Radial turbine rotor with additive layer manufactured components

Abstract

A multi-piece radial turbine rotor includes a hub and a bladed crown manufactured via additive layer manufacturing. A bond is formed between the hub and the bladed crown to fix the components together for rotation.

1 . A radial turbine rotor, the rotor comprising:
 a hub arranged around a central axis that defines a radially-innermost surface of the rotor, and   a crown having metallic layers deposited additively to provide a monolithic, single piece with a flowpath ring that extends annularly around the hub and a plurality of turbine blades that extend radially outwardly from the flowpath ring.   
     
     
         2 . The rotor of  claim 1 , wherein the crown is coupled to the hub via a metalurgical bond that fixes the crown to the hub for rotation therewith. 
     
     
         3 . The rotor of  claim 2 , wherein the metalurgical bond layer is a diffusion bond joint. 
     
     
         4 . The rotor of  claim 1 , wherein at least one of the plurality of turbine blades is formed to include a cooling air passageway therein. 
     
     
         5 . The rotor of  claim 4 , wherein complex cooling features including pins and fins are formed within the cooling air passageway. 
     
     
         6 . The rotor of  claim 4 , wherein the flowpath ring is formed to include at least one cooling air feed channel that opens radially inwardly to face the central axis. 
     
     
         7 . The rotor of  claim 6 , wherein the at least one cooling air feed channel is in fluid communication with the cooling air passageway formed in at least one of the plurality of turbine blades. 
     
     
         8 . The rotor of  claim 7 , wherein an axial end of the at least one cooling air feed channel is open to receive cooling air at a location radially inward of the plurality of turbine blades. 
     
     
         9 . The rotor of  claim 1 , wherein the crown comprises nickel superalloy materials. 
     
     
         10 . The rotor of  claim 9 , wherein the hub comprises nickel superalloy materials. 
     
     
         11 . A method of making a radial turbine rotor, the method comprising:
 forging a hub arranged around a central axis,   forming a crown with a flowpath ring that extends annularly around the hub and a plurality of turbine blades that extend radially outwardly from the flowpath ring via additive layer manufacturing so as to provide a monolithic, single piece component, and   coupling the crown to the hub by forming a joint radially between a radially inwardly facing surface of the crown and a radially outwardly facing surface of the hub.   
     
     
         12 . The method of  claim 11 , wherein the joint is a diffusion bond layer. 
     
     
         13 . The method of  claim 12 , wherein the hub and the crown are shrink fit together by sufficiently heating the crown and cooling the hub, resulting in thermal expansion of the crown to enable insertion of the hub into the crown. 
     
     
         14 . The method of  claim 13 , wherein after the hub is inserted into the crown, the assembly is heated in a vacuum furnace to a sufficient temperature to complete diffusion bonding. 
     
     
         15 . The method of  claim 11 , wherein the crown comprises nickel superalloy materials. 
     
     
         16 . The method of  claim 15 , wherein the hub comprises nickel superalloy materials.