Cooled Composite Mold for Turbine Blade Casting Technology Description Increasing the high temperature mechanical properties of turbine blades reduces the need for cooling and improves turbine engine efficiency. Heat extraction from the mold is critical in casting good blades, but conventional directional solidification furnaces typically rely on radiative cooling augmented by isolated "chill plates" at discrete locations, which limits the precision of local temperature control. This project investigated a concept for improved heat extraction through the use of composite molds having enhance through-thickness thermal conduction and an innovative means of actively cooling the mold near the solidification front without physical translation of either the mold or the furnace. Potential Benefits The use of enhanced-conductivity composite molds should provide greater temperature control with steeper gradients and reduced jitter for higher temperature turbine blade castings and a lower reject rate. Development Status ESLI performed a Phase 1 SBIR contract with the U.S. Air Force to develop enhanced-conductivity composite molds for turbine blade casting. Phase 1 investigated the materials and cooling concept at temperatures up to 3100 degrees F (1700 Degrees C). Full-scale composite molds were fabricated and used in casting of eutectic metal crystals to assess the feasibility of improved casting of superalloy turbine blades. Phase 2 plans include the development of prototype molds with integrated cooling for use in solidification of single-crystal turbine blades.
U.S. Air Force Phase 1 SBIR (F33615-97-C-2734) |
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