(Last Updated January 17, 2020)
Investment casting, similar to Lost-Wax casting, is thousands of years old. Documented for the first time around 1100 A.D.by a monk named Theophilus Presbyter, the term “investment” refers to the mold being filled or invested with metal. Investment casting was originally used to produce decor, religious statues, and jewelry. This casting process eventually made its way to the industrial revolution and became a favorite method of Dentists for creating crowns and inlays. Investment casting is still used today to produce intricate castings with brilliant, smooth finishes.
Investment casting is a method of casting in which a mold is created, commonly using wax (though some use plastics), utilizing a gating system that works in branches, allowing flow between the different compartments. This result of the tree-like system is that multiple castings can be created all at once, from a single mold. Once created, the wax mold is coated in a ceramic shell or “refractory mold” that will keep the shape of the mold when the wax is melted out in an oven. Usually selected from stainless-steel alloys, brass, aluminum, or carbon steel, the molten metal of choice is then poured into the refractory mold to create the casting. The metal will harden and solidify in the shape created by the mold, and leave a perfectly-matched final product when the ceramic shell is broken and removed. Investment casting is a favorite choice for those looking to create an intricate end product or part due to the completely enclosed pattern. Investment casting can capture details that other forms of casting, like sand casting, cannot always accomplish.
As mentioned previously, investment casting is ideal for creating intricate patterns. Metal castings made using the investment process can be made very thin and with great accuracy. The hard molds of investment casting also allow for a smoother surface to the final product. However, there is a negative aspect to investment casting: though the wax can easily be reused time and time again, the ceramic shell, once used, is lost. This makes the process more complicated and more expensive. Although some of the investment casting process can be automated, much of the procedure still needs to be executed manually. But, once the process is complete, investment casting products do not need any secondary processing to be ready for use.
General Kinematics is a great investment for any casting process or pattern. With over half a century of experience and a track record for reliability, GK can improve the performance of your metal casting process. Ask a GK Engineer how we can automate your work-flow today, check out our metal casting equipment, or read the stories of others in the metal casting industry that have used (and loved!) GK equipment to improve their process.