Metal sheet made of high-strength 2XXX alloy for an aircraft fuselage

1. A thin sheet which is made of an alloy based on mainly recrystallized aluminum and which has a thickness between 0.25 and 12 mm comprising, as a % by weight,

Cu 3.4-4.0;

Mg 0.5-0.8;

Mn 0.1-0.7;

Fe≤0.15;

Si≤ 0.15;

Zr≤ 0.04;

Ag 0.01-0.25;

Zn<0.1;

other elements ≤0.05 each and ≤0.15 in total;

wherein the Cu/Mg ratio is between 5 to 5.5;

remainder aluminum.

2. The thin sheet according to claim 1 , wherein the Cu content is between 3.4 and 3.8% by weight.

3. The thin sheet according to claim 1 , wherein the Mg content is between 0.55 and 0.75% by weight.

4. The thin sheet according to claim 1 , wherein the Mn content is between 0.2 and 0.5% by weight.

5. The thin sheet according to claim 1 , wherein the Zr content is between 0.01 and 0.04% by weight or less than 0.01% by weight.

6. The thin sheet according to claim 1 , wherein:

the Ag content is less than 0.1% by weight and the Zn content is less than 0.1% by weight.

7. The thin sheet according to claim 1 , wherein, in the T8 temper, said sheet comprises at least two of the following properties, optionally at least three, optionally all of the following properties:

UPE (T−L)>−0.00175 R p0.2 (LT)+0.93

where UPE (T−L) is in J/mm 2 and R p0.2 (LT) in MPa;

UPE (T−L) >0.3 J/mm 2 ;

crack growth rate da/dN less than or equal to 3.6 10 −4 mm/cycle for a ΔK of 15 MPa√m;

density less than 2.800

R p0.2 (LT) >355 MPa.

8. The thin sheet according to claim 1 , wherein recrystallized grains have on an LxST section at mid-thickness an aspect ratio, optionally wherein, a ratio between the mean length and the mean thickness less than or equal to 6.

9. A product comprising a thin sheet according to claim 1 for use as a fuselage sheet.

10. The thin sheet according to claim 1 , wherein the thickness is between 0.3 and 8 mm.

11. The thin sheet according to claim 1 , wherein the thin sheet is manufactured using a process successively comprising:

a. producing a liquid metal bath comprising, as a percentage by weight, Cu 3.4-4.0; Mg 0.5-0.8; Mn 0.1-0.7; Fe≤0.15; Si≤0.15; Zr≤0.04; Ag 0.01-0.25; Zn<0.1; other elements ≤0.05 each and ≤0.15 in total; the Cu/Mg ratio is between 5 to 5.5; remainder aluminum;

b. casting a rolling ingot said liquid metal bath;

c. homogenizing said rolling ingot;

d. hot rolling and, optionally cold rolling said rolling ingot into a sheet having a final thickness between 0.5 and 12 mm;

e. solution heat treatment and quenching of said sheet;

f. controlled stretching of said sheet with a permanent set of 0.5 to 6%;

g. aging the stretched sheet by heating at a temperature between 130 and 180° C. for a time of 10 to 100h.

12. The thin sheet according to claim 11 , wherein the rolling ingot is homogenized at a temperature between 480 and 560° C., for a time of 4 to 20h.

13. The thin sheet according to claim 11 , wherein before d., the rolling ingot is heated at a temperature of 420 to 480° C. for 10 to 20h.

14. The thin sheet according to claim 11 , wherein the solution heat treatment is performed at a temperature between 490 and 560° C. for 20 minutes to 2h.

15. A process for manufacturing a thin sheet which is made of an alloy based on mainly recrystallized aluminum which has a thickness of between 0.25 and 12 mm comprising successively:

a. producing a liquid metal bath comprising, as a percentage by weight, Cu 3.4-4.0; Mg 0.5-0.8; Mn 0.1-0.7; Fe≤0.15; Si≤0.15; Zr≤0.04; Ag 0.01-0.25; Zn<0.1; other elements ≤0.05 each and ≤0.15 in total; the Cu/Mg ratio is between 5 to 5.5; remainder aluminum;

b. casting a rolling ingot said liquid metal bath;

c. homogenizing said rolling ingot;

d. hot rolling and, optionally cold rolling said rolling ingot into a sheet having a final thickness between 0.5 and 12 mm;

e. solution heat treatment and quenching of said sheet;

f. controlled stretching of said sheet with a permanent set of 0.5 to 6%;

g. aging the stretched sheet by heating at a temperature between 130 and 180° C. for a time of 10 to 100h.

16. The process for manufacturing a thin sheet made of aluminum based alloy according to claim 15 , wherein aging of stretched sheet is carried out by heating at a temperature between 155 and 165° C. for a time of 28 to 60h.

17. The process for manufacturing a thin sheet made of aluminum based alloy according to claim 15 , wherein aging of stretched sheet is carried out by heating at a temperature between 170 and 190° C. for a time of 10 to 20h.