain one large component or numerous small components.
The whole wax assembly is then dipped (or invested) into a water based binder and receives a Primary Coat of fine silica sand. This fine material is used first to give a smooth refractory surface finish and reproduce fine details. The coated assembly is then dried in a temperature controlled environment.
The Primary Coated assembly is then dipped into a water based binder and is coated with ceramic particles. This is then dried in a temperature controlled environment. Further layers are added and dried until the mould (investment) is the required thickness.
Once completely dried the mould is placed in a steam autoclave to melt out the wax; the process is sometimes called the lost wax process. Now just the ceramic shell remains.
The ceramic shell is then fired at approx 1000° C to remove any moisture and residual wax and to cure the shell. The shell is now a ceramic impression of the part to be cast.
Whilst the ceramic shell is hot, it is filled with molten metal, creating the metal casting.
Once the metal has cooled, the ceramic shell is removed leaving a casting that requires little or no finishing.
Next the castings are cut away from the runner and any necessary final post-processing (sandblasting, polishing, machining) is done to finish the casting.