Investment casting from jiachuan's blog

Investment casting is an option for manufacturing complex parts and assemblies. There are several specific steps throughout the process to design and create the required artifacts. It is so named because the workpiece is built around a shelled casting that is removed once the workpiece is poured into the mold and set in place. The investment casting process can refer to the following steps.

Step 1: Create the stencil/pattern

The first step in the process is to create a mold or pattern of the desired workpiece. The pattern is made of wax. It can be poured into a mold using injection molding, hand sculpted with a block of wax, or printed using a 3D printer and the appropriate wax material.

Step 2: Install the wax pattern

Investment casting tools involve creating multiple wax patterns and attaching them to a "door" device. The equipment is where metal or other materials are poured to eventually produce the desired workpiece.

Step 3: Tree Assembly

The tree assembly completes the installation of the wax model on the "door" unit. It's called a tree at this step because each individual wax pattern is essentially a "branch" that becomes a finished workpiece once the process is complete. You may have seen tree components in new board games that require pieces to be removed before use.

Step 4: Shell Molding

Once the tree is assembled, the next step is to add shell castings around it. First, dip the tree in a ceramic slurry. It is then dipped in fine sand plaster. Molded products must be completely dry before use. These two processes can be done multiple times until the mold is thick enough to handle the casting stresses.

Step 5: Wax removal

The wax mold must be removed before pouring the desired material into the newly shelled mold. This is usually done by heating the wax in an oven. Steam can also be used to heat the wax. Hold the mold upside down so that the liquid wax can flow out of it and reuse it to create new wax molds.

Another way to remove wax is to heat the wax so that it "burns" away and removes it completely from the shelled casting.

Step 6: Die Casting

After the wax is removed, the shelled casting will have an open space inside the formal wax mold shape. Pour molten metal or other liquid material into the casting. The material remains in the casting until it cools and solidifies completely.

Step 7: Remove Shell Casting

Use a hammer or other tool to remove the shelled casting until only the original tree remains. Instead of a wax mold, there will now be finished workpieces attached to the tree. After removing the casting, carefully cut the workpiece away from the tree.

Step 8: Finish the operation

Check each workpiece for defects. If any are found, they are discarded and the material recycled. The final step in the investment casting process is to apply different finishing methods to the workpiece. They can be sanded, coated, smoothed, machined, etc. to achieve the desired effect.

Metal parts produced by the lost wax process

Investment casting tools are ideal for high-volume or complex workpieces that require precise detail. The exact steps in the process can and do vary depending on the complexity of the artifact being created.

To learn more about investment casting and whether it is the best solution to manufacture the workpiece you need, contact Laszeray Technology, LLC at 440-582-8430 today!

We offer a wide range of services including product design, rapid prototyping, injection molding, investment casting, CNC machining, secondary and finishing operations, and more!