How To Remove Ceramic Cores

Magnus engineered equipment mee has supplied equipment to the investment casting industry for more than 50 years.

How to remove ceramic cores.

Investment casting or die casting is a technique for forming metallic components having complex geometries especially hollow components. These cores are predominantly found in aerospace and industrial markets but there is a growing demand in the healthcare sports and automotive markets. To destructively remove a casting core from a cast part the part is exposed to a combination of nitric acid and sulfuric acid. In the investment casting industry ceramic cores have played an important part in the development of improved performance of blades and vanes in gas turbines.

Following firing the ceramic core may undergo additional processes to improve its performance at the time of investment casting process. In the investment casting process or lost wax a shell is created to provide a mold for the parts. A method of removing ceramic material such as for example a ceramic core from a metallic cast or other component involves contacting the metallic cast component and a caustic ceramic leaching medium at elevated temperature for a time effective to substantially remove the ceramic material from the component and providing an oxygen getter in the caustic ceramic leaching medium in an amount. These processes include impregnation of the core to enhance its stability at room or high temperatures.

Sand core and shell investment casting removal using caustic leaching. A method of removing ceramic material such as for example a ceramic core from a metallic cast or other component involves contacting the metallic cast component and a caustic ceramic leaching medium at elevated temperature for a time effective to substantially remove the ceramic material from the component and providing an oxygen getter in the caustic ceramic leaching medium in an amount. The combination may be an aqueous solution including by volume 40 60 nitric acid and 3 10 sulfuric acid. The combination may have by volume a nitric acid concentration of 4 20 times the sulfuric acid concentration.

Shell removal for foundries. Ceramic cores have been used in castings for many years to assist in achieving ever more complex internal geometry.