High strength and low quench sensitive 7xxx series aluminum alloys and methods of making

Abstract

Described are methods of making an aluminum alloy product. The method includes heating a rolled aluminum alloy product to a first temperature of from 400° C. to 525° C. The rolled aluminum alloy product may include a 7xxx series aluminum alloy. The method also includes maintaining the rolled aluminum alloy product at the first temperature or within 10° C. of the first temperature for a time duration of from 15 seconds to 30 minutes. The method also includes quenching the rolled aluminum alloy product at a quench rate from 0.5° C./s to 125° C./s thereby generating a heat-treated aluminum alloy product. The heat-treated aluminum alloy product exhibits a strain ratio of from 0.3 to 0.8. The strain ratio is determined according to an ASTM G129 and/or ASTM G139 standard test method.

1 . A method comprising:
 heating a rolled aluminum alloy product to a first temperature of from 400° C. to 525° C. wherein the rolled aluminum alloy product comprises a 7xxx series aluminum alloy comprising:   from 4.00 wt. % to 15.00 wt. % Zn,   from 0.10 wt. % to 3.50 wt. % Cu,   from 1.00 wt. % to 4.00 wt. % Mg,   from 0.05 wt. % to 0.50 wt. % Fe,   from 0.05 wt. % to 0.30 wt. % Si,   from 0.05 wt. % to 0.25 wt. % Zr,   up to 0.25 wt. % Mn,   up to 0.20 wt. % Cr,   up to 0.15 wt. % Ti, and   Al;   maintaining the rolled aluminum alloy product at the first temperature or within 10° C. of the first temperature for a time duration of from 15 seconds to 30 minutes; and   quenching the rolled aluminum alloy product at a quench rate from 0.5° C./s to 125° C./s thereby generating a heat-treated aluminum alloy product, wherein the heat-treated aluminum alloy product exhibits a strain ratio of from 0.3 to 0.8, and wherein the strain ratio is determined according to an ASTM G129 standard test method.   
     
     
         2 . The method of  claim 1 , wherein the rolled aluminum alloy product is quenched until the rolled aluminum alloy product reaches a second temperature of from 10° C. to 100° C. 
     
     
         3 . The method of  claim 2 , wherein quenching comprises a first quenching at a first quench rate to an intermediate temperature, a second quenching at a second quench rate to the second temperature, wherein the second quench rate is greater than the first quench rate. 
     
     
         4 . The method of  claim 1 , wherein the quench rate is from 5° C./s to 125° C./s. 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1 , wherein the rolled aluminum alloy product comprises:
 from 4.00 wt. % to 15.00 wt. % Zn,   from 0.20 wt. % to 2.60 wt. % Cu,   from 1.40 wt. % to 2.80 wt. % Mg,   from 0.10 wt. % to 0.35 wt. % Fe,   from 0.05 wt. % to 0.20 wt. % Si,   from 0.05 wt. % to 0.15 wt. % Zr,   from 0.01 wt. % to 0.05 wt. % Mn,   from 0.01 wt. % to 0.05 wt. % Cr,   from 0.001 wt. % to 0.05 wt. % Ti, and   Al.   
     
     
         7 . The method of  claim 1 , wherein the rolled aluminum alloy product comprises:
 from 4.00 wt. % to 15.00 wt. % Zn,   from 0.30 wt. % to 2.50 wt. % Cu,   from 1.60 wt. % to 2.60 wt. % Mg,   from 0.10 wt. % to 0.25 wt. % Fe,   from 0.07 wt. % to 0.15 wt. % Si,   from 0.09 wt. % to 0.15 wt. % Zr,   from 0.02 wt. % to 0.05 wt. % Mn,   from 0.03 wt. % to 0.05 wt. % Cr,   from 0.003 wt. % to 0.035 wt. % Ti, and   Al.   
     
     
         8 . The method of  claim 1 , wherein the rolled aluminum alloy product comprises:
 from 4.00 wt. % to 15.00 wt. % Zn,   from 0.20 wt. % to 2.10 wt. % Cu,   from 2.20 wt. % to 2.40 wt. % Mg,   from 0.18 wt. % to 0.23 wt. % Fe,   from 0.09 wt. % to 0.12 wt. % Si,   from 0.05 wt. % to 0.15 wt. % Zr,   from 0.04 wt. % to 0.09 wt. % Mn,   from 0.03 wt. % to 0.09 wt. % Cr,   from 0.01 wt. % to 0.02 wt. % Ti,   up to 0.15 wt. % of impurities, and   Al.   
     
     
         9 . The method of  claim 1 , wherein the rolled aluminum alloy product further comprises up to 0.20 wt. % of one or more of Mo, Nb, Be, B, Co, Sn, Sr, V, In, Hf, Ag, Sc and Ni. 
     
     
         10 . The method of  claim 1 , wherein the heat-treated aluminum alloy product exhibits a corrosion depth of from 5 μm to 300 μm as determined according to an ASTM G110 standard test method. 
     
     
         11 . The method of  claim 10 , wherein corrosion occurring within the corrosion depth comprises at least one of pitting corrosion or intergranular corrosion. 
     
     
         12 . The method of  claim 11 , wherein the corrosion comprises intergranular corrosion when the quench rate is 50° C./s or less. 
     
     
         13 . The method of  claim 11 , wherein the corrosion does not include intergranular corrosion when the quench rate is greater than 5° C./s. 
     
     
         14 . The method of  claim 10 , wherein the heat-treated aluminum alloy product exhibits a corrosion depth of from 25 μm to 50 μm when the quench rate is less than or about 125° C./s. 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . The method of  claim 1 , further comprising subjecting the rolled aluminum alloy product to a hot forming process after heating the rolled aluminum alloy product. 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . The method of  claim 1 , further comprising aging the heat-treated aluminum alloy product to a T6 temper or to a T7 temper. 
     
     
         23 . (canceled) 
     
     
         24 . The method of  claim 1 , further comprising heating the heat-treated aluminum alloy product to a temperature from 100° C. to 170° C. and maintaining at the temperature for 12 hours to 30 hours. 
     
     
         25 . The method of  claim 1 , wherein the heat-treated aluminum alloy product exhibits an ultimate tensile strength of from 500 MPa to 650 MPa, a yield strength of from 400 MPa to 600 MPa, a uniform elongation of from 7.50% to 10.50%, a total elongation of from 10.00% to 15.00%, a strain ratio of from 0.375 to 0.425, and/or precipitate-free zone widths of from 10 nm to 110 nm. 
     
     
         26 - 35 . (canceled) 
     
     
         36 . A product comprising:
 a heat-treated aluminum alloy product, wherein the heat-treated aluminum alloy is a rolled 7xxx series aluminum alloy product comprising:   from 4.00 wt. % to 15.00 wt. % Zn,   from 0.10 wt. % to 3.50 wt. % Cu,   from 1.00 wt. % to 4.00 wt. % Mg,   from 0.05 wt. % to 0.50 wt. % Fe,   from 0.05 wt. % to 0.30 wt. % Si,   from 0.05 wt. % to 0.25 wt. % Zr,   up to 0.25 wt. % Mn,   up to 0.20 wt. % Cr,   up to 0.15 wt. % Ti,   up to 0.15 wt. % of impurities, and   Al, and   exhibiting a strain ratio of from 0.3 to 0.8, wherein the strain ratio is determined according to an ASTM G129 standard test method.   
     
     
         37 - 53 . (canceled) 
     
     
         54 . The product of  claim 36 , generated according to the method of  claim 1 . 
     
     
         55 . An automotive product or an aerospace product incorporating the product of  claim 36 . 
     
     
         56 - 58 . (canceled)