8000-series aluminum alloy

Abstract

An 8000-series aluminum alloy, useful to form wires, including a rare-earth element. The alloy exhibits improved creep resistance and stress relaxation resistance, as compared to the same alloy that is substantially free of the rare-earth element, while the electrical conductivity of the alloy is substantially unaffected by the addition of the rare-earth element.

What is claimed is: 
     
         1 . An 8000-series aluminum alloy comprising:
 aluminum;   about 0.30% to about 0.80%, by weight, iron;   about 0.10% to about 0.30%, by weight, copper; and   about 0.001% to about 0.10/%, by weight, of a rare-earth element (REE) selected from one or both of erbium and ytterbium.   
     
     
         2 . The 8000-series aluminum alloy of  claim 1 , wherein the alloy comprises about 0.005% to about 0.1%, by weight, of the REE. 
     
     
         3 . The 8000-series aluminum alloy of  claim 1 , wherein the alloy comprises about 0.01% to about 0.03%, by weight, of the REE. 
     
     
         4 . The 8000-series aluminum alloy of  claim 1 , the alloy further comprising:
 about 0.02%, by weight, silicon; and   wherein the alloy comprises about 0.44%, by weight, iron, and about 0.17%, by weight, copper,   wherein the REE comprises about 0.01% to about 0.03%, by weight, erbium; and   wherein the alloy is an AA8030 aluminum alloy.   
     
     
         5 . The 8000-series aluminum alloy of  claim 4 , wherein the alloy exhibits one or more of:
 i) a tensile creep rate of about 1*10 −5  s −1  to about 2*10 −8  s −1  when measured in accordance with ASTM E139 at 100° C. with 70 MPa of applied stress;   ii) a tensile strength relaxation time, to reach about 85% of 75 MPa initial tensile stress, of about 1,000 seconds or greater when measured in accordance with ASTM E328 at 25° C.; and   iii) an electrical conductivity of about 60.5% or greater when measured in accordance with the International Annealed Copper Standard (“IACS”).   
     
     
         6 . The 8000-series aluminum alloy of  claim 4 , wherein the alloy exhibits:
 i) a tensile creep rate of about 1*10 −5  s −1  to about 2*10 −8  s −1  when measured in accordance to ASTM E139 at 100° C. with 70 MPa of applied stress;   ii) a tensile strength relaxation time, to reach about 85% of 75 MPa initial tensile stress, of about 1,000 seconds or greater when measured in accordance to ASTM E328 at 25° C.; and   iii) an electrical conductivity of about 60.5% or greater when measured in accordance with the International Annealed Copper Standard (“IACS”).   
     
     
         7 . The 8000-series aluminum alloy of  claim 4 , wherein the alloy exhibits an electrical conductivity at least as great as an electrical conductivity of an AA8030 aluminum alloy substantially free of the REE. 
     
     
         8 . The 8000-series aluminum alloy of  claim 4 , wherein the alloy exhibits an ultimate tensile strength of at least about 99 MPa when measured in accordance with ASTM B941. 
     
     
         9 . The 8000-series aluminum alloy of  claim 4 , wherein the alloy exhibits an elongation at break at least as great as an elongation at break of an AA8030 aluminum alloy substantially free of the REE. 
     
     
         10 . The 8000-series aluminum alloy of  claim 1 , the alloy further comprising:
 about 0.03%, by weight, magnesium; and   about 0.02%, by weight, silicon; and   wherein the alloy comprises about 0.55%, by weight, iron, and about 0.17%, by weight, copper,   wherein the REE comprises about 0.01% to about 0.03%, by weight, erbium; and   wherein the alloy is an AA8017 aluminum alloy.   
     
     
         11 . The 8000-series aluminum alloy of  claim 10 , wherein the alloy exhibits one or more of:
 i) a tensile creep rate of about 1*10 −5  s −1  to about 2*10 −8  s −1  when measured in accordance with ASTM E139 at 100° C. with 70 MPa of applied stress;   ii) a tensile strength relaxation time, to reach about 85% of 75 MPa initial tensile stress, of about 2,000 seconds or greater when measured in accordance with ASTM E328 at 25° C.; and   iii) an electrical conductivity of about 60.5% or greater when measured in accordance with the International Annealed Copper Standard (“IACS”).   
     
