7xxx alloy defence applications with a balanced armor piercing fragmentation performance

1. An armor component produced from a 7xxx series aluminum alloy, wherein the aluminum alloy consists essentially of:

8.4 wt. %≤Zn≤10.5 wt. %

1.75 wt. %≤Mg≤2 wt. %,

1.2 wt. %≤Cu≤2 wt. %

at least one dispersoid forming element selected from the group consisting of Zr, Sc, V, Hf, Ti, Cr, and Mn, with a total dispersoid forming element content higher than 0.05 wt. %,

wherein if the dispersoid forming element is Zr, the dispersoid forming element content is less than 0.15%,

wherein if the dispersoid forming element is Sc, Cr, Hf, or V, the dispersoid forming element content is less than 0.3%, and

wherein if the dispersoid forming element is Mn, the dispersoid forming element content is at most 0.3%;

the remainder substantially aluminum, incidental elements and impurities;

wherein the 7XXX alloy is in the form of a plate having a thickness of 0.5 to 3 inches;

wherein the 7XXX alloy is aged to achieve:

(i) a fragment simulated particles V50 ballistic limit such that

V 50(FSP20 mm)>1633 T 2 −1479 T+ 1290

where T is the thickness plate (unit: inch) and the unit of V50 is feet/s;

(ii) an armor piercing V50 ballistic limit such that:

V 50(0.30cal AP M 2)>−282 T 2 +1850 T+ 610

where T is the thickness plate (unit: inch) and the unit of V50 is feet/s.

2. An armor component according to claim 1 , wherein Mg/Zn≤0.20.

3. An armor component according to claim 1 , wherein 0.9≤Cu/Mg≤1.1.

4. An armor component according to claim 1 , wherein the dispersoid forming element is essentially zirconium, whose content is higher than 0.05 wt. % and less than 0.15 wt. %.

5. An armor component according to claim 1 , wherein Fe<0.1 wt. % and Si<0.1 wt. %.

6. An armor component according to claim 1 , wherein said 7xxx alloy in the form of a plate is manufactured by:

a) casting said alloy into ingot form;

b) homogenising said ingot;

c) hot working said ingot to obtain a plate;

d) solution heat treating;

e) quenching;

f) optionally stretching to obtain a plastic deformation from about 1 and about 3%;

g) aging corresponding to the following treatment: 4-8 hours at 110° C.-130° C.+12-20 hours at 140° C.-160° C.

7. An armor component according to claim 1 , wherein said 7xxx alloy in the form of a plate is manufactured by:

a) casting said alloy into ingot form;

b) homogenising said ingot;

c) hot working said ingot to obtain a plate;

d) solution heat treating;

e) quenching;

f) optionally stretching to obtain a plastic deformation between 1 and 3%;

g) aging, a total equivalent time at 150° C. of aging treatment not exceeding 25 h.

8. An armor component according to claim 1 , wherein the 7xxx series aluminum alloy consists essentially of:

8.5 wt. %≤Zn≤9.5 wt. %;

1.75 wt. %≤Mg≤2 wt. %,

1.4 wt. %≤Cu≤1.8 wt. %;

Fe<0.1 wt. %;

Si<0.1 wt. %;

0.05 wt. %≤Zr≤0.15 wt. %; balance aluminum and incidental elements and impurities.

9. An armor component according to claim 8 , wherein 1.8 wt. %≤Mg≤2 wt. %.

10. An armor component according to claim 1 , wherein FSP V50 ballistics limit is such that:

V 50(FSP20 mm)>1633 T 2 −1479 T+ 1320   (I-a)

where T is the thickness plate (unit: inch) and the unit of V50 is feet/s.

11. An armor component according to claim 1 , wherein FSP V50 ballistics limit is such that:

V 50(FSP20 mm)>1633 T 2 −1479 T+ 1350   (I-b)

where T is the thickness plate (unit: inch) and the unit of V50 is feet/s.

12. An armor component according to claim 1 , wherein AP V50 ballistics limit is such that:

V 50(0.30cal AP M 2)>−282 T 2 +1850 T+ 700   (II-a)

where T is the thickness plate (unit: inch) and the unit of V50 is feet/s.

13. An armor component according to claim 1 , wherein AP V50 ballistics limit is such that:

V 50(0.30cal AP M 2)>−282 T 2 +1850 T+ 790   (II-b)

where T is the thickness plate (unit: inch) and the unit of V50 is feet/s.

14. An armor component according to claim 1 , wherein said plate is fusion welded and wherein the post-weld ultimate tensile strength is greater than 45%, of the ultimate tensile strength before welding.

15. An armor component according to claim 1 , wherein said plate is fusion welded and wherein the post-weld tensile strength is greater than 47 ksi.

16. A method of producing an armour component according to claim 1 , comprising:

a) casting said alloy into ingot form;

b) homogenising said ingot;

c) hot working said ingot to obtain a plate;

d) solution heat treating;

e) quenching;

f) optionally stretching to obtain a plastic deformation from 1 and 3%;

g) aging corresponding to the following treatment: 4-8 hours at 110° C.-130° C.+12-20 hours at 140° C.-160° C.

17. A method of producing an armour component according to claim 1 , comprising:

a) casting said alloy into ingot form;

b) homogenising said ingot;

c) hot working said ingot to obtain a plate;

d) solution heat treating;

e) quenching;

f) optionally stretching to obtain a plastic deformation between 1 and 3%;

g) aging, a total equivalent time at 150° C. of aging treatment not exceeding 25 h.

18. An armor component according to claim 1 , wherein said plate is fusion welded and wherein the post-weld ultimate tensile strength is greater than 50% of the ultimate tensile strength before welding.

19. An armor component according to claim 1 , wherein said plate is fusion welded and wherein the post-weld tensile strength is greater than 47 ksi.

20. An armor component according to claim 1 , wherein the 7xxx series aluminum alloy consists essentially of:

8.5 wt. %≤Zn≤9.0 wt. %;

1.8 wt. %≤Mg≤2 wt. %,

1.4 wt. %≤Cu≤1.8 wt. %;

Fe<0.1 wt. %;

Si<0.1 wt. %;

0.05 wt. %<Zr<0.15 wt. %; balance aluminum and incidental elements and impurities;

wherein the 7XXX alloy is in the form of a plate having a thickness of about 0.5 to about 3 inches;

wherein the 7XXX alloy is aged to achieve:

(i) a fragment simulated particles V50 ballistic limit such that

V 50(FSP20 mm)>1633 T 2 −1479 T+ 1350

where T is the thickness plate (unit: inch) and the unit of V50 is feet/s;

(ii) an armor piercing V50 ballistic limit such that:

V 50(0.30cal AP M 2)>−282 T 2 +1850 T+ 790

where T is the thickness plate (unit: inch) and the unit of V50 is feet/s.