Method for processing beta titanium alloys

Abstract

An embodiment of the present invention comprises processing a beta titanium alloy by a method including the steps of cold working the alloy and then direct aging the alloy for a total aging time of less than 4 hours. Any beta titanium alloy may be used in the method, for example, Ti-38-644 alloy. The method may include fabricating the alloy into an article of manufacture such as, for example, a bar, wire, a coil spring. The method may be utilized to produce articles with high tensile strength while retain ductility. Another embodiment of the present invention is a method for producing a spring or other article of manufacture from a beta titanium alloy. The beta titanium alloy may be, for example, the alloy comprising, by weight, 3.0% to 4.0% aluminum, 7.5 to 8.5% vanadium, 5.5 to 6.5% chromium, 3.5 to 4.5% molybdenum, 3.5 to 4.5% zirconium, and titanium. The alloy may be hot worked, cold worked to provide a 5% to 60% reduction, and direct aged for a total time of less than 4 hours. Any cold working technique may be used in embodiments of the present invention. Useful cold working techniques include, but are not limited to, compression processes, drawing, wire drawing, tube drawing, deep drawing, rolling, contour forming, extruding, cold heading, swaging, coining, forging, tension processes, stretch forming, and spinning.

1 . A method for processing titanium alloys, the method comprising: 
 cold working a beta titanium alloy; and    direct aging the beta titanium alloy for a total aging time of less than 4 hours.    
     
     
         2 . The process of  claim 1 , wherein the beta titanium alloy comprises at least one of aluminum, vanadium, molybdenum, chromium, and zirconium.  
     
     
         3 . The process of  claim 1 , further comprising: 
 hot rolling the beta titanium alloy prior to cold working the beta titanium alloy.    
     
     
         4 . The process of  claim 3 , wherein cold working the beta titanium alloy comprises cold working the beta titanium alloy to at least a 5% reduction.  
     
     
         5 . The process of  claim 4 , wherein cold working the beta titanium alloy comprises cold working the beta titanium alloy to at least a 15% reduction.  
     
     
         6 . The process of  claim 5 , wherein cold working the beta titanium alloy comprises cold working the beta titanium alloy to less than 60% reduction.  
     
     
         7 . The process of  claim 6 , wherein cold working the beta titanium alloy comprises cold working the beta titanium alloy to less than 35% reduction.  
     
     
         8 . The process of  claim 7 , wherein cold working the beta titanium alloy comprises cold working the beta titanium alloy to less than 20% reduction.  
     
     
         9 . The process of claims  1 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy in the temperature range about 800° F. (427° C.) to about 1200° F. (649° C.).  
     
     
         10 . The process of  claim 1 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy in the temperature range of about 800° F. (427° C.) to about 1000° F. (538° C.).  
     
     
         11 . The process of  claim 1 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy in the temperature range about 900° F. (882° C.) to about 1000° F. (538° C.).  
     
     
         12 . The process of  claim 1 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 3 hours.  
     
     
         13 . The process of  claim 1 , wherein the direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 2 hours.  
     
     
         14 . The process of  claim 1 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 1 hour.  
     
     
         15 . The process of  claim 1 , wherein the direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 45 minutes.  
     
     
         16 . The process of  claim 1 , wherein the beta titanium alloy comprises, by weight, 3.0 to 4.0% aluminum, 7.5 to 8.5% vanadium, 5.5 to 6.5% chromium, 3.5 to 4.5% molybdenum, 3.5 to 4.5% zirconium 3.5 to 4.5%, and titanium.  
     
     
         17 . A process for producing an article of manufacture, comprising: 
 providing a beta titanium alloy comprising, by weight, 3.0 to 4.0% aluminum, 7.5 to 8.5% vanadium, 5.5 to 6.5% chromium, 3.5 to 4.5% molybdenum, 3.5 to 4.5% zirconium, and titanium;    hot working the beta titanium alloy;    cold working the beta titanium alloy to provide a 5 to 60% reduction;    direct aging the beta titanium alloy for a total aging time of less than 2 hours at a temperature in the range about 800° F. (427° C.) to about 1100° F.(593° C.).    
     
