Method for manufacturing superelastic beta titanium articles and the articles derived therefrom

Abstract

An article is manufactured from a composition comprising about 8 to about 10 wt % molybdenum, about 2.8 to about 6 wt % aluminum, up to about 2 wt % chromium, up to about 2 wt % vanadium, up to about 4 wt % niobium, with the balance being titanium, wherein the weight percents are based on the total weight of the alloy composition. An article is manufactured by a method comprising forming a shape from a composition comprising about 8 to about 10 wt % molybdenum, about 2.8 to about 6 wt % aluminum, up to about 2 wt % chromium, up to about 2 wt % vanadium, up to about 4 wt % niobium, with the balance being titanium, wherein the weight percents are based on the total weight of the alloy composition; cold working the shape; and heat treating the shape.

What is claimed is:  
     
         1 . An article manufactured from a composition comprising: 
 titanium; and    a molybdenum equivalent weight of about 7 to about 11 wt %, wherein the weight percents are based upon the total weight of the alloy composition, wherein the composition is superelastic and/or pseudoelastic.    
     
     
         2 . The article of  claim 1 , wherein the molybdenum equivalent weight is determined by the equation (1)  
         MO   eq. =1.00Mo+0.28Nb+0.22Ta+0.67V+1.43Co+1.60Cr+0.77Cu+2.90Fe+1.54Mn+1.11Ni+0.44W−1.00Al  (1)  
       or the equation (2)  
         Mo   eq. =1.00Mo+0.28Nb+0.22Ta+0.67V+1.43Co+1.60Cr+0.77Cu+2.90Fe+1.54Mn+1.11Ni+0.44W+0.25(Sn+ Zr+Hf)−1.00Al  (2)  
       wherein Mo is molybdenum, Nb is niobium, Ta is tantalum, V is vanadium, Co is cobalt, Cr is chromium, Cu is copper, Fe is iron, Mn is manganese, Ni is nickel, W is tungsten, Al is aluminum, S is tin, Zr is zirconium and Hf is hafnium; wherein the aluminum can be substituted by carbon, boron, germanium and/or gallium; and wherein the respective chemical symbols represent the amounts of the respective elements in weight percent based on the total weight of the alloy composition.  
     
     
         3 . The article of  claim 1 , having a composition comprising: 
 about 8 to about 10 wt % molybdenum,    about 2.8 to about 6 wt % aluminum,    up to about 2 wt % chromium,    up to about 2 wt % vanadium,    up to about 4 wt % niobium, with the balance being titanium, wherein the weight percents are based on the total weight of the alloy composition.    
     
     
         4 . The article of  claim 1 , wherein the composition is cold worked and/or solution treated.  
     
     
         5 . The article of  claim 1 , wherein the composition has an elastic recovery of greater than or equal to about 75% of the applied change in length, when the applied change in length is 2% of the original length.  
     
     
         6 . The article of  claim 1 , wherein the composition has an elastic recovery of greater than or equal to about 50% of the applied change in length when the applied change in length is 4% of the original length.  
     
     
         7 . The article of  claim 1 , wherein the composition after cold working has a reduction in the elastic modulus of greater than or equal to about 10% when compared with the elastic modulus of an equivalent heat treated composition.  
     
     
         8 . The article of  claim 1 , wherein the composition after cold working has a reduction in the elastic modulus of greater than or equal to about 20% when compared with the elastic modulus of an equivalent heat treated composition.  
     
     
         9 . The article of  claim 1 , wherein the composition after cold working has a reduction in the elastic modulus of greater than or equal to about 25% when compared with the elastic modulus of an equivalent heat treated composition.  
     
     
         10 . The article of  claim 1 , wherein the composition has a β phase or an a phase and a β phase.  
     
     
         11 . The article of  claim 1 , wherein the article is a medical device.  
     
     
         12 . The article of  claim 1 , wherein the medical device is a stent or a guide wire.  
     
     
         13 . The article of  claim 1 , wherein the medical device has a welded joint.  
     
     
         14 . The article of  claim 1 , wherein the medical device has a weld.  
     
     
         15 . The article of  claim 1 , wherein the article comprises an orthodontic arch wire, a dental implant, an orthopedic device or an eyewear frame.  
     
     
         16 . The article of  claim 15 , wherein the orthopedic device is used in bone.  
     
     
         17 . The article of  claim 15 , wherein the orthopedic device is used in the hip, knees, shoulder, elbows, or spine.  
     
     
         18 . The article of  claim 1 , wherein the article comprises at least a portion of a golf club.  
     
     
         19 . The article of  claim 18 , wherein the article is welded or brazed to the golf club.  
     
     
         20 . The article of  claim 1 , wherein the article comprises a golf club head.  
     
     
         21 . The article of  claim 1 , wherein the article comprises an insert for a golf club head.  
     
     
         22 . The article of  claim 21 , wherein the insert is welded, brazed or mechanically inserted onto the golf club head.  
     
     
         23 . The article of  claim 22 , wherein the insert is held in the golf club head by a tight toleranced fit.  
     
     
         24 . The article of  claim 1 , wherein the article has a welded joint.  
     
     
         25 . The article of  claim 1 , wherein the article has a brazed joint.  
     
     
         26 . The article of  claim 1 , wherein the article further comprises a portion having linear elastic properties.  
     
