Investment casting derives its name from pattern surrounded by refractory materials. Many materials are suitable for investment casting for example :- S.S, M.S, BRASS etc. the materials are poured into a cavity in refractory material that to exact desired part.
The process can be more expensive than die casting or sand casting, but pre unit casts decreases with large volume. Investment casting can produce complicated shapes that would be difficult or impossible with other casting methods.
Designing the tool as per the component’s geometry and quantity requirements considering various factors like shrinkage properties of wax or metal.
Firstly the replica of the required casting is produced with the help of injection molding, such pattern is called wax pattern.
Further, wax pattern goes for cleaning and repairing through which any dust particles are taken of and repairing is done wherever is required by the repairing wax.
After cleaning and repairing of wax pattern further goes for assembly where the shell is gets built with the wax pattern and making a tree of a wax pattern with the spure.
Thirdly, a shell of wax pattern is made by dipping into a container of liquid ceramic slurry followed by putting it into very fine sand which approximately 6 to 8 layers are applied according to geometry of shell.
Fourthly the shell is placed into de-waxing where the wax inside the shell is immediately gets melted out by heating, the moment the ceramic cluster is dried out, which creates the cavity inside the shell.
After de-waxing the shell is put into the shell baking furnance for pre heating it.
After pre heating the shell , molten metal is poured into the shell via gravity pouring. When pored metal cools down cups, sprue, gates and components turns into solid cavity.
When metal cools down and turns solid, the shell gets vibrated which knockout the ceramic slurry from the shell.
The parts are burn cut away from sprue and get reporated with the help of cutting machine.
After cutting of parts, fetling work takes place such as grinding of parts, finishing and total ceramic coating is removed by blasting and chemical process done on inside and outside surface.
After complete finishing of casting further it goes for visual and dimensional casting.