One-piece manufacturing process

Abstract

A method of making a turbomachine part, wherein the method can include machining a blank into a base having blades extending therefrom, the blades defining a channel therebetween. The method can also include forming a bridge constructed from refractory material in the channel between the blades, and forming a cover on the tops of the blades and over the channel, such that the base, the blades, and the cover form a single substantially homogenous turbomachine part once the bridge is removed.

We claim: 
     
         1 . A method for fabricating a turbomachine part, comprising:
 machining a blank into a base having a first appendage and a second appendage extending therefrom, the first appendage and the second appendage defining a channel therebetween;   filling the channel with a refractory material to form a bridge between a first top of the first appendage and a second top of the second appendage;   forming a cover on the first top and the second top and over the channel such that the base, the first appendage, the second appendage, and the cover form a single substantially homogenous structure; and   removing the bridge.   
     
     
         2 . The method of  claim 1 , further comprising curing the refractory material by heating the base, the first appendage, and the second appendage. 
     
     
         3 . The method of  claim 1 , further comprising striking off an excess portion of the refractory material such that the bridge is substantially level with the first top and the second top. 
     
     
         4 . The method of  claim 1 , further comprising depositing a layer of carbon between the refractory material and the cover, between the refractory material and the first appendage, and between the refractory material and the second appendage. 
     
     
         5 . The method of  claim 1 , wherein machining the blank comprises flaring the first top of the first appendage and the second top of the second appendage. 
     
     
         6 . The method of  claim 1 , wherein forming the cover further comprises preheating the first appendage and the second appendage to a temperature near a melting temperature thereof. 
     
     
         7 . The method of  claim 1 , wherein forming the cover comprises disposing a dam around the base such that the dam, the first top, the second top, and the bridge define a bounded region. 
     
     
         8 . The method of  claim 7 , wherein forming the cover further comprises:
 pouring a molten metal into the bounded region to melt a portion of the first top and a portion of the second top such that the portion of the first top and the portion of the second top blend with the molten metal; and   cooling the molten metal to form the turbomachine part having the single substantially homogenous structure.   
     
     
         9 . A method for fabricating a turbomachine part, comprising:
 machining a blank into a base having a first vane and a second vane extending from the base, the first vane and the second vane defining a channel therebetween;   forming a bridge across the channel and between the first vane and the second vane;   preheating the first vane and the second vane to a temperature substantially near a melting temperature thereof; and   forming a cover on the first vane, the second vane, and the bridge using a molten metal, the cover being formed such that the base, the first vane, the second vane, and the cover form a single substantially homogenous structure.   
     
     
         10 . The method of  claim 9 , wherein forming the bridge comprises:
 filling the channel with a refractory material;   curing the refractory material; and   striking off excess portions of the refractory material such that the bridge is substantially level with a first top of the first vane and a second top of the second vane.   
     
     
         11 . The method of  claim 10 , further comprising depositing a layer of carbon between the refractory material and the cover, between the refractory material and the first vane, and between the refractory material and the second vane. 
     
     
         12 . The method of  claim 9 , wherein machining the blank comprises:
 flaring a first top of the first vane and a second top of the second vane; and   flaring a first bottom of the first vane and a second bottom of the second vane.   
     
     
         13 . The method of  claim 9 , wherein forming the cover comprises disposing a dam around the base such that the dam, a first top of the first vane, a second top of the second vane, and the bridge define a bounded region. 
     
     
         14 . The method of  claim 13 , wherein forming the cover further comprises:
 pouring the molten metal into the bounded region such that a melt zone of the first top, a melt zone of the second top, and the molten metal blend with one another; and   cooling the molten metal to form the turbomachine part having the single substantially homogenous structure.   
     
     
         15 . A method for making a turbomachine part, comprising:
 machining a blank into a base having a first vane and a second vane extending therefrom, the first vane and the second vane defining a channel therebetween;   filling the channel with a refractory material to form a bridge between a first top of the first vane and a second top of the second vane;   curing the refractory material;   preheating the first vane and the second vane to a preheating temperature below a melting temperature thereof; and   forming a cover on the first top and the second top and over the bridge with a molten metal, the cover being formed such that the base, the first vane, the second vane, and the cover form a substantially homogenous structure.   
     
     
         16 . The method of  claim 15 , wherein machining the blank comprises flaring a first bottom of the first vane and a second bottom of the second vane. 
     
     
         17 . The method of  claim 15 , wherein machining the blank comprises flaring the first top of the first vane and the second top of the second vane. 
     
     
         18 . The method of  claim 15 , wherein forming the cover comprises:
 disposing a dam around an outside diameter of the base such that the dam, the first top of the first vane, the second top of the second vane, and the bridge define a bounded region; and   pouring the molten metal into the bounded region to melt a portion of the first top and a portion of the second top.   
     
     
         19 . The method of  claim 18 , wherein forming the cover further comprises controlling the preheating temperature and a temperature of the molten metal to form the substantially homogenous structure. 
     
     
         20 . The method of  claim 19 , wherein forming the cover further comprises controlling the preheating temperature and a temperature of the molten metal to prevent oxidation of the first vane, the second vane, and the cover.