Processing of titanium-aluminum-vanadium alloys and products made thereby

Abstract

A method of forming an article from an α−β titanium including, in weight percentages, from about 2.9 to about 5.0 aluminum, from about 2.0 to about 3.0 vanadium, from about 0.4 to about 2.0 iron, from about 0.2 to about 0.3 oxygen, from about 0.005 to about 0.3 carbon, from about 0.001 to about 0.02 nitrogen, and less than about 0.5 of other elements. The method comprises cold working the α−β titanium alloy.

What is claimed is:  
     
         1 . A method of forming an article from an α−β titanium alloy comprising, in weight percentages, from about 2.9 to about 5.0 aluminum, from about 2.0 to about 3.0 vanadium, from about 0.4 to about 2.0 iron, from about 0.2 to about 0.3 oxygen, from about 0.005 to about 0.3 carbon, from about 0.001 to about 0.02 nitrogen, and less than about 0.5 of other elements, the method comprising: 
 cold working the α−β titanium alloy.  
 
     
     
         2 . The method of  claim 1 , wherein prior to cold working the α−β titanium alloy, the α−β titanium alloy is worked at a temperature greater than 1600° F. to provide the alloy with a microstructure conducive to subsequent cold deformation.  
     
     
         3 . The method of  claim 1 , wherein cold working the α−β titanium alloy is conducted at a temperature in the range of ambient temperature up to less than 1250° F.  
     
     
         4 . The method of  claim 1 , wherein cold working the α−β titanium alloy is conducted at a temperature in the range of ambient temperature up to 1000° F.  
     
     
         5 . The method of  claim 1 , wherein cold working the α−β titanium alloy comprises working the α−β titanium alloy at less than 1250° F. by at least one technique selected from the group consisting of rolling, forging, extruding pilgering, rocking, drawing, flow-turning, liquid compressive forming, gas compressive forming, hydro-forming, bulge forming, roll forming, stamping, fine-blanking, die pressing, deep drawing, coining, spinning, swaging, impact extruding, explosive forming, rubber forming, back extrusion, piercing, spinning, stretch forming, press bending, swaging, electromagnetic forming, and cold heading.  
     
     
         6 . The method of  claim 1 , wherein the article is selected from the group consisting of a coil, a sheet, a strip, a foil, a plate, a bar, a rod, a wire, a tubular hollow, a pipe, a tube, a cloth, a mesh, a structural member, a cone, a cylinder, a duct, a pipe, a nozzle, a honeycomb structure, a fastener, a rivet and a washer.  
     
     
         7 . The method of  claim 1 , where the α−β titanium alloy has lower flow stress than Ti-6Al-4V alloy.  
     
     
         8 . The method of  claim 1 , wherein cold working the α−β titanium alloy comprises cold rolling the α−β titanium alloy, and wherein the article is a generally flat-rolled article selected from the group consisting of a sheet, a strip, a foil and a plate.  
     
     
         9 . The method of  claim 8 , wherein cold rolling the α−β titanium alloy reduces a thickness of the α−β titanium alloy by about 30% to about 60% prior to annealing the α−β titanium alloy.  
     
     
         10 . The method of  claim 8 , wherein cold working the α−β titanium alloy comprises reducing a thickness of the α−β titanium alloy by at least two cold rolling steps, and wherein the method further comprises: 
 annealing the α−β titanium alloy intermediate successive cold rolling steps, wherein annealing the α−β titanium alloy reduces stresses within the α−β titanium alloy.  
 
     
     
         11 . The method of  claim 10 , wherein at least one anneal intermediate successive cold rolling steps is conducted on a continuous anneal furnace line.  
     
     
         12 . The method of  claim 10 , wherein in at least one of the cold rolling steps, a thickness of the α−β titanium alloy is reduced by 30% to 60%.  
     
     
         13 . The method of  claim 1 , wherein cold working the α−β titanium alloy comprises rolling the α−β titanium alloy, and wherein the article is selected from the group consisting of a bar, a rod, and a wire.  
     
     
         14 . The method of  claim 1 , wherein cold working the α−β titanium alloy comprises at least one of pilgering and rocking the α−β titanium alloy, and wherein the article is one of a tube and a pipe.  
     
     
         15 . The method of  claim 1 , wherein cold working the α−β titanium alloy comprises drawing the α−β titanium alloy, and wherein the article is selected from the group consisting of a rod, a wire, a bar and a tubular hollow.  
     
     
         16 . The method of  claim 1 , wherein cold working the α−β titanium alloy comprises at least one of flow-turning, shear spinning and spinning the α−β titanium alloy, and wherein the article has axial symmetry.  
     