     
         12 . The 8000-series aluminum alloy of  claim 10 , wherein the alloy exhibits:
 i) a tensile creep rate of about 1*10 −5  s −1  to about 2*10 −8  s −1  when measured in accordance with ASTM E139 at 100° C. with 70 MPa of applied stress;   ii) a tensile strength relaxation time, to reach about 85% of 75 MPa initial tensile stress, of about 2,000 seconds or greater when measured in accordance with ASTM E328 at 25° C.; and   iii) an electrical conductivity of about 60.5% or greater when measured in accordance with the International Annealed Copper Standard (“IACS”).   
     
     
         13 . The 8000-series aluminum alloy of  claim 10 , wherein the alloy exhibits an electrical conductivity at least as great as an electrical conductivity of an AA8017 aluminum alloy substantially free of the REE. 
     
     
         14 . The 8000-series aluminum alloy of  claim 10 , wherein the alloy exhibits an ultimate tensile strength of at least about 114 MPa when measured in accordance with ASTM B941. 
     
     
         15 . An 8000-series aluminum alloy comprising:
 aluminum;   about 0.30% to about 0.80%, by weight, iron;   about 0.01% to about 0.20%, by weight, silicon; and   about 0.001% to about 0.1%, by weight, of a rare-earth element (REE) selected from one or both of erbium and ytterbium.   
     
     
         16 . The 8000-series aluminum alloy of  claim 15 , wherein the alloy comprises about 0.005% to about 0.1%, by weight, of the REE. 
     
     
         17 . The 8000-series aluminum alloy of  claim 15 , wherein the alloy comprises about 0.01% to about 0.05%, by weight, of the REE. 
     
     
         18 . The 8000-series aluminum alloy of  claim 15 ,
 wherein the alloy comprises about 0.55%, by weight, iron, and about 0.04%, by weight, silicon;   wherein the REE comprises about 0.005% to about 0.05%, by weight, erbium; and   wherein the alloy is an AA8176 aluminum alloy.   
     
     
         19 . The 8000-series aluminum alloy of  claim 18 , wherein the alloy exhibits one or more of:
 i) a tensile creep rate of less than about 2*10 −7  s −1  when measured in accordance with ASTM E139 at 100° C. with 70 MPa of applied stress;   ii) a tensile strength relaxation time, to reach about 85% of 75 MPa initial tensile stress, of about 2,000 seconds or greater when measured in accordance with ASTM E328 at 25° C.; and   iii) an electrical conductivity of about 60.0% or greater when measured in accordance with the International Annealed Copper Standard (“IACS”).   
     
     
         20 . The 8000-series aluminum alloy of  claim 18 , wherein the alloy exhibits:
 i) a tensile creep rate of less than about 2*10 −7  s −1  when measured in accordance with ASTM E139 at 100° C. with 70 MPa of applied stress;   ii) a tensile strength relaxation time, to reach about 85% of 75 MPa initial tensile stress, of about 2,000 seconds or greater when measured in accordance with ASTM E328 at 25° C.; and   iii) an electrical conductivity of about 60.0% or greater when measured in accordance with the International Annealed Copper Standard (“IACS”).   
     
     
         21 . The 8000-series aluminum alloy of  claim 18 , wherein the alloy exhibits an ultimate tensile strength of at least about 104 MPa when measured in accordance with ASTM B941. 
     
     
         22 . A method of making an 8000-series aluminum alloy, the method comprising:
 making a melt comprising the following constituents:
 a) each of the elements that is both required by and in a proportion permitted by a definition of a standard aluminum alloy selected from a group consisting of AA8030, AA8176, and AA 8017; and 
 b) about 0.001% to about 0.1%, by weight, of a rare-earth element (REE), the REE consisting of one or both of erbium and ytterbium; and 
   solidifying the melt, and cooling a resulting solid piece.   
     
     
         23 . The method of  claim 22 , wherein the REE comprises about 0.005% to about 0.05%, by weight, of erbium.