     
         27 . The article of  claim 1 , wherein the article further comprises a polymeric coating.  
     
     
         28 . An article manufactured from a composition comprising: 
 about 8.9 wt % molybdenum, about 3.03 wt % aluminum, about 1.95 wt % vanadium, about 3.86 wt % niobium, with the balance being titanium.    
     
     
         29 . The article of  claim 28 , wherein the article is a medical device.  
     
     
         30 . The article of  claim 28 , wherein the medical device is a stent, a catheter introducer, a dental implant, a guide wire, an orthodontic arch wire, an orthopedic device used in bones or tissue, or an eyewear frame.  
     
     
         31 . The article of  claim 28 , wherein the article comprises at least a portion of a golf club.  
     
     
         32 . The article of  claim 28 , wherein the article comprises a golf club head.  
     
     
         33 . The article of  claim 28 , wherein the article comprises an insert for a golf club head and further wherein the insert is welded or brazed to the golf club head.  
     
     
         34 . The article of  claim 28 , wherein the article has a welded joint.  
     
     
         35 . The article of  claim 28 , wherein the article has a soldered joint.  
     
     
         36 . The article of  claim 28 , wherein the article further comprises a portion having linear elastic properties.  
     
     
         37 . The article of  claim 28 , wherein the article further comprises a portion having pseudoelastic or superelastic properties.  
     
     
         38 . The article of  claim 28 , wherein the article further comprises a polymeric coating.  
     
     
         39 . An article manufactured from a composition comprising: 
 about 9.34 wt % molybdenum, about 3.01 wt % aluminum, about 1.95 wt % vanadium, about 3.79 wt % niobium, with the balance being titanium.    
     
     
         40 . The article of  claim 39 , wherein the medical device is a stent, a guide wire, a dental implant, an orthodontic arch wire, an orthopedic device for bone and/or tissue, or an eyewear frame.  
     
     
         41 . An article manufactured by a method comprising: 
 forming a shape from a composition comprising titanium; and    a molybdenum equivalent weight of about 7 to about 11 wt %, wherein the weight percents are based upon the total weight of the alloy composition, wherein the composition is superelastic and/or pseudoelastic;    cold working the shape; and    solution treating the shape.    
     
     
         42 . The method of  claim 41 , wherein the solution treating is conducted at a temperature below the β transus temperature for the composition.  
     
     
         43 . The method of  claim 41 , wherein the solution treating is conducted at a temperature above the β transus temperature for the composition.  
     
     
         44 . The method of  claim 43 , wherein the shape is further cooled in air or in an inert gas.  
     
     
         45 . The method of  claim 41 , wherein the shape is further heat aged at a temperature of about 350 to about 550° C.  
     
     
         46 . The method of  claim 41 , wherein the heat ageing is conducted for a time period of 10 seconds to about 8 hours.  
     
     
         47 . An article manufactured by a method comprising: 
 cold working a wire, wherein the wire has a composition comprising titanium; and a molybdenum equivalent weight of about 7 to about 11 wt %, wherein the weight percents are based upon the total weight of the alloy composition; and wherein the molybdenum equivalent weights are determined by the equation (1)      MO   eq. =1.00Mo+0.28Nb+0.22Ta+0.67V+1.43Co+1.60Cr+0.77Cu+2.90Fe+1.54Mn+1.11Ni+0.44W−1.00Al  (1)    or the equation (2)      MO   eq. =1.00Mo+0.28Nb+0.22Ta+0.67V+1.43Co+1.60Cr+0.77Cu+2.90Fe+1.54Mn+1.11Ni+0.44W+0.25(Sn+Zr+Hf)−1.00Al  (2)    wherein Mo is molybdenum, Nb is niobium, Ta is tantalum, V is vanadium, Co is cobalt, Cr is chromium, Cu is copper, Fe is iron, Mn is manganese, Ni is nickel, W is tungsten, Al is aluminum, Sn is tin, Zr is zirconium and Hf is hafnium; wherein the aluminum can be substituted by carbon, boron, germanium and/or gallium; and wherein the respective chemical symbols represent the amounts of the respective elements in weight percent based on the total weight of the alloy composition.    
     
     
         48 . The article of  claim 47 , wherein the wire diameter is about 0.1 to about 10 millimeters.  
     
     
         49 . The article of  claim 47 , wherein the article has a martensitic structure.  
     
     
         50 . The article of  claim 47 , wherein the article has an elastic recovery of greater than or equal to about 75% of the applied change in length when the applied change in length is 2% of the original length.  
     
     
         51 . The article of  claim 47 , wherein the article has an elastic recovery of greater than or equal to about 50% of the applied change in length when the applied change in length is 4% of the original length.  
     
     
         52 . The article of  claim 47 , wherein the article is a medical device.  
     
     
         53 . The article of  claim 52 , wherein the medical device is a stent, a dental implant, a guide wire, an orthodontic arch wire, an orthopedic device used in bone and/or tissue, or an eyewear frame.  
     
     
         54 . The article of  claim 47 , wherein the article is used as a file or a drill in dental applications.  
     
     
         55 . The article of  claim 47 , wherein the article comprises an insert for a golf club head and further wherein the insert is welded or brazed to the golf club head.