Aluminum 5052 - EN AW-5052 - EN AW-AlMg2,5 - 3.3524 - AL-P5052

How did 5052 aluminum alloy originate?

5052 first appeared under the designation 52S in the 1930s, following a publication by Alcoa. This alloy offers moderate—indeed quite good—strength considering it is non–heat treatable (Al-Mg-Cr). Its development aimed at competitive manufacturing and in-service costs, in the broader context of industrialization and rapid aluminum adoption. Its standardization in 1954 by the Aluminum Association is what assigned it the AA5052 designation.

After World War II, the expansion of aluminum use established 5052 as a go-to “mid-strength” sheet alloy for a wide range of fabricated parts. A hallmark application is road signage made from 5052 sheet, typically in the H38 temper to maximize stiffness and retention of shape.

What is the chemical composition of 5052, and what does each element do?

5052 is an Al-Mg alloy with ~ 2.2–2.8% magnesium and an addition of ~ 0.15–0.35%chromium. Its near absence of Cu explains its excellent corrosion resistance, particularly in saline environments.

Magnesium markedly increases aluminum’s mechanical strength and improves its response to cold working, while the small chromium addition helps refine grain structure and tie up certain impurities (such as iron), improving resistance to intergranular corrosion.

While it allows controlled impurity levels (see the table below), a 5652 variant exists with tighter impurity limits, without fundamentally changing the core service properties of 5052.

Which metallurgical tempers are used, and with what effects?

As a non–heat-treatable alloy, 5052 is “tuned” through