High-purity titanium-nickel alloys with shape memory

Abstract

The invention includes an alloy containing equivalent amounts of nickel and titanium. The alloy has shape memory and a metallic purity of at least about 99.995%, and comprises less than about 200 ppm of gases. The invention also includes an alloy comprising titanium and nickel where the titanium and nickel amounts are non-equivalent. The alloy has shape memory and has a metallic purity of at least 99.995%, and contains less than about 200 ppm of gases. The invention further includes a method of producing a shape memory alloy. Titanium is provided having a metallic purity of at least 99.999% and nickel is provided having a metallic purity of at least 99.99%. The titanium and nickel are combined utilizing at least one melting event independently selected from e-beam melting, vacuum arc melting, vacuum induction melting, induction skull melting and plasma melting.

1 . An alloy comprising: 
 a nickel content; and    a titanium content atomically equivalent to the nickel content, the alloy having shape memory and having a metallic purity of at least about 99.995%, by weight and comprising less than about 200 ppm of gases, by weight.    
   
   
       2 . The alloy of  claim 1  wherein the alloy is a binary alloy.  
   
   
       3 . The alloy of  claim 1  wherein the alloy further comprises at least one additional metal.  
   
   
       4 . The alloy of  claim 3  wherein the at least one additional metal is selected from the group consisting of Nb, H, Ta, Pt, Pd, Au, Zr, Fe, V, Mo, W, Ru, Cr, and Cu.  
   
   
       5 . (canceled)  
   
   
       6 . The alloy of  claim 3  wherein a total amount of the at least one additional metal present in the alloy is exceeded by a combined amount of Ni and Ti.  
   
   
       7 . The alloy of  claim 1  wherein the metallic purity of the alloy is at least 99.998%, by weight.  
   
   
       8 . The alloy of  claim 1  comprising less than or equal to 1 ppm each (by weight) of metallic impurities selected from the group consisting of Al, Co, and Zr.  
   
   
       9 . The alloy of  claim 1  comprising less than or equal to 50 ppm Fe, by weight.  
   
   
       10 . The alloy of  claim 1  comprising less than or equal to 10 ppm W, by weight.  
   
   
       11 . The alloy of  claim 1  comprising less than or equal to 5 ppm Cr, by weight.  
   
   
       12 . The alloy of  claim 1  comprising less than or equal to 0.25 ppm each (by weight) of metallic impurities selected from the group consisting of V, Si, B, Hf, Mg, Mn, P, and Re.  
   
   
       13 . The alloy of  claim 1  comprising less than or equal to 0.1 ppm each (by weight) of metallic impurities selected from the group consisting of B, Hf, Mg, Mn, P, and Re.  
   
   
       14 . The alloy of  claim 1  comprising less than or equal to 100 ppm O, by weight.  
   
   
       15 . The alloy of  claim 1  comprising less than or equal to 50 ppm C, by weight.  
   
   
       16 . The alloy of  claim 1  comprising less than or equal to 3 ppm N, by weight.  
   
   
       17 . The alloy of  claim 1  comprising less than or equal to 5 ppm S, by weight.  
   
   
       18 . The alloy of  claim 1  comprising less than or equal to 5 ppm H, by weight.  
   
   
       19 . An alloy comprising: 
 titanium; and    nickel, an atomic amount of nickel present in the alloy exceeding the atomic amount of titanium present in the alloy, the alloy having shape memory and having a metallic purity of at least about 99.995%, by weight and comprising less than about 200 ppm of gases, by weight.    
   
   
       20 . The alloy of  claim 19  wherein the amount of nickel exceeds the amount of titanium by from greater than 0 at % to about 1 at %.  
   
   
       21 . The alloy of  claim 19  wherein the alloy is a binary alloy.  
   
   
       22 . The alloy of  claim 19  wherein the alloy further comprises at least one additional metal.  
   
   
       23 . The alloy of  claim 22  wherein the at least one additional metal is selected from the group consisting of Nb, Hf, Ta, Pt, Pd, Au, Zr, Fe, V, Mo, W, Ru, Cr, and Cu.  
   
   
       24 . (canceled)  
   
   
       25 . The alloy of  claim 22  wherein a total amount of the at least one additional metal present in the alloy is exceeded by a combined amount of Ni and Ti.  
   