     
         17 . The method of  claim 1 , wherein the article has a thickness up to 4 inches, and wherein room temperature properties of the article include tensile strength of at least 120 KSI, ultimate tensile strength of at least 130 KSI and elongation of at least 10%.  
     
     
         18 . The method of  claim 17 , wherein the article has elongation of at least 10%.  
     
     
         19 . The method of  claim 1 , wherein yield strength, ultimate tensile strength and elongation properties of the article are each at least as great as for Ti-6Al-4V.  
     
     
         20 . The method of  claim 1 , wherein the article can be bent around a radius of 4 times its thickness without failure of the article.  
     
     
         21 . A method of making an article, the method comprising: 
 providing an α−β titanium alloy comprising, in weight percentages, from about 2.9 to about 5.0 aluminum, from about 2.0 to about 3.0 vanadium, from about 0.4 to about 2.0 iron, from about 0.2 to about 0.3 oxygen, from about 0.005 to about 0.3 carbon, from about 0.001 to about 0.02 nitrogen, and less than about 0.5 of other elements; and    working the alloy at a temperature less than 1250° F.    
     
     
         22 . A method of forming an article from an α−β titanium alloy comprising, in weight percentages, from about 2.9 to about 5.0 aluminum, from about 2.0 to about 3.0 vanadium, from about 0.4 to about 2.0 iron, from about 0.2 to about 0.3 oxygen, from about 0.005 to about 0.3 carbon, from about 0.001 to about 0.02 nitrogen, and less than about 0.5 of other elements, the method comprising: 
 reducing a thickness of the α−β titanium alloy by at least two cold rolling steps, wherein in at least one cold rolling step a thickness of the α−β titanium alloy is reduced by 30% to 60%; and  
 annealing the α−β titanium alloy intermediate successive cold rolling steps and thereby reducing stresses within the α−β titanium alloy.  
 
     
     
         23 . The method of  claim 22 , wherein the article is selected from the group consisting of a sheet, a strip, a foil and a plate.  
     
     
         24 . The method of  claim 22 , wherein at least one anneal intermediate successive cold rolling step is conducted on a continuous anneal furnace line.  
     
     
         25 . A cold worked article of an α−β titanium alloy comprising, in weight percentages, from about 2.9 to about 5.0 aluminum, from about 2.0 to about 3.0 vanadium, from about 0.4 to about 2.0 iron, from about 0.2 to about 0.3 oxygen, from about 0.005 to about 0.3 carbon, from about 0.001 to about 0.02 nitrogen, and less than about 0.5 of other elements.  
     
     
         26 . The cold worked article of  claim 25 , wherein the article is selected from the group consisting of a coil, a sheet, a strip, a foil, a plate, a bar, a rod, a wire, a tubular hollow, a pipe, a tube, a cloth, a mesh, a structural member, a cone, a cylinder, a duct, a pipe, a nozzle, a honeycomb structure, a fastener, a rivet and a washer.  
     
     
         27 . The method of  claim 25 , wherein the article has a thickness up to 4 inches, and wherein room temperature properties of the article include tensile strength of at least 120 KSI and ultimate tensile strength of at least 130 KSI.  
     
     
         28 . The method of  claim 25 , wherein the article has elongation of at least 10%.  
     
     
         29 . The method of  claim 25  wherein the article can be bent around a radius of 4 times its thickness without failure of the article.  
     
     
         30 . The article of  claim 25 , wherein the article is selected from the group consisting of a cold rolled article, a cold forged article, a cold pilgered article, a cold extruded article, a cold drawn article, a flow-turned article, a compressively formed article, a hydro-formed article, a cold roll formed article, a cold stamped article, a fine-blanked article, a cold die pressed article, a cold deep drawn article, a coined article, a cold spun article, a cold swaged article, an impact extruded article, and explosive formed article, a rubber formed article, a back extruded article, a pierced article, a stretch formed article, a press bent article, an electromagnetically formed article, and cold headed article.  
     
     
         31 . A method of making an armor plate from an α−β titanium alloy comprising, in weight percentages, from about 2.9 to about 5.0 aluminum, from about 2.0 to about 3.0 vanadium, from about 0.4 to about 2.0 iron, from about 0.2 to about 0.3 oxygen, from about 0.005 to about 0.3 carbon, from about 0.001 to about 0.02 nitrogen, and less than about 0.5 of other elements, the method comprising: 
 rolling the alloy at a temperature no greater than 400° F. below the T β  of the alloy.  
 
     
     
         32 . The method of  claim 31 , wherein rolling the alloy at a temperature less than 1250° F. comprises rolling the alloy at a temperature that is in the range of 400° F. to 700° F. below the T β  of the alloy.