* Click on the image to enlarge.
There are many ways for starting of the casting process may be
expressed, but the most common way of starting this procedure to supply us your
drawings and detailed specification of your product. Once we get these drawings we get in touch with customers design engineer and build an
aluminium die with
internal cavities that will produce a wax sample by injecting wax into the die.
We send these wax patterns to customer and after approval of wax patterns we
make sample casting. The wax patterns are attached to an assembly made from wax
(called cluster/tree) that allows molten metal to enter, that produces a sound
metal component.
The cluster is rinsed in a pattern wash/etching solution. The
cluster is then dipped into controlled ceramic slurry. The cluster is drained
and coated with a ceramic media that begins with a fine powder like substance
on the first coat. Subsequent coats are put on the cluster called secondary or
backup coats. The secondary/back up coating process is repeated as necessary
until the shell is strong enough to hold molten metal. After the ceramic dries,
the wax is removed (called De-Waxing process). The wax will be recycled for use
in future wax pattern assembly production. These ceramic shells provide an
accurate copy of the wax patterns that will be used for producing metal
components.
The ceramic shell moulds are fired in ovens to burn out last
traces of pattern material and in order to achieve maximum strength, then
removed and placed on sand beds. By that time based on the specifications
provided by the customer, metal is melted in the furnaces using certified
material and then verified using spectrometer to insure that the metal
chemistry meets the specifications. This ceramic shell is filled with the
molten metal.
After the molten has cooled, the shell material is removed from
the casting cluster using vibratory or shot blast methods. The castings are
removed from the cluster by cutting gates. Remaining parts of gates are then
removed by grinding and then using shot or sand blasting, finished components
are achieved.
Post
Processing
Heat
Treatment
Blasting (Sand
and Shot)
Knock
Out
Straightening
|
Machining
Drilling
Tapping
Milling
Boring
Turning
|
Final
Finishes
Polishing
Hand
Buffing
Degreasing
Corrosion-resistant Coatings
Anodizing
Electro Plating
Black Oxide
Pickling
Assembly
|
Advantages of Investment Casting
investment casting can be applied to produce parts of varying degrees complexity, in virtually any volume and for the broadest possible spectrum of applications.
Allows very rapid prototype development
Allows greater design freedom for very simple to highly complex parts
Can utilize a wide variety of alloys
Yields lighter, stronger metal parts with superior finishes
Provides superior repeatability
Reduces labor, tooling and machining costs
Close Dimensional Tolerances
Sales appeal is enhanced by improved performance
85% or more of the final shape is available in the investment casting.
Physical properties remains same in each dimensions.
Design changes at costs far less than those of other techniques
Requires little or no draft in tooling
|
|