2024 was the first Al-Cu-Mg alloy to have a yield strength approaching 50,000-psi and generally replaced 2017-T4
(Duralumin) as the predominant 2XXX series aircraft alloy. With its relatively good fatigue resistance,
especially in thick plate forms, alloy 2024 continues to be specified for many aerospace structural
applications. 2024 varient alloys, such as higher purity 2124 and 2324, with improvements in
strength and other specific characteristics, have also found application in critical aircraft structures.
An improved sheet alloy for fuselage applications was introduced in 1991. Alclad C188 offers
improved fracture toughness and fatigue crack growth while maintaining the strength characteristics
of 2024Alloy 2024 plate products are used in fuselage structurals, wing tension members, shear webs and
ribs and structural areas where stiffness, fatigue performance and good strength are required. Sheet
products, usually alclad, are used extensively in commercial and military aircraft for fuselage skins,
wing skins and engine areas where elevated temperatures to 250°F (121°C) are often encountered.
Alloy 2024 is available in bare and alclad sheet and plate product forms in the annealed state and
several tempers of T3, T4, and T8 types.
- AMS-QQ-A-250/4, QQA250/4
AMS-4035, AMS4035, BAMS 516-010
AMS-4037, AMS4037, FMS-1010
MMS-1412 (All Tempers)
2024-T3 This is the most commom of the the high-strength alloys. Aircraft quaility. 2024 T3 aluminum sheet is thought of as the aircraft alloy because of it's strength. It has excellent fatigue resistance. Welding is generally not recommended. Typical uses for 2024-T3 alclad aluminum sheet are aircraft skins, cowls, aircraft structures, and also for RV repair and restortation like Airstreams because of it's shiny finish (2024T3 alclad)
CHEMICAL COMPOSITION LIMITS (WT.%)
Si . . . 0.50 Zn . . . . . . . . . 0.25
Fe. . . 0.50 Ti . . . . . . . . . . 0.15
Cu . . 3.8-4.9 Others, each . . 0.05
Mn . . 0.30-0.9 Others, total . . 0.15
Mg . . 1.2-1.8 Balance, Aluminum
Cr. . . 0.10
Note: Value maximum if range not shown.
- CORROSION RESISTANCE
All alloys of the 2XXX series are susceptible to
atmospheric corrosion, especially in industrial
or seacoast atmospheres. These alloys should
be protected, at least on faying surfaces, when
exposed to these conditions. Alcladding these
alloys provides high resistance to atmospheric
corrosion. The clad surface is resistant to
corrosive attack and also provides additional
cathodic protection to the core alloy.
THICKNESSES:: STANDARD 48" X 144" SHEETS
- 2024-T3 .016
- 2024-T3 .020
- 2024-T3 .025
- 2024-T3 .032
- 2024-T3 .040
- 2024-T3 .045
- 2024-T3 .050
- 2024-T3 .056
- 2024-T3 .063
- 2024-T3 .071
- 2024-T3 .080
- 2024-T3 .090
- 2024-T3 .100
- 2024-T3 .125
- Alloy 2024 in the T351 and T851 tempers has not experienced any in-service problems with exfoliation.
In laboratory tests for exfoliation, alloy 2024-T851 material was essentially immune in any test plane.
Stress Corrosion Cracking Resistance
In the T851 temper, alloy 2024 has very good resistance to SCC. Control of quenching and artificial
aging of 2XXX high strength alloys that have been heat treated has been effective in developing a high
resistance to stress-corrosion cracking. In over 20 years of service experience there have been no
reported incidents of SCC failures in 2024-T351 or 2024-T851 materials.
- THERMAL TREATMENT
Many heat treatments and heat treating practices are available to
develop optimum strength, toughness and other desirable characteristics
for proper application of alloy 7075-T6 sheet and plate
products. Refer to MIL-H-6088, Heat Treatment of Aluminum
Alloys for additional information.
OTHER PRODUCT FORMS
The recommended practices for heat-treating and aging alloy 2024 sheet and plate are described in
MIL-H-6088, Heat Treatment of Aluminum Alloys.
1. Alcoa Green Letter No. 188, Avoiding Stress-
Corrosion Cracking in high-Strength Aluminum Alloys.
2. MIL-H-6088, Heat Treatment of Aluminum Alloys.
3. MIL-HDBK-5D, May 1985