What is Investment Casting Process

OTTOMMO Casting continues to improving our investment casting process and utilizing the newest technology available in our industry.

Wax Injection Investment Casting Process

Operators inject wax into aluminum mold/tooling to produce a wax pattern of the part. The design and condition of the mold/tooling is critical. Our extensive engineering experience on mold/tooling design will make it easy for you. Especially, there is a big difference between China and other countries for mold/tooling concept.

Soluble Wax Core and Wax Cleaning

OTTOMMO Casting makes soluble wax core available to you and this service is very rare in China. Basically, the soluble core will place inside the wax pattern tool. Operators will inject the pattern wax around the soluble to produce the desired interior and exterior geometry. Any imperfections will be evident in the metal part if operators do not repair the wax. Therefore, double checking and wax cleaning is very necessary to avoid the casting defects.

Wax Assembly Investment Casting Process

Operators assemble wax patterns on to wax tree to produce a complete wax mold. The wax tree design is very critical. This is how the metal will ultimately distribute into the mold and feed the casting. OTTOMMO Casting utilizes the solidification software to simulate process of pouring metal. As a result, we will get a better idea of where to put the gates and how many wax patterns should be on the tree.

Dip and Shell Investment Casting Process

Operators will load trees on to the dip room conveyor and queue to begin the dip and shell process. Normally, operator will do the first wax dip into a slurry. Then, they will dip the tree into either water glass quartz sand or silica sand silica sol zircon sand.

Ceramic Drying Process

Every part is different for the complexity of the geometries. Hence, specific dry times for the various dip coats are different. The dipping process will repeat an average of 7-8 times over several days. This will make sure there is a sufficient ceramic shell around the wax mold.

Dewax Investment Casting Process

Operator will put the ceramic shell with the wax mold inside into the flash fire. This will remove the wax and empty the ceramic shell. Most Chinese foundries will reclaim the wax and use for the future wax injection process. OTTOMMO Casting has never done this. We will reclaim the wax back to the wax company and get the discount for the new wax from them.

Mold Preheat and Pouring Process

Operator will melt the alloy to its specific pouring temperature. In the meantime, they will preheat the ceramic shell to desired temperature. In this way, the ceramic shell will not crack because of the temperature difference between metal and shell. Once the metal and shells have reached the required temperature, operator will pour the metal into the hot mold.

Shell Removal Investment Casting Process

Operator will let the shells filled with metal cool off to room temperature. Then they will remove the ceramic shell by our shot blast machine. Besides, any remaining ceramic they will do manual sandblasting. After this, operator will cut off the parts from the metal tree and grind the remaining gate. Eventually, we will do casting inspection and ship parts to our customers.