METHOD FOR MAKING A TURBINE AIRFOIL
A method of making a turbine airfoil includes generating an airfoil core ( 14 ) that includes a core exit along an extended portion ( 28 ) of the trailing edge ( 32 ) outside of the airfoil part geometry. Float points ( 12 ) are positioned along the extended portion ( 28 ) of the airfoil core ( 14 ). Each float point ( 12 ) includes a float feature ( 34 ) that includes a localized radially straight surface ( 42 ) extending out and creating a gap ( 18 ) between the airfoil core ( 14 ) and the mold shell ( 16 ).
1 . A method for making a turbine airfoil, comprising:
generating a mold shell ( 16 );
generating an airfoil core ( 14 ) comprising a pressure side ( 38 ) and suction side ( 40 ) that are connected by the trailing edge ( 32 ) and a leading edge ( 30 ), a radially outward tip end ( 22 ) and a radially inward root end ( 20 ), and a core exit along an extended portion ( 28 ) of the trailing edge ( 32 ) outside of the airfoil part geometry; and
positioning float points ( 12 ) along the extended portion ( 28 ) of the airfoil core ( 14 ), wherein each float point ( 12 ) includes a float feature ( 34 ) that includes a localized radially straight surface ( 42 ) extending out and creating a gap ( 18 ) between the airfoil core ( 14 ) and the mold shell ( 16 ).
2 . The method of claim 1 , wherein the floats ( 12 ) are along both the pressure side ( 38 ) and suction side ( 40 ) of the airfoil core trailing edge extended portion ( 28 ).
3 . The method of claim 1 , wherein the floats ( 12 ) are along one of the pressure side ( 38 ) or suction side ( 40 ) of the airfoil core trailing edge extended portion ( 28 ).
4 . The method of claim 1 , wherein the airfoil core ( 14 ) includes a curved trailing edge ( 32 ) in a radial direction (R).
5 . A method for making a turbine airfoil, comprising:
generating a mold shell ( 16 );
generating an airfoil core ( 14 ) comprising a pressure side ( 38 ) and suction side ( 40 ) that are connected by the trailing edge ( 32 ) and a leading edge ( 30 ), a radially outward tip end ( 22 ) and a radially inward root end ( 20 ), and a core exit along an extended portion ( 28 ) of the trailing edge ( 32 ) outside of the airfoil part geometry;
positioning float points ( 12 ) along the extended portion ( 28 ) of the airfoil core ( 14 ), wherein each float point ( 12 ) includes a float feature ( 34 ) that includes localized radially straight surface ( 42 ) extending out and creating a gap ( 18 ) between the airfoil core ( 14 ) and the mold shell ( 16 );
introducing molten metal alloy into the gap and surrounding the floats points;
solidifying the alloy to form an airfoil casting having a plurality of float point openings ( 44 ) at the extended portion ( 28 ) location;
removing the mold shell ( 16 ) so as to expose the airfoil ( 46 ); and
sealing the plurality of float point openings ( 44 ) in the airfoil ( 46 ).
6 . The method of claim 5 , wherein the floats ( 12 ) are along both the pressure side ( 38 ) and suction side ( 40 ) of the airfoil core trailing edge extended portion ( 28 ).
7 . The method of claim 5 , wherein the floats ( 12 ) are along one of the pressure side ( 38 ) or suction side ( 40 ) of the airfoil core trailing edge extended portion ( 28 ).
8 . The method of claim 5 , wherein the airfoil core ( 14 ) includes a curved trailing edge ( 32 ) in a radial direction (R).