Bicast turbine engine components

Abstract

A turbine blade assembly includes a turbine blade having a pressure sidewall and an opposed suction sidewall and a first snubber assembly associated with one of the pressure sidewall and the suction sidewall. The first snubber assembly includes a first base portion extending outwardly from the one of the pressure sidewall and the suction sidewall, and a first snubber portion. The first base portion is integrally cast with the turbine blade and includes first connection structure. The first snubber portion is bicast onto the first base portion and includes second connection structure that interacts with the first connection structure to substantially prevent separational movement between the first base portion and the first snubber portion.

What is claimed is: 
     
         1 . A turbine blade assembly in a turbine engine comprising:
 a turbine blade having a pressure sidewall and an opposed suction sidewall; and   a first snubber assembly associated with one of the pressure sidewall and the suction sidewall and comprising:
 a first base portion extending outwardly from the one of the pressure sidewall and the suction sidewall, the first base portion being integrally cast with the turbine blade and including first connection structure; and 
 a first snubber portion bicast onto the first base portion and having second connection structure that interacts with the first connection structure to substantially prevent separational movement between the first base portion and the first snubber portion. 
   
     
     
         2 . The turbine blade assembly of  claim 1 , wherein the first connection structure comprises one of an annular ridge and an annular groove and the second connection structure comprises the other of an annular ridge and an annular groove. 
     
     
         3 . The turbine blade assembly of  claim 1 , wherein the first base portion and the first snubber portion have substantially equivalent outer diameters at a junction therebetween such that there is substantially no discontinuity of the first snubber assembly at the junction. 
     
     
         4 . The turbine blade assembly of  claim 1 , wherein the outer diameter of the first snubber portion decreases as the first snubber portion extends away from the turbine blade. 
     
     
         5 . The turbine blade assembly of  claim 1 , wherein separational movement between the first base portion and the first snubber portion is substantially prevented by the first and second connection structures without a bonding material. 
     
     
         6 . The turbine blade assembly of  claim 1 , wherein the first base portion includes an opening formed therein in communication with a cooling passage within the turbine blade, the opening receiving cooling fluid from the cooling passage. 
     
     
         7 . The turbine blade assembly of  claim 6 , wherein the first snubber portion includes a cooling passageway in communication with the opening in the first base portion, the cooling passageway receiving cooling fluid from the opening. 
     
     
         8 . The turbine blade assembly of  claim 7 , wherein the first snubber portion includes at least one cooling fluid outlet that discharges cooling fluid in the cooling passageway from the first snubber assembly. 
     
     
         9 . The turbine blade assembly of  claim 1 , further comprising:
 a second snubber assembly associated with the other of the pressure sidewall and the suction sidewall and comprising:
 a second base portion extending outwardly from the other of the pressure sidewall and the suction sidewall, the second base portion being integrally cast with the turbine blade and including third connection structure; and 
 a second snubber portion bicast onto the second base portion and having fourth connection structure that interacts with the third connection structure to substantially prevent separational movement between the second base portion and the second snubber portion. 
   
     
     
         10 . A coupling between two components in a turbine engine comprising:
 a first component formed by a first casting procedure and including first connection structure comprising one of a continuous annular ridge and a continuous annular groove; and   a second component bicast onto the first component during a second casting procedure and having second connection structure comprising the other of a continuous annular ridge and a continuous annular groove, the second connection structure interacting with the first connection structure to substantially prevent separational movement between the first component and the second component.   
     
     
         11 . The coupling of  claim 10 , wherein the first component and the second component have substantially equivalent outer diameters at a junction therebetween such that there is substantially no discontinuity between the first and second components at the junction. 
     
     
         12 . The coupling of  claim 10 , wherein separational movement between the first component and the second component is substantially prevented by the first and second connection structures without a bonding material. 
     
     
         13 . A method for forming a turbine blade assembly comprising:
 performing a first casting procedure to form:
 a turbine blade having a pressure sidewall and an opposed suction sidewall; and 
 a base portion of a snubber assembly, the base portion extending from one of the pressure sidewall and the suction sidewall; 
   performing a second casting procedure comprising:
 casting a snubber portion onto the base portion such that first connection structure of the base portion interacts with second connection structure of the snubber portion to substantially prevent separational movement between the base portion and the snubber portion. 
   
     
     
         14 . The method of  claim 13 , wherein:
 the first connection structure is machined into the base portion after the first casting procedure and comprises one of an annular ridge and an annular groove; and   the second connection structure comprises the other of an annular ridge and an annular groove.   
     
     
         15 . The method of  claim 13 , wherein the base portion and the snubber portion are cast to have substantially equivalent outer diameters at a junction therebetween such that there is substantially no discontinuity of the snubber assembly at the junction. 
     
     
         16 . The method of  claim 13 , wherein separational movement between the base portion and the snubber portion is substantially prevented by the first and second connection structures without a bonding material. 
     
     
         17 . The method of  claim 13 , wherein the base portion is cast to include an opening in communication with a cooling passage cast within the turbine blade, the opening for receiving cooling fluid from the cooling passage during operation of an engine including the turbine blade assembly. 
     
     
         18 . The method of  claim 17 , wherein the snubber portion is cast to include a cooling passageway in communication with the opening in the base portion, the cooling passageway for receiving cooling fluid from the opening during operation of the engine. 
     
     
         19 . The method of  claim 18 , further comprising forming at least one cooling fluid outlet in the snubber portion, the at least one cooling fluid outlet for discharging cooling fluid in the cooling passageway from the snubber assembly during operation of the engine.