Ceramic cores for investment casting

Ceramic cores are used to produce Intricate Internal Shapes in production of Investment Castings.With the help of Ceramic Cores,critical castings applicated in Power Generation,Automobile,Transmission and other industries can be done in Investment Casting. 

These are two different types of Ceramic Cores, One produced by Injected Ceramic Cores and the other is chemically Gelled Ceramic Cores . 

We have developed Injected Ceramic Cores for Investment Casting process and other applications. Presently we are offering Finished Ceramic Cores, ready to use Refractory Mix for Injected Ceramic Cores and the Technology for producing Injected Ceramic Cores. 

Here we are briefly introducing the Ceramic Core production process and the basic comparison between the two types of the ceramic cores.

A.Injected Ceramic cores

The production steps of the injected Ceramic Core are as follow:

1.Injecting the refractory mix bled into the core cavity after solidification the green core is removed from the cavity.
2.After inspecting the core it is packed in the ceramic flour and sintered in the furnace.
3.After sintering of the core it is used in the wax pattern production.

The main advantages of the injected ceramic cores:

*As the refractory mix is blended in the bulk qualities and then it is used for the injection of ceramic cores. The consistency of the ceramic cores is reliable whereas in case of gelling ceramic core,for production of individual ceramic core the refractory mix is measured and mixed with the binder. This could be affecting the variation, resulting in inconsistency.
*The surface finish and physical properties of the Injected Core quality is better than any other types of cores.
*While backing of the gelled ceramic cores due to the stress release, there are chances of bending, elongation and surface cracks. As the injected cores are packed in ceramic materials the chances of bending and cracking are eliminated.
*Incase of gelling ceramic cores the gel time must be maintained very accurately. If the pouring takes more time then the gelling time, the gelling of the mix take place before pouring and this results in wasting the refractory and binder material. And if the pouring is done much earlier than the gelling time, the solid particles settle down in the cavity resulting in the uneven properties. While in case of injected ceramic cores rejected green cores risers and getting can be also reused. Injecting this material in the cavity is as easy as injecting a pattern wax.
*The shelf life of the refractory mix is as good as a Pattern Wax. Where as in case of gelling binder material have a very limited shelf life.

B.Chemically Gelled Ceramic Cores

The production steps of chemically gelled ceramic core are as follow:

1.Refractory mix of the known quantity is mixed with the liquid binder, for each single core to be produced.
2.After mixing the binder with the refractory mix, a gelling solution is added while continues stirring.
3.After the pre calculated gel time the mix is poured in the core cavity and after setting of the core it is removed from the cavity and fired.
4.The fired ceramic core after finishing is used in a die cavity to inject the wax pattern.

Disadvantages of Chemically Gelled Ceramic Cores:

*High wastage and rejection percentage.
*No suitable for mass production.
*Low consistency.
*Low hardness and strength,could not withstand the Wax Injection pressers when using the cores for wax pattern production.