     
         18 . The process of  claim 17 , wherein the article of manufacture is a spring.  
     
     
         19 . The process of  claim 17 , wherein cold working the beta titanium alloy comprises drawing the beta titanium alloy through a die.  
     
     
         20 . The process of  claim 17 , wherein hot working the beta titanium alloy comprises forming the beta titanium alloy into a bar, a rod, or a coil.  
     
     
         21 . The process of  claim 17 , wherein direct aging the beta titanium alloy includes a total aging time less than one hour.  
     
     
         22 . The process of  claim 17 , wherein direct aging the beta titanium alloy includes a total aging time less than forty-five minutes.  
     
     
         23 . The process of  claim 22 , wherein direct aging the beta titanium alloy includes a direct aging temperature in the range about 900° F. (482° C.) to about 1000° F. (538° C.).  
     
     
         24 . The process of  claim 18 , wherein the spring is a component of an automobile, snowmobile, motorcycle, recreational vehicle, or engine.  
     
     
         25 . The process of  claim 17 , further comprising: 
 centerless grinding the beta titanium alloy; and    annealing the beta titanium alloy prior to cold working the beta titanium alloy.    
     
     
         26 . The process of  claim 25 , wherein cold working the beta titanium alloy comprises drawing the beta titanium alloy through a die.  
     
     
         27 . The process of  claim 17 , wherein the cold working of the alloy provides a 5 to 35% reduction.  
     
     
         28 . A method of processing a titanium alloy, comprising: 
 direct aging a cold worked beta titanium alloy for a total aging time of less than 4 hours.    
     
     
         29 . The process of  claim 28 , wherein the beta titanium alloy comprises at least one of aluminum, vanadium, molybdenum, chromium, and zirconium.  
     
     
         30 . The process of  claim 28 , further comprising: 
 hot rolling the beta titanium alloy prior to cold working the beta titanium alloy.    
     
     
         31 . The process of claims  28 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy in the temperature range about 800° F. (427° C.) to about 1200° F. (649° C.).  
     
     
         32 . The process of  claim 28 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy in the temperature range of about 800° F. (427° C.) to about 1000° F. (538° C.).  
     
     
         33 . The process of  claim 28 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy in the temperature range about 900° F. (882° C.) to about 1000° F. (538° C.).  
     
     
         34 . The process of  claim 28 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 3 hours.  
     
     
         35 . The process of  claim 28 , wherein the direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 2 hours.  
     
     
         36 . The process of  claim 28 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 1 hour.  
     
     
         37 . The process of  claim 28 , wherein the direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 45 minutes.  
     
     
         38 . The process of  claim 28 , wherein the beta titanium alloy comprises, by weight, 3.0 to 4.0% aluminum, 7.5 to 8.5% vanadium, 5.5 to 6.5% chromium, 3.5 to 4.5% molybdenum, 3.5 to 4.5% zirconium 3.5 to 4.5%, and titanium.  
     
     
         39 . An article of manufacture prepared by a process, comprising: 
 cold working an article, wherein the article comprises a beta titanium alloy; and    direct aging the article for a total aging time of less than 4 hours.    
     
     
         40 . The article of manufacture of  claim 39 , wherein the article is one of a bar, a rod, or a coil.  
     
     
         41 . The article of manufacture of  claim 39 , wherein the beta titanium alloy comprises, by weight, 3.0 to 4.0% aluminum, 7.5 to 8.5% vanadium, 5.5 to 6.5% chromium, 3.5 to 4.5% molybdenum, 3.5 to 4.5% zirconium 3.5 to 4.5%, and titanium.  
     
     
         42 . The article of manufacture of  claim 39 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy in the temperature range about 800° F. (427° C.) to about 1200° F. (649° C.).  
     
     
         43 . The article of manufacture of  claim 39 , wherein the direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 2 hours.  
     
     
         44 . The article of manufacture of  claim 39 , wherein direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 1 hour.  
     
     
         45 . The article of manufacture of  claim 39 , wherein the direct aging the beta titanium alloy comprises direct aging the beta titanium alloy for less than 45 minutes.