CLAD 2XXX-SERIES AEROSPACE PRODUCT

1 . A rolled composite aerospace product ( 10 ) comprising a 2XXX-series core layer ( 20 ) and an Al—Mn alloy layer ( 30 ) coupled to at least one surface of the 2XXX-series core layer and wherein the Al—Mn alloy layer ( 30 ) is of a 3XXX-series aluminium alloy comprising 0.3% to 2.0% Mn.

2 . The rolled composite aerospace product according to claim 1 , wherein the Al—Mn alloy layer ( 30 ) is of a 3XXX-series aluminium alloy having a composition of, in wt. %:

Mn

0.5 to 2.0,

Si

up to 1.2,

Fe

up to 0.7,

Cu

up to 1.5,

Mg

up to 1.0,

Cr

up to 0.25,

Zr

up to 0.25,

Ti

up to 0.25,

Zn

up to 1.5,

other elements and impurities each <0.05,

total <0.15; balance aluminium.

3 . The rolled composite aerospace product according to claim 2 , wherein the Mg-content is in a range of 0.1% to 0.7% and the Cu-content is in a range of 0.20% to 1.2%.

4 . The rolled composite aerospace product according to claim 2 , wherein the Mg-content is in a range of 0.1% to 0.7% and the Cu-content is up to 0.25%.

5 . The rolled composite aerospace product according to claim 2 , wherein the Mg-content is up to 0.25% and Cu-content is in a range of 0.20% to 1.2%.

6 . The rolled composite aerospace product according to claim 2 , wherein the Mg-content is up to 0.20% and the Cu-content is up to 0.25%.

7 . The rolled composite aerospace product according to claim 1 , wherein the Al—Mn alloy layer ( 30 ) is non-homogenized.

8 . The rolled composite aerospace product according to claim 1 , wherein the Al—Mn alloy layer ( 30 ) is homogenized.

9 . The rolled composite aerospace product according to claim 1 , wherein the Al—Mn alloy layer (30) is coupled by means of roll bonding to the at least one surface of the 2XXX-series core layer ( 20 ).

10 . The rolled composite aerospace product according to claim 1 , wherein each Al—Mn alloy layer (30) has a thickness in the range of 1% to 20% of the total thickness of the rolled composite aerospace product ( 10 ).

11 . The rolled composite aerospace product according to claim 1 , consisting of a 2XXX-series core layer ( 20 ) and an Al—Mn alloy layer ( 30 ) coupled to one surface of the 2XXX-series core layer ( 20 ).

12 . The rolled composite aerospace product according to claim 1 , consisting of a 2XXX-series core layer ( 20 ) and an Al—Mn alloy layer ( 30 ) coupled to both surfaces of the 2XXX-series core layer ( 20 ).

13 . The rolled composite aerospace product according to claim 1 , wherein the 2XXX-series alloy of the core layer ( 20 ) has a composition of, in wt. %,

Cu

1.9% to 7.0%;

Mg

0.30 % to 1.8%,

Mn

up to 1.2%;

Si

up to 0.40%;

Fe

up to 0.40%;

Cr

up to 0.35%;

Zn

up to 1.0%;

Ti

up to 0.15%;

Zr

up to 0.25;

V

up to 0.25%;

Li

up to 2.0%;

Ag

up to 0.80%;

Ni

up to 2.5%; and

balance being aluminium and impurities.

14 . The rolled composite aerospace product according to claim 1 , wherein the 2XXX-series core layer ( 20 ) is from the 2×24-series alloy.

15 . The rolled composite aerospace product according to claim 1 , wherein the 2XXX-series core layer ( 20 ) is in a T3, T351, T39, T42, T8 or T851 temper.

16 . The rolled composite aerospace product according to claim 1 , wherein an interliner ( 40 ) is positioned between the 2XXX-series core layer ( 20 ) and the Al—Mn alloy layer ( 30 ), and wherein the interliner ( 40 ) is made from a different 3XXX-series aluminium alloy than the Al—Mn alloy layer ( 30 ), the interliner ( 40 ) being made from a 3XXX-series aluminium alloy comprising 0.3% to 2.0% Mn and 0.25% to 4% Zn.

17 . The rolled composite aerospace product according to claim 1 , wherein an interliner ( 40 ) is positioned between the 2XXX-series core layer ( 20 ) and the Al—Mn alloy layer ( 30 ), and wherein the interliner ( 40 ) is made from a different 3XXX-series aluminium alloy than the Al—Mn alloy layer ( 30 ), the interliner ( 40 ) being made from a 3XXX-series aluminium alloy comprising, in wt. %,

Mn

0.3% to 2.0%;

Zn

0.25% to 4%;

Si

to 1.2%;

Fe

to 0.7%;

Cu

to 1.5%;

Mg

to 1.0%;

Cr

up to 0.25%;

Zr

up to 0.25%;

Ti

up to 0.25%; and

other elements and impurities each <0.05%,

total <0.15%, and balance aluminium.

18 . The rolled composite aerospace product according to claim 1 , wherein the rolled composite aerospace product ( 10 ) has a total thickness of 0.8 mm to 50.8 mm.

19 . The rolled composite aerospace product according to claim 1 , wherein the rolled composite aerospace product is an aerospace structural part.

20 . A method of manufacturing a rolled composite aerospace product according to claim 1 , comprising the steps of:

providing an ingot of a 2xxx-series aluminium alloy for forming the core layer of the composite aerospace product;

homogenizing the ingot of the 2xxx-series aluminium alloy at a temperature in the range of 400° C. to 505° C. for at least 2 hours;

providing an ingot or rolled clad liner of a 3xxx-series aluminium alloy for forming an outer clad layer on the 2xxx-series core aluminium alloy;

optionally homogenizing the ingot of the 3xxx-series aluminium alloy at a temperature in the range of at least 450° C. for at least 1 hour;

roll bonding the 3xxx-series aluminium alloy to the 2xxx-series core alloy to form a roll bonded product, optionally followed by cold rolling;

solution heat-treating the roll bonded product at a temperature in the range of 450° C. to 505° C.;

cooling of the solution heat-treated roll bonded product to below 100° C.;

optionally stretching of the solution heat-treated and cooled roll bonded product; and

ageing of the cooled roll bonded product.

21 . The method according to claim 20 , wherein the method further comprises forming of the solution heat-treated and cooled roll bonded product, and optionally also being stretched, in a forming process into a predetermined shape product with a uniaxial or a biaxial curvature.

22 . The method according to claim 20 , wherein a forming step is performed after the ageing step.

23 . The method according to claim 21 , wherein the forming step and the ageing step are combined in a forming step at elevated temperature.