Method for producing a beta-processed alpha-beta titanium-alloy article

Abstract

A titanium-alloy article is produced by providing a workpiece of an alpha-beta titanium alloy having a beta-transus temperature, and thereafter mechanically working the workpiece at a mechanical-working temperature above the beta-transus temperature. The mechanically worked workpiece is solution heat treated at a solution-heat-treatment temperature of from about 175° F. below the beta-transus temperature to about 25° F. below the beta-transus temperature, quenched, overage heat treated at an overage-heat-treatment temperature of from about 400° F. below the beta-transus temperature to about 275° F. below the beta-transus temperature, and cooled from the overage-heat-treatment temperature.

1 . A method for producing a titanium-alloy article, comprising the steps of
 providing a workpiece of an alpha-beta titanium alloy having a beta-transus temperature; thereafter   mechanically working the workpiece at a mechanical-working temperature above the beta-transus temperature; thereafter   solution heat treating the workpiece at a solution-heat-treatment temperature of from about 175° F. below the beta-transus temperature to about 25° F. below the beta-transus temperature, and quenching the workpiece from the solution-heat-treatment temperature; and thereafter   overage heat treating the workpiece at an overage-heat-treatment temperature of from about 400° F. below the beta-transus temperature to about 275° F. below the beta-transus temperature, and cooling the workpiece from the overage-heat-treatment temperature.   
   
   
       2 . The method of  claim 1 , wherein the step of providing the workpiece includes the step of
 providing the workpiece having a nominal composition in weight percent selected from the group consisting of Ti-6Al-2Sn-4Zr-2Mo, Ti-6Al-2Sn-4Zr-6Mo, Ti-6Al-2Sn-2Zr-2Mo-2Cr-0.25Si, and Ti-5Al-4Mo-4Cr-2Sn-2Zr.   
   
   
       3 . The method of  claim 1 , wherein the step of mechanically working includes the step of
 forging the workpiece at the mechanical-working temperature above the beta-transus temperature.   
   
   
       4 . The method of  claim 1 , wherein the step of solution heat treating includes the step of
 solution heat treating the workpiece at the solution-heat-treatment temperature of from about 175° F. below the beta-transus temperature to about 125° F. below the beta-transus temperature.   
   
   
       5 . The method of  claim 1 , wherein the step of solution heat treating includes the step of
 solution heat treating the workpiece at the solution-heat-treatment temperature of from about 100° F. below the beta-transus temperature to about 25° F. below the beta-transus temperature.   
   
   
       6 . The method of  claim 1 , including an additional step, after the step of overage heat treating, of
 utilizing the workpiece by machining the workpiece or using the workpiece in service.   
   
   
       7 . The method of  claim 1 , including the additional steps, after the step of solution heat treating and before the step of overage heat treating of
 precipitation heat treating the workpiece at a temperature of from about 1100° F. to about 1225° F.; and thereafter   utilizing the workpiece by machining the workpiece or using the workpiece in service.   
   
   
       8 . A method for producing a titanium-alloy article, comprising the steps of
 providing a workpiece of an alpha-beta titanium alloy having a beta-transus temperature; thereafter   mechanically working the workpiece at a mechanical-working temperature above the beta-transus temperature; thereafter   solution heat treating the workpiece at a solution-heat-treatment temperature of from about 1450° F. to about 1600° F., and quenching the workpiece from the solution-heat-treatment temperature; and thereafter   overage heat treating the workpiece at an overage-heat-treatment temperature of from about 1225° F. to about 1350° F., and cooling the workpiece from the overage-heat-treatment temperature.   
   
   
       9 . The method of  claim 8 , wherein the step of providing the workpiece includes the step of
 providing the workpiece having a nominal composition in weight percent selected from the group consisting of Ti-6Al-2Sn-4Zr-2Mo, Ti-6Al-2Sn-4Zr-6Mo, Ti-6Al-2Sn-2Zr-2Mo-2Cr-0.25Si, and Ti-5Al-4Mo-4Cr-2Sn-2Zr.   
   
   
       10 . The method of  claim 8 , wherein the step of providing the workpiece includes the step of
 providing the workpiece that is a precursor of a component of a gas turbine engine.   
   
   
       11 . The method of  claim 8 , wherein the step of mechanically working includes the step of
 forging the workpiece at the mechanical-working temperature above the beta-transus temperature.   
   
   
       12 . The method of  claim 8 , wherein the step of solution heat treating includes the step of
 solution heat treating the workpiece at the solution-heat-treatment temperature of from about 1450° F. to about 1500° F.   
   
   
       13 . The method of  claim 8 , wherein the step of solution heat treating includes the step of
 solution heat treating the workpiece at the solution-heat-treatment temperature of from about 1525° F. to about 1600° F.   
   
   
       14 . The method of  claim 8 , including an additional step, after the step of overage heat treating, of
 utilizing the workpiece by machining the workpiece or using the workpiece in service.   
   
   
       15 . The method of  claim 8 , including additional steps, after the step of overage heat treating, of
 utilizing the workpiece by machining the workpiece or using the workpiece in service, and   second overage heat treating the workpiece at a second overage-heat-treatment temperature of from about 1225° F. to about 1350° F., and cooling the workpiece from the second overage-heat-treatment temperature.   
   
   
       16 . The method of  claim 8 , including additional steps, after the step of overage heat treating, of
 utilizing the workpiece by machining the workpiece or using the workpiece in service, thereafter   second solution heat treating the workpiece at a second solution-heat-treatment temperature of from about 1450° F. to about 1600° F., and quenching the workpiece from the second solution-heat-treatment temperature, and thereafter   second overage heat treating the workpiece at a second overage-heat-treatment temperature of from about 1225° F. to about 1350° F., and cooling the workpiece from the second overage-heat-treatment temperature.   
   
   
       17 . The method of  claim 8 , wherein the workpiece is an alpha-beta titanium alloy having a beta-transus temperature and having a nominal composition in weight percent of Ti-5Al-4Mo-4Cr-2Sn-2Zr, wherein the workpiece is a precursor of a component of a gas turbine engine. 
   
   
       18 . A method for producing a titanium-alloy article, comprising the steps of
 providing a workpiece of an alpha-beta titanium alloy having a beta-transus temperature; thereafter   forging the workpiece into a component of a gas turbine engine at a temperature above the beta-transus temperature; thereafter   solution heat treating the workpiece at a solution-heat-treatment temperature of from about 175° F. below the beta-transus temperature to about 25° F. below the beta-transus temperature, and quenching the workpiece from the solution-heat-treatment temperature; and thereafter   overage heat treating the workpiece at an overage-heat-treatment temperature of from about 400° F. below the beta-transus temperature to about 275° F. below the beta-transus temperature, and cooling the workpiece from the overage-heat-treatment temperature.