Fine grain niobium sheet via ingot metallurgy

Abstract

A method of making an alloy of niobium that includes: A) forming a blend comprising niobium powder and a powder of a metal selected from the group consisting of yttrium, aluminum, hafnium, titanium, zirconium, thorium, lanthanum and cerium and pressing the blend to form pressed blend; B) attaching the pressed blend to an electrode comprising niobium; C) melting the electrode and pressed blend under vacuum arc remelting conditions, such that the blend mixes with the melted electrode; D) cooling the melted electrode to form an alloy ingot; and E) applying thermo-mechanical processing steps to the alloy ingot to form a wrought product. The method provides a fully recrystallized niobium wrought product with a grain size finer that ASTM 5, that can be used to make deep drawn cups and sputtering targets.

1 . A method of making an alloy of niobium comprising: 
 A) forming a blend comprising niobium powder and a powder of a metal selected from the group consisting of yttrium, aluminum, hafnium, titanium, zirconium, thorium, lanthanum and cerium and pressing the blend to form pressed blend;    B) attaching the pressed blend to an electrode comprising niobium;    C) melting the electrode and pressed blend under vacuum arc remelting conditions, such that the blend mixes with the melted electrode;    D) cooling the melted electrode to form an alloy ingot; and    E) applying thermo-mechanical processing steps to the alloy ingot to form a wrought product.    
     
     
         2 . The method according to  claim 1 , wherein the wrought product in E) has a fine and uniform ASTM grain size of from 5 to 10.  
     
     
         3 . The method according to  claim 1 , wherein the metal is present in A) at from 0.1 to 100 ppm based on total niobium in the wrought product.  
     
     
         4 . The method according to  claim 1 , wherein the thermo-mechanical processing steps in E) comprise: 
 i) forging the alloy ingot to form a wrought product; and    ii) annealing the wrought product at a temperature of from 950 to 1150° C.    
     
     
         5 . The method according to  claim 4 , wherein the wrought product is selected from the group consisting of foils, sheets, plates, tubes, and rods.  
     
     
         6 . The method according to  claim 4 , wherein the annealing in i) results in at least 75% recrystallization.  
     
     
         7 . The method according to  claim 1 , wherein the thermo-mechanical processing steps in E) comprise: 
 I) rolling the wrought product to an intermediate thickness;    II) annealing the wrought product of 1) at a temperature of from 950 to 1150° C. for a period of from 30 minutes to 180 minutes;    III) rolling the wrought product of 11); and    IV) annealing the wrought product of II) at a temperature of from 950 to 1150° C. for a period of from 30 minutes to 180 minutes and then cooling the wrought product to room temperature.    
     
     
         8 . The method according to  claim 6 , wherein the wrought product is selected from the group consisting of foils, sheets, plates, tubes, and rods.  
     
     
         9 . The method according to  claim 7 , wherein the annealing in 11) and IV) result in at least 75% recrystallization.  
     
     
         10 . A niobium containing wrought product obtained according to the method of  claim 1 .  
     
     
         11 . The wrought product according to  claim 10 , wherein the wrought product is selected from the group consisting of a foil, a sheet, a plate, a tube, and a rod.  
     
     
         12 . Deep drawn cups prepared from the wrought product according to  claim 10 .  
     
     
         13 . Sputtering targets prepared from the wrought product according to  claim 10 .  
     
     
         14 . A method of making an alloy of niobium comprising: 
 a) melting niobium to form a melt;    b) adding 0.1 to 60 ppm of a metal selected from the group consisting of yttrium, aluminum, hafnium, titanium, zirconium, thorium, lanthanum and cerium, based on the niobium in the melt;    c) cooling the melt to form an alloy ingot;    d) applying thermo-mechanical processing steps to the alloy ingot to form a wrought product.    
     
     
         15 . The method according to  claim 14 , wherein the wrought product has a fine and uniform ASTM grain size of from 5 to 10.  
     
     
         16 . The method according to  claim 14 , wherein the metal is present in b) at from 0.1 to 100 ppm based on total niobium.  
     
     
         17 . The method according to  claim 14 , wherein the thermo-mechanical processing steps in d) comprise: 
 i) forging the alloy ingot to form a wrought product; and    ii) annealing the wrought product at a temperature of from 950 to 1150° C.    
     
     
         18 . The method according to  claim 17 , wherein the wrought product is selected from the group consisting of foils, sheets, plates, tubes, and rods.  
     
     
         19 . The method according to  claim 17 , wherein the annealing in i) results in at least 75% recrystallization.  
     
     
         20 . The method according to  claim 14 , wherein the thermo-mechanical processing steps in d) comprise: 
 I) rolling the wrought product to an intermediate thickness;    II) annealing the wrought product of 1) at a temperature of from 950 to 1150° C. for a period of from 30 minutes to 180 minutes;    III) rolling the wrought product of 11); and    IV) annealing the wrought product of II) at a temperature of from 950 to 1150° C. for a period of from 30 minutes to 180 minutes and then cooling the wrought product to room temperature.    
     
     
         21 . The method according to  claim 20 , wherein the wrought product is selected from the group consisting of foils, sheets, plates, tubes, and rods.  
     
     
         22 . The method according to  claim 21 , wherein the annealing in 11) and IV) result in at least 75% recrystallization.  
     
     
         23 . A niobium containing wrought product obtained according to the method of  claim 14 .  
     
     
         24 . The wrought product according to  claim 23 , wherein the wrought product is selected from the group consisting of a foil, a sheet, a plate, a tube, and a rod.  
     
     
         25 . Deep drawn cups prepared from the wrought product according to  claim 23 .  
     
     
         26 . Sputtering targets prepared from the wrought product according to  claim 24.