US2024287665A1PendingUtilityA1

Aluminum-copper-lithium alloy products

74
Assignee: CONSTELLIUM ISSOIREPriority: Apr 10, 2017Filed: Apr 29, 2024Published: Aug 29, 2024
Est. expiryApr 10, 2037(~10.7 yrs left)· nominal 20-yr term from priority
Inventors:Juliette Chevy
C22C 21/18C22C 21/16C22F 1/057C22C 21/12
74
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Claims

Abstract

The invention relates to a product made of an aluminium-based alloy comprising, by wt. %, Cu: 2.5-3.4; Li: 1.6-2.2; Mg: 0.4-0.9; Mn: 0.2-0.6, Zr: 0.08-0.18; Zn: <0.4; Ag: <0.15; Fe+Si: S 0.20; at least one element selected from Ti, Se, Cr, Hf and V, the content of the element, if selected, being: Ti: 0.01-0.15; Se: 0.01-0.15; Cr: 0.01-0.3; Hf: 0.01-0.5; V: 0.01-0.3; other elements: S 0.05 each and: S 0.15 in total; the remainder being aluminium. The invention also relates to a method for manufacturing an aluminum alloy-based, extruded, rolled and/or forged product, and a structural element incorporating at least one product as described above.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
         1 . A method for manufacturing an extruded, rolled and/or forged product containing aluminum alloy, comprising:
 a) producing a bath of liquid metal comprising, in percentage by weight, Cu: 2.5-3.4; Li: 1.6-2.2; Mg: 0.4-0.9; Mn: 0.2-0.6; Zr: 0.08-0.18; Zn: <0.4; Ag: <0.15; Fe+Si≤0.20; at least one element selected from the group consisting of Ti, Sc, Cr, Hf and V, the concentration of said element, if chosen, being Ti: 0.01-0.15; Sc: 0.01-0.15; Cr: 0.01-0.3; Hf: 0.01-0.5; V: 0.01-0.3; other elements≤0.05 each and ≤0.15 in total, the rest aluminum;   b) casting an unwrought product from said bath of liquid metal;   c) homogenization said unwrought product;   d) hot and, optionally, cold working of the unwrought product into an extruded, rolled and/or forged product;   e) solution heat treatment and quenching of said product;   f) stretching in a controlled manner of said product with a permanent set from 1 to 15%;   g) aging of said extruded product by heating to 140 to 170° C. for 5 to 70 hours in such a way that said product has a conventional elastic limit measured at 0.2% of elongation in the direction L, R p0.2  (L), of at least 510 MPa and a toughness K Q  (L−T), in the direction L−T, of at least 21 Mpa √{square root over (m)} and such that K Q  (L−T)>−0.2667*R p0.2  (L)+169.   
     
     
         2 . The method according to  claim 1 , wherein the temperature of homogenizing is between 520° C. and 530° C. and the treatment time is between 6 and 15 hours. 
     
     
         3 . The method according to  claim 1 , wherein the aging is carried out at a temperature between 150 to 165° C. for a time with an equivalent t i  at 160° C. between 15 and 28 h, t i  being defined by the formula: 
       
         
           
             
               
                 t 
                 i 
               
               = 
               
                 
                   ∫ 
                   
                     
                       exp 
                       ⁡ 
                       ( 
                       
                         
                           - 
                           16400 
                         
                         / 
                         T 
                       
                       ) 
                     
                     ⁢ 
                         
                     dt 
                   
                 
                 
                   exp 
                   ⁡ 
                   ( 
                   
                     
                       - 
                       1 
                     
                     ⁢ 
                     6400 
                     / 
                     
                       T 
                       ref 
                     
                   
                   ) 
                 
               
             
           
         
         where T (in Kelvin) is the instantaneous temperature of treatment of the metal, which changes over the time t (in hours), and T ref  is a reference temperature set to 433K. 
       
     
     
         4 . The method according to  claim 1 , wherein step f) comprises stretching in a controlled manner of said product with a permanent set from 2 to 4%. 
     
     
         5 . The method according to  claim 1 , wherein the aging is carried out at a temperature between 150 to 165° C. for a time with an equivalent t i  at 160° C. between 20 and 27 h, t i  being defined by the formula: 
       
         
           
             
               
                 t 
                 i 
               
               = 
               
                 
                   ∫ 
                   
                     
                       exp 
                       ⁡ 
                       ( 
                       
                         
                           - 
                           16400 
                         
                         / 
                         T 
                       
                       ) 
                     
                     ⁢ 
                         
                     dt 
                   
                 
                 
                   exp 
                   ⁡ 
                   ( 
                   
                     
                       - 
                       1 
                     
                     ⁢ 
                     6400 
                     / 
                     
                       T 
                       ref 
                     
                   
                   ) 
                 
               
             
           
         
         where T (in Kelvin) is the instantaneous temperature of treatment of the metal, which changes over the time t (in hours), and T ref  is a reference temperature set to 433K. 
       
     
     
         6 . The method according to  claim 1 , wherein the concentration of copper is from 2.9 to 3.1% by weight. 
     
     
         7 . The method according to  claim 1 , wherein the concentration of lithium is from 1.65 to 1.75% by weight. 
     
     
         8 . The method according to  claim 1 , wherein the concentration of manganese is from 0.4 to 0.6% by weight. 
     
     
         9 . The method according to  claim 1 , wherein the concentration of zirconium is from 0.14 to 0.15% by weight. 
     
     
         10 . The method according to  claim 1 , wherein the concentration of magnesium is from 0.5 to 0.8% by weight. 
     
     
         11 . The method according to  claim 1 , wherein the concentration of zinc is from 0.05 to 0.35% by weight. 
     
     
         12 . The method according to  claim 1 , wherein the concentration of silver is less than 0.10% by weight. 
     
     
         13 . The method according to  claim 1 , wherein the concentrations of iron and silicon are each at most 0.08% by weight. 
     
     
         14 . The method according to  claim 1 , wherein the concentration of the at least one element, if chosen, being Ti: 0.01-0.05; Sc: 0.02-0.1; Cr: 0.02-0.1; Hf: 0.02-0.1; V: 0.01-0.05. 
     
     
         15 . The method according to  claim 1 , wherein the bath of liquid metal comprises, in % by weight,
 Cu: 2.8-3.2;   Li: 1.65-1.8;   Mg: 0.5-0.8;   Mn: 0.3-0.6;   Zr: 0.12-0.16;   Zn: 0.05-0.4;   Ag: <0.1;   Fe+Si≤0.20;   At least one element selected from the group consisting of Ti, Sc, Cr, Hf and V, the concentration of the element, if chosen, being in weight %:   Ti: 0.01-0.05;   Sc: 0.02-0.1;   Cr: 0.02-0.1;   Hf: 0.02-0.1;   V: 0.01-0.05;   other elements≤0.05 each and ≤0.15 in total, the rest aluminum.   
     
     
         16 . The method according to  claim 1 , wherein the solution heat treatment is carried out at a temperature between 490° C. and 550° C. for 15 min to 8 h. 
     
     
         17 . The method according to  claim 1 , wherein the permanent set is from 2 to 4%.

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