   
       26 . The alloy of  claim 19  wherein the metallic purity of the alloy is at least 99.998%, by weight.  
   
   
       27 . The alloy of  claim 19  comprising less than or equal to 1 ppm each (by weight) of metallic impurities selected from the group consisting of Al, Co, and Zr.  
   
   
       28 . The alloy of  claim 19  comprising less than or equal to 50 ppm Fe, by weight.  
   
   
       29 . The alloy of  claim 19  comprising less than or equal to 10 ppm W, by weight.  
   
   
       30 . The alloy of  claim 19  comprising less than or equal to 5 ppm Cr, by weight.  
   
   
       31 . The alloy of  claim 19  comprising less than or equal to 0.25 ppm (by weight) each of metallic impurities selected from the group consisting of V, Si, B, Hf, Mg, Mn, P, and Re.  
   
   
       32 . The alloy of  claim 19  comprising less than or equal to 0.1 ppm (by weight) each of metallic impurities selected from the group consisting of B, Hf, Mg, Mn, P, and Re.  
   
   
       33 . The alloy of  claim 19  comprising less than or equal to 100 ppm O, by weight.  
   
   
       34 . The alloy of  claim 19  comprising less than or equal to 50 ppm C, by weight.  
   
   
       35 . The alloy of  claim 19  comprising less than or equal to 3 ppm N, by weight.  
   
   
       36 . The alloy of  claim 19  comprising less than or equal to 5 ppm S, by weight.  
   
   
       37 . The alloy of  claim 19  comprising less than or equal to 5 ppm H, by weight.  
   
   
       38 . An alloy comprising: 
 nickel; and    titanium, an atomic amount of titanium present in the alloy exceeding the atomic amount of nickel present in the alloy, the alloy having shape memory and having a metallic purity of at least about 99.995%, by weight and comprising less than about 200 ppm of gases, by weight.    
   
   
       39 . The alloy of  claim 38  wherein the amount of titanium exceeds the amount of nickel by from greater than 0 at % to about 1 at %.  
   
   
       40 . The alloy of  claim 38  wherein the alloy is a binary alloy.  
   
   
       41 . The alloy of  claim 38  wherein the alloy further comprises at least one additional metal.  
   
   
       42 . The alloy of  claim 41  wherein the at least one additional metal is selected from the group consisting of Nb, Hf, Ta, Pt, Pd, Au, Zr, Fe, V, Mo, W, Ru, Cr, and Cu.  
   
   
       43 . (canceled)  
   
   
       44 . The alloy of  claim 41  wherein a total amount of the at least one additional metal present in the alloy is exceeded by a combined amount of Ni and Ti.  
   
   
       45 . The alloy of  claim 38  wherein the metallic purity of the alloy is at least 99.998%, by weight.  
   
   
       46 . The alloy of  claim 38  comprising less than or equal to 1 ppm each (by weight) of metallic impurities selected from the group consisting of Al, Co, and Zr.  
   
   
       47 . The alloy of  claim 38  comprising less than or equal to 50 ppm Fe, by weight.  
   
   
       48 . The alloy of  claim 38  comprising less than or equal to 10 ppm W, by weight.  
   
   
       49 . The alloy of  claim 38  comprising less than or equal to 5 ppm Cr, by weight.  
   
   
       50 . The alloy of  claim 38  comprising less than or equal to 0.25 ppm (by weight) each of metallic impurities selected from the group consisting of V, Si, B, Hf, Mg, Mn, P, and Re.  
   
   
       51 . The alloy of  claim 38  comprising less than or equal to 0.1 ppm (by weight) each of metallic impurities selected from the group consisting of B, Hf, Mg, Mn, P, and Re.  
   
   
       52 . The alloy of  claim 38  comprising less than or equal to 100 ppm O, by weight.  
   
   
       53 . The alloy of  claim 38  comprising less than or equal to 50 ppm C, by weight.  
   
   
       54 . The alloy of  claim 38  comprising less than or equal to 3 ppm N, by weight.  
   
   
       55 . The alloy of  claim 38  comprising less than or equal to 5 ppm S, by weight.  
   
   
       56 . The alloy of  claim 38  comprising less than or equal to 5 ppm H, by weight.  
   
   
       57 - 65 . (canceled)