Abstract: A method of creating an article from investment casting includes forming a ceramic seed well, heating the ceramic seed well to form a hardened ceramic seed well, attaching a meltable pattern to the hardened ceramic seed well, coating the hardened ceramic seed well and the meltable pattern with hardenable ceramic material, heating the hardenable ceramic material to melt the meltable pattern, removing the meltable pattern from the hardenable ceramic material, firing the hardenable ceramic material to form a ceramic mold having a cavity, placing a seed within the hardened ceramic seed well, and pouring molten metal into the hardened ceramic seed well and the cavity. The cavity of the ceramic mold is in communication with the hardened ceramic seed well.

Abstract: In the castings of a turbine element, a sheet casting core is assembled to a feedcore. The sheet casting core and feedcore are placed in a die. A sacrificial pattern material is molded over the casting core and feedcore to form a pattern including an airfoil. The sheet casting core extends from at or adjacent a trailing edge of the airfoil. The sheet casting core has a first array of open areas and a second array of portions interspersed with the open areas. A first portion of the die has a third array of projections contacting the second array.

Abstract: A method of forming a gating fixture for a lost wax casting process includes determining an optimal orientation of a gate in relation to a part, and forming a fixture that can repeatably be used to consistently locate the gate relative to the part. In one example, stereolithography is used to form the fixture.

Abstract: In an investment casting process, a composite core is formed as a combination of ceramic casting core element and a non-ceramic casting core element. The core is heated in an oxidative atmosphere and then heated in a non-oxidative atmosphere.

Abstract: A method of forming a gating fixture for a lost wax casting process includes determining an optimal orientation of a gate in relation to a part, and forming a fixture that can repeatably be used to consistently locate the gate relative to the part. In one example, stereolithography is used to form the fixture.

Abstract: In the castings of a turbine element, a sheet casting core is assembled to a feedcore. The sheet casting core and feedcore are placed in a die. A sacrificial pattern material is molded over the casting core and feedcore to form a pattern including an airfoil. The sheet casting core extends from at or adjacent a trailing edge of the airfoil. The sheet casting core has a first array of open areas and a second array of portions interspersed with the open areas. A first portion of the die has a third array of projections contacting the second array.

Abstract: An apparatus for shelling an investment casting pattern has a tank containing a coating material. There are means for holding the pattern immersed in the coating material. There may be means for vibrating the pattern during immersion of the pattern and a vacuum source coupled to the tank to withdraw air from at least one headspace of the tank.

Abstract: An apparatus for shelling an investment casting pattern has a tank containing a coating material. There are means for holding the pattern immersed in the coating material. There may be means for vibrating the pattern during immersion of the pattern and a vacuum source coupled to the tank to withdraw air from at least one headspace of the tank.

Abstract: An at least two step heating process is used to strengthen the shell of an investment casting mold including a refractory metal core. The first stage may occur under otherwise oxidizing conditions at a low enough temperature to avoid substantial core oxidation. The second stage may occur under essentially non-oxidizing conditions at a higher temperature.