Shrouded wheel method of manufacture

Abstract

A method for manufacturing a turbomachine shrouded wheel involves separately moulding a first green, moulded part forming a hub and blades, and a second green, moulded part forming a shroud, using a feedstock comprising a metal powder and a binder. The green, moulded parts are adjoined in a mated configuration, with additional feedstock placed between respective connection-surfaces on the moulded parts. The adjoined moulded parts are sintered to fuse them into a single unitary, monolithic structure. The moulded parts' connection-surfaces form conforming protrusions and depressions, which have surface discontinuities spaced at intervals along their respective lengths.

What is claimed is: 
     
         1 . A method for manufacturing a turbomachine shrouded wheel, comprising:
 providing a first moulded part of the shrouded wheel, the first moulded part having one or more first-part connection-surfaces;   providing a second moulded part of the shrouded wheel, the second moulded part having one or more second-part connection-surfaces, wherein the one or more second-part connection-surfaces are shaped and sized to receive the first-part connection-surfaces fully and conformingly when the first moulded part and the second moulded part are positioned and adjoined to one another in a mated configuration;   positioning and adjoining the first moulded part and the second moulded part with respect to one another in the mated configuration such that the one or more second-part connection-surfaces fully and conformingly receive the first-part connection-surfaces; and   sinter-fusing the first-part connection-surfaces to the second-part connection-surfaces to form the turbomachine shrouded wheel.   
     
     
         2 . The method of  claim 1 , wherein:
 the first moulded part is a moulded wheel including a plurality of blades that form the one or more first-part connection-surfaces, the first-part connection-surfaces forming protrusions;   the second moulded part is a moulded shroud shaped to conformingly receive the moulded wheel; and   the moulded shroud forms the one or more second-part connection-surfaces, the second-part connection-surfaces forming depressions shaped to conformingly receive and mate with the protrusions.   
     
     
         3 . The method of  claim 1 , wherein:
 the step of providing a first moulded part comprises solidifying a first feedstock within a first mould to form the first moulded part;   the step of providing a second moulded part comprises solidifying a second feedstock within a second mould to form a second moulded part;   the step of sinter-fusing comprises applying a binding material between the one or more first-part connection-surfaces and the one or more second-part connection-surfaces fully across the received first-part connection-surfaces; and   the step of sinter-fusing further comprises sintering the positioned and adjoined first moulded part and second moulded part to form the turbomachine shrouded wheel.   
     
     
         4 . The method of  claim 3 , wherein:
 the step of providing a first moulded part includes compounding a first metal powder with a first binder to create the first feedstock; and   the step of providing a second moulded part includes compounding a second metal powder with a second binder to create the second feedstock.   
     
     
         5 . The method of  claim 4 , wherein the composition of the first feedstock, and the second feedstock, each includes the same metal powder. 
     
     
         6 . The method of  claim 4 , wherein the composition of the first feedstock, and the second feedstock, each includes the same binder. 
     
     
         7 . The method of  claim 3 , wherein the first feedstock and the second feedstock consist of the same substances. 
     
     
         8 . The method of  claim 7 , wherein the substances composing the first feedstock, and the second feedstock, are present in the same proportions. 
     
     
         9 . The method of  claim 8 , wherein the binding material is composed of the same substances in the same proportions as the first feedstock. 
     
     
         10 . The method of  claim 3 , wherein the composition of the binding material includes a binder. 
     
     
         11 . The method of  claim 10 , wherein the binding material consists of the binder. 
     
     
         12 . The method of  claim 3 , wherein:
 a) the step of providing a first moulded part includes
 forming two or more first-mould parts, 
 joining the two or more first-mould parts together to form a first mould defining a first cavity, 
 heating the first feedstock adequately to melt a first binder within the first feedstock, and 
 injecting the first feedstock into the first cavity; and 
   b) the step of providing a second moulded part includes
 forming two or more second-mould parts, 
 joining the two or more second-mould parts together to form a second mould defining a second cavity, 
 heating the second feedstock adequately to melt a second binder within the second feedstock, and 
 injecting the second feedstock into the second cavity. 
   
     
     
         13 . The method of  claim 3 , and further comprising removing a partial amount of a first binder of the first feedstock from the first moulded part after the step of solidifying the first feedstock, and prior to the step of sintering. 
     
     
         14 . The method of  claim 13 , wherein the step of removing is conducted prior to the step of applying the binding material. 
     
     
         15 . A shrouded wheel formed in accordance with the method for manufacturing a turbomachine shrouded wheel of  claim 3 . 
     
     
         16 . The method of  claim 1 , wherein:
 the one or more first-part connection-surfaces form protrusions along respective lengths of the first-part connection-surfaces; and   the one or more second-part connection-surfaces form depressions along respective lengths of the second-part connection-surfaces, the depressions being shaped and sized to receive the protrusions fully and conformingly when the first moulded part and the second moulded part are respectively positioned and adjoined to one another in the mated configuration.   
     
     
         17 . The method of  claim 16 , wherein:
 the step of positioning and adjoining includes applying a feedstock between the first-part connection-surfaces and the second-part connection-surfaces; and   the step of sinter-fusing includes sintering the positioned and adjoined first moulded part and second moulded part.   
     
     
         18 . The method of  claim 16 , wherein at least some connection-surfaces of the group of the first-part connection-surfaces and the second-part connection-surfaces form surface discontinuities spaced at intervals along their respective lengths. 
     
     
         19 . A shrouded wheel formed in accordance with the method of  claim 16 . 
     
     
         20 . A shrouded wheel, comprising:
 a wheel including a plurality of blades, the plurality of blades having one or more mating surfaces;   a shroud having the one or more receiving surfaces on a flow wall, wherein the one or more receiving surfaces are shaped and sized to receive the mating surfaces fully and conformingly when the wheel and the shroud respectively are positioned and adjoined to one another in a mated configuration, and wherein the wheel and the shroud are positioned and adjoined with respect to one another in the mated configuration;   a means for sinter-fusedly holding the blades to the flow wall through the mating surfaces and the receiving surfaces to form the shrouded wheel.