Method for manufacturing a titanium part through initial beta forging

Abstract

The invention relates to a method of fabricating a titanium alloy part, the method comprising: heating the part to a temperature T 1 so that the temperature of the part is substantially uniform, performing an initial forging operation on the part, followed immediately by quenching the part down to ambient temperature; and heating the part to a temperature T 2 , followed by a final forging operation on the part at the temperature T 2 followed immediately by quenching the part, the final forging operation being suitable for giving the part its final shape; the temperature T 1 being higher than the β-transus temperature of the alloy, the temperature T 2 being lower than the β-transus temperature, the only heating of the part to above the β-transus temperature being the heating to the temperature T 1 , the initial forging preceding the final forging, and the initial forging being performed as soon as the temperature of the part is substantially uniform, the method being characterized in that the quenching immediately following the initial forging is performed at a speed faster than 150° C./min, with the deformation ratio during the initial forging being greater than 0.7.

1 . A method of fabricating a part out of titanium alloy, the method comprising:
 heating said part to a temperature T 1  so that the temperature of said part is substantially uniform, performing an initial forging operation on said part, followed immediately by quenching said part down to ambient temperature; and   heating said part to a temperature T 2 , followed by a final forging operation on said part at said temperature T 2  followed immediately by quenching said part, said final forging operation being suitable for giving said part its final shape;   said temperature T 1  being higher than the β-transus temperature of said alloy, said temperature T 2  being lower than the β-transus temperature, the only heating of said part to above the β-transus temperature being the heating to the temperature T 1 , said initial forging preceding said final forging, and said initial forging being performed as soon as the temperature of said part is substantially uniform, said method being characterized in that said quenching immediately following said initial forging is performed at a speed faster than 150° C./min, with the deformation ratio during said initial forging being greater than 0.7.   
     
     
         2 . A method according to  claim 1 , characterized in that said deformation ratio is greater than 1. 
     
     
         3 . A method according to  claim 1 , characterized in that said deformation ratio is greater than 1.6. 
     
     
         4 . A method according to any one of  claims 1  to  3 , characterized in that said quenching is performed at a speed substantially equal to 250° C./min. 
     
     
         5 . A method according to any one of  claims 1  to  4 , characterized in that said final forging is followed by an αβ phase tempering operation. 
     
     
         6 . A method according to any one of  claims 1  to  5 , characterized in that said titanium alloy is an alloy of the αβ or quasi-α titanium family. 
     
     
         7 . A method according to any one of  claims 1  to  6 , characterized in that said titanium alloy is selected from TA6V alloy and Ti6242 alloy. 
     
     
         8 . A method according to any one of  claims 1  to  7 , characterized in that said shape of the part immediately after the initial forging is of the frustoconical or diabolo type. 
     
     
         9 . A method according to any one of  claims 1  to  8 , characterized in that said part is a body of revolution for an aviation turbine. 
     
     
         10 . A method according to any one of  claims 1  to  8 , characterized in that said part is a disk for an aviation turbine. 
     
     
         11 . A method according to any one of  claims 1  to  8 , characterized in that said part is a drum for an aviation turbine.