Method for forging a titanium alloy thermomechanical part

Abstract

A method for forging a thermomechanical part and including: providing a billet produced in a titanium alloy having a beta transus temperature; carrying out at least one operation of forging a blank of the billet at a temperature T 1 lower than the beta transus temperature T b from before carrying out the forging operation whereby a blank is completed; carrying out a final forging the blank at a temperature T 2 greater than the beta transus temperature T b from before carrying out the forging operation whereby a blank is completed. The forging operation from the blank-forging carries out, on every point of the billet, a deformation greater than a minimum deformation rate. The method can be used for a rotating part of a turbine engine.

1 - 16 . (canceled) 
     
     
         17 . A method of forging a thermomechanical part of beta or alpha/beta titanium alloy, the method comprising:
 providing a billet made from a titanium alloy possessing a beta transus temperature T β ;   performing at least one blank forging operation on the billet, in which the billet is heated to a temperature T 1  lower than the beta transus temperature T β  prior to performing the forging operation proper during which the billet is subjected to plastic deformation, thereby obtaining a blank, and then allowing the blank to cool; and   performing a final forging operation on the blank, in which the blank is heated to a temperature T 2  higher than the beta transus temperature T β  prior to performing the forging operation proper during which the blank is subjected to plastic deformation, thereby obtaining a forging, and then cooling the forging;   wherein the forging operation of the blank forging implements, at all points of the billet, local deformation that is greater than a minimum deformation ratio.   
     
     
         18 . A forging method according to  claim 17 , wherein the minimum deformation ratio is not less than 0.2. 
     
     
         19 . A forging method according to  claim 17 , wherein the minimum deformation ratio is 0.3. 
     
     
         20 . A forging method according to  claim 17 , wherein the minimum deformation ratio is 0.4. 
     
     
         21 . A forging method according to  claim 17 , comprising at least first and second blank forging operations, and wherein for the first or the second blank forging operations, the forging operation implements, at all points in the billet, deformation that is greater than a minimum deformation ratio of 0.3. 
     
     
         22 . A forging method according to  claim 17 , comprising a single blank forging in which, during the blank forging, the forging operation implements, at all points of the billet, deformation that is greater than a minimum deformation ratio of 0.3. 
     
     
         23 . A forging method according to  claim 17 , comprising at least two blank forging operations, and wherein for the at least two successive blank forging operations, the forging operation implements, at all points of the billet, deformation that is greater than a minimum deformation ratio of 0.2. 
     
     
         24 . A forging method according to  claim 17 , comprising at least two blank forging operations, and wherein for each blank forging operation, the forging operation implements, at all points of the billet, deformation that is greater than a minimum deformation ratio of 0.2. 
     
     
         25 . A forging method according to  claim 17 , wherein the titanium alloy is an alpha/beta type alloy. 
     
     
         26 . A forging method according to  claim 17 , wherein the titanium alloy is “Ti 6242” or Ti-6Al-2Sn-4Zr-2Mo. 
     
     
         27 . A forging method according to  claim 17 , wherein the titanium alloy is “Ti 17” or Ti-5Al-4Mo-4Cr-2Sn-2Zr. 
     
     
         28 . A method of fabricating a thermomechanical part made of titanium alloy, the fabrication method comprising a forging method according to  claim 17 . 
     
     
         29 . A thermomechanical part made of titanium alloy in which the fabrication method includes the forging method according to  claim 17 , the thermomechanical part being a forging of beta-forged alpha/beta alloy presenting a microstructure that is fine and uniform with a grain size of an order of 50 μm to 100 μm. 
     
     
         30 . A thermomechanical part according to  claim 29 , forming a rotary part of a turbomachine. 
     
     
         31 . A thermomechanical part according to  claim 29 , forming a high-pressure compressor disk. 
     
     
         32 . A turbomachine comprising a thermomechanical part according to  claim 29 .