Investment Cast, often referred to as Lost Wax Casting, is considered a Precision Casting process to produce near-net-shapes from most alloys. The process starts with machining a metal split mold of the part in negative form. Then special investment wax is injected into the mold. The cooled injected waxes are then mounted to a wax tree that is a sprue, gate and runner system. The entire tree is then dipped many times into a ceramic slurry to achieve a 6-8mm shell, and finally covered with a sand stucco and dried.
Once dried, the entire assembly is placed into an autoclave to remove most of the wax. After autoclaving, the remaining wax that soaked into the shell is burned out in a furnace. What remains is a hollow negative of the part. After preheating the shell assembly, molten metal is poured thru the sprue and runner system filling the cavities to form positive parts. Once cooled, the shell mold is then chipped away from the casting, the gates and runners cut off and the parts are cleaned by abrasive belt, hand tooled and finally abrasive blasted.
