7xxx alloy components for defense application with an improved spall resistance

Abstract

The present application relates to armor components made of high strength aluminum, such as 7xxx series aluminum alloys, which may be employed in civil or military ballistic protection systems. It relates more particularly to armor components such as armor hull walls and add-on armor appliques in vehicles.

What is claimed is: 
     
         1 . A method of producing an armor component, comprising:
 a) casting a 7XXX series aluminum alloy to obtain an ingot, wherein said alloy comprises or consists essentially of
 8.4 wt. %≤Zn≤10.5 wt. %; 
 1.3 wt. %≤Mg≤2 wt. %; 
 1.2 wt. %≤Cu≤2 wt. %; 
 at least one dispersoid forming element, with a total content of dispersoid forming elements of at least 0.04 wt. %; 
 the remainder substantially including aluminum, incidental elements, and impurities; 
   b) homogenizing said ingot;   c) hot working said homogenized ingot to obtain a plate having a first thickness T1;   d) cold working the plate having the first thickness to obtain a plate having a second thickness T2, wherein T2=T1−(x 1 *T2)/100 and 0.5≤x 1 ≤15;   e) solution heat treating;   f) quenching; and   g) aging.   
     
     
         2 . The method of  claim 1 , wherein 2≤x 1 ≤10, optionally 4≤x 1 ≤8. 
     
     
         3 . The method of  claim 1 , wherein d) is a cold rolling step. 
     
     
         4 . The method of  claim 1 , wherein g) includes at least a two step aging. 
     
     
         5 . The method of  claim 4 , wherein said two-step aging includes:
 a first aging of about 4-8 hours at about 110° C. to 130° C.; and   a second aging of about 12-20 hours at about 130° C. to 180° C.   
     
     
         6 . The method of  claim 1 , wherein g) is performed so that the total equivalent time at 150° C. is between about 5 h to about 50 h, optionally about 10 h to about 50 h. 
     
     
         7 . The method of  claim 1 , including, between f) and g), another cold working to obtain a plate having a third thickness T3. 
     
     
         8 . The method of  claim 7 , wherein said cold working to obtain a plate having a third thickness T3 results in a plastic deformation ranging from 1% to 3%. 
     
     
         9 . The method of  claim 7 , wherein said cold working to obtain a plate having a third thickness T3 comprises or consists of stretching. 
     
     
         10 . The method of  claim 1 , resulting in an armor component having a final thickness ranging between 0.5 inch and 3 inches. 
     
     
         11 . The method of  claim 1 , wherein said 7XXX series aluminum alloy comprises Zr as a dispersoid forming element, wherein 0.04 wt. %≤Zr≤0.15 wt. %. 
     
     
         12 . The method of  claim 1 , wherein 0.04 wt. %≤Zr≤0.08 wt. %. 
     
     
         13 . An armor component produced from a 7XXX series aluminum alloy comprising or consisting essentially of:
 8.4 wt. %≤Zn≤10.5 wt. %;   1.3 wt. %≤Mg≤2 wt. %;   1.2 wt. %≤Cu≤2 wt. %;   at least one dispersoid forming element, with a total content of dispersoid forming elements of at least 0.04 wt. %;   the remainder substantially including aluminum, incidental elements, and impurities; wherein said 7xxx series aluminum alloy is in the form of a plate having a final thickness of about 0.5 to about 3 inches and is manufactured by:   a) casting said 7XXX series aluminum alloy to obtain an ingot,   b) homogenizing said ingot;   c) hot working said homogenized ingot to obtain an plate having a first thickness T1;   d) cold working the plate having the first thickness to obtain a plate having a second thickness T2, wherein T2=T1−(x 1 *T2)/100 and 0.5≤x 1 ≤15;   e) solution heat treating;   f) quenching; and   g) aging;   so as to achieve an improved spall resistance compared to an armor component obtained with the same manufacturing process except that said manufacturing process does not comprise cold working before the solution heat treatment.   
     
     
         14 . The armor component of  claim 13 , wherein said 7xxx series aluminum alloy comprises Zr as a dispersoid forming element, and optionally wherein 0.04 wt. %≤Zr≤0.15 wt. %. 
     
     
         15 . The armor component of  claim 14 , wherein 0.04 wt. %≤Zr≤0.08 wt. %