Method for removing refractory metal cores

1. A furnace for removing a molybdenum-alloy refractory metal core through sublimation comprising:

a retort furnace having an interior;

a sublimation fixture insertable within said interior of the retort furnace, said sublimation fixture configured to receive at least one turbine blade having the molybdenum-alloy refractory metal core;

a flow passage thermally coupled to said retort furnace configured to heat a fluid flowing through said flow passage and deliver said fluid to said molybdenum-alloy refractory metal core causing sublimation of said molybdenum-alloy refractory metal core, wherein said flow passage is fluidly coupled to a coupling configured to receive air, and said flow passage is fluidly coupled to a junction at an end opposite said coupling, said junction being configured to fluidly couple to said sublimation fixture.

2. The furnace for removing a molybdenum-alloy refractory metal core through sublimation according to claim 1 , wherein said flow passage is formed within a wall of the retort furnace.

3. The furnace for removing a molybdenum-alloy refractory metal core through sublimation according to claim 1 , wherein said sublimation fixture comprises a blade receiver fluidly coupled to said flow passage, said blade receiver configured to receive a root of said turbine blade.

4. The furnace for removing a molybdenum-alloy refractory metal core through sublimation according to claim 1 , further comprising:

a collector fluidly coupled to said interior of the retort furnace, wherein said collector is configured to collect waste discharged from the blade responsive to sublimation of said molybdenum-alloy refractory metal core.

5. The furnace for removing a molybdenum-alloy refractory metal core through sublimation according to claim 1 , further comprising:

an inner furnace box within an outer furnace box of said retort furnace, said inner furnace box configured to receive said sublimation fixture.

6. The furnace for removing a molybdenum-alloy refractory metal core through sublimation according to claim 1 , wherein said inner furnace box comprises an enclosure coupled to a base at a joint having a seal between a wall of said enclosure and said base.

7. A furnace for removing a molybdenum-alloy refractory metal core from a blade through sublimation comprising:

a retort furnace comprising an outer furnace box having an interior;

an inner furnace box within said interior, said inner furnace box comprising an enclosure coupled to a base;

a sublimation fixture insertable within said inner furnace box, said sublimation fixture configured to receive at least one turbine blade having the molybdenum-alloy refractory metal core;

a flow passage coupled to said sublimation fixture; said flow passage thermally coupled to said retort furnace configured to heat a fluid flowing through said flow passage and deliver said fluid to said molybdenum-alloy refractory metal core causing sublimation of said molybdenum-alloy refractory metal core, wherein said flow passage is fluidly coupled to a coupling configured to receive air, and said flow passage is fluidly coupled to a junction at an end opposite said coupling, said junction being configured to fluidly couple to said sublimation fixture; and

a collector fluidly coupled to said interior of the outer furnace box, wherein said collector is configured to collect waste discharged from the blade responsive to sublimation of said molybdenum-alloy refractory metal core.

8. The furnace for removing a molybdenum-alloy refractory metal core through sublimation according to claim 7 , wherein said flow passage is formed within a wall of the inner furnace box.

9. The furnace for removing a molybdenum-alloy refractory metal core through sublimation according to claim 7 , wherein said sublimation fixture comprises a blade receiver fluidly coupled to said flow passage, said blade receiver configured to receive a root of said turbine blade.

10. The furnace for removing a molybdenum-alloy refractory metal core through sublimation according to claim 7 , wherein said enclosure is coupled to the base at a joint having a seal between a wall of said enclosure and said base.

11. The furnace for removing a molybdenum-alloy refractory metal core through sublimation according to claim 7 , wherein said sublimation fixture comprises a cavity formed between internal plenums opposite said blade receiver.