High strength and thermally stable 5000-series aluminum alloys

Abstract

The present disclosure relates to a new family of 5000-series alloys that have high strength and can resist strength softening during stabilization and/or annealing treatment, after cold rolling, working or strain hardening, which are highly advantageous for food and beverage and automotive industries.

1 . An aluminum alloy comprising:
 about 2.5 to about 6.2% by weight magnesium;   about 0.01 to about 1.8% by weight manganese;   about 0.01 to about 0.6% by weight iron;   about 0.01 to about 0.5% by weight silicon;   about 0.01 to about 1% by weight copper; and   aluminum as the remainder.   
     
     
         2 . The aluminum alloy of  claim 1 , further comprising:
 about 0.1 to about 0.5% by weight zirconium; and   about 0.01 to about 0.2% by weight tin.   
     
     
         3 . The aluminum alloy of  claim 2 , comprising about 4.5% by weight magnesium, about 0.25% by weight manganese, about 0.2% by weight iron, about 0.1% by weight silicon, about 0.3% by weight zirconium, about 0.1% by weight tin, about 0.15%, about 0.3%, or about 0.6% by weight copper, and aluminum as the remainder. 
     
     
         4 - 5 . (canceled) 
     
     
         6 . The aluminum alloy of  claim 1 , wherein the alloy is essentially free of scandium. 
     
     
         7 . The aluminum alloy of  claim 2 , wherein the alloy possesses a yield strength of at least 400 MPa, a tensile strength of at least 450 MPa, and an elongation of at least 5% in the hard-temper condition. 
     
     
         8 . The aluminum alloy of  claim 2  wherein after forming or stretching, the alloy resists strength softening during paint-bake cycle. 
     
     
         9 . The aluminum alloy of  claim 2  wherein the alloy possesses a yield strength of at least 170 MPa after forming and stretching, following by a paint-bake cycle. 
     
     
         10 . The aluminum alloy of  claim 1 , wherein the alloy comprises an Al3Zr nanoscale precipitate, wherein the nanoscale precipitate has an average diameter of about 20 nm or less and has an L1 2  structure in an a-Al face centered cubic matrix, and wherein the average number density of the nanoscale precipitate is about 10 21  m -3  or more. 
     
     
         11 . The aluminum alloy of  claim 1 , wherein the alloy comprises Cu-containing phases. 
     
     
         12 . The aluminum alloy of  claim 11 , wherein the Cu-containing phases enhance thermal stability during moderate aging treatment, after cold rolling, forming or stretching (e.g. stabilization treatment and/or a paint-bake cycle). 
     
     
         13 . The aluminum alloy of  claim 11  wherein the Cu-containing phases comprise A12C U Mg precipitates and/or S′phase. 
     
     
         14 . The aluminum alloy of  claim 13 , wherein the formation of A12C U Mg precipitates results in an increase in tensile strength compared to a reference AA5182 alloy without intentionally added copper. 
     
     
         15 . A method for manufacturing a component from the aluminum alloy of  claim 1  the method comprising:
 a) melting the alloy at a temperature of about 700° C. to about 900° C.; 
 b) casting the alloy into casting molds; 
 c) using a cooling medium to cool the cast ingot; and 
 d) hot rolling the cast ingot into plates or sheet at temperatures between 300° C. and 600° C. 
 
     
     
         16 . The method of  claim 15 , wherein to generate a hard-temper condition, the method further comprises:
 e) heat aging the plate or sheet at a temperature of about 350° C. to about 550° C. for a time of about 2 hours to about 48 hours;   f) cold rolling the hot rolled and heat treated sheet or plate to form thin sheet or foil products; and   g) stabilizing heat treatment and/or coat cure treatment at temperatures between 100° C. and 250° C. for 1 min to 8 h of the sheet products.   
     
     
         17 . The method of  claim 15 , wherein to generate a soft-temper condition, the method further comprises:
 e) cold rolling the hot rolled sheet or plate to form thin sheet or foil products; and   f) heat aging the sheet or foil at a temperature about 300° C. to about 550° C. for a time of about 2 h to about 48 h.   
     
     
         18 . The method of  claim 16 , wherein after cold rolling, the alloy resists strength softening during stabilization treatment and shows improved ductility. 
     
     
         19 . The method of  claim 16  wherein after cold rolling, the alloy resists strength softening during coat cure treatment and shows improved ductility. 
     
     
         20 - 21 . (canceled) 
     
     
         22 . The aluminum alloy of  claim 1 , comprising about 4.5% by weight magnesium, about 0.25% by weight manganese, about 0.2% by weight iron, about 0.1% by weight silicon, about 0.15%, about 0.3%, about 0.45%, or about 0.6% by weight copper, and aluminum as the remainder. 
     
     
         23 - 25 . (canceled) 
     
     
         26 . The aluminum alloy of  claim 1 , wherein the alloy possesses a yield strength of at least 370 MPa, a tensile strength of at least 430 MPa, and an elongation of at least 5% in a hard-temper condition. 
     
     
         27 . The aluminum alloy of  claim 1  wherein after cold rolling, the alloy resists strength softening during stabilization treatment, and shows improved ductility. 
     
     
         28 . The aluminum alloy of  claim 1 , wherein after cold rolling, the alloy resists strength softening during coat cure treatment, and shows improved ductility. 
     
     
         29 - 39 . (canceled)