Efficient Method and Materials for Ceramic Shell Casting
The WiSys Technology Foundation is seeking commercial partners interested in developing a novel investment casting process that can create a casting shell in as little as one coat.
Patent Issued Date: October 31, 2006
Stage of Development:
Ready for Commercialization
Investment casting is commonly used to produce high quality metal objects possessing extremely fine detail. Investment casting typically involves creating a thin-walled ceramic shell, or mold, around a pattern of a part; melting or otherwise removing the pattern once the ceramic shell has hardened; filling the ceramic shell with molten metal and letting the metal solidify; and finally conditioning the metal part to finish it.
In this casting process, the step of making the ceramic casting shell is particularly time-consuming. Creation of the shell involves dipping the part's pattern into a slurry of liquid refractory material, and then, while the coat is still wet, sieving dry refractory grains (e.g., silica) onto the pattern. After the coat air-dries, dipping and sieving are repeated as many as seven times to produce the desired, thin-walled shell.
A Wisconsin researcher has developed a novel colloidal refractory material and method for investment casting that can create a casting shell in as little as one coat. In addition, this process produces a casting shell that retains more heat and hardens faster than traditional investment casting shells.
All types of metal casting, as well as casting of other materials
-Produces a casting shell in as little as one coat, dramatically reducing the equipment needed for process automation
-Reduces four-fold the time needed to make a casting shell (from 24 to six hours), saving significant labor and expense
-Eliminates the need to apply dry refractory grains, which can pose a health hazard
-Shell's improved ability to retain heat allows pouring of molten metal at lower temperature, providing dramatic energy savings
-Requires less material than conventional methods, and material is 100 percent reusable
-Provides a stable slurry that requires no mixing, unlike conventional slurries
-Slurry can be applied in many ways, including brushing, spraying, dipping, pouring and packing
-Fully compatible with current robotic application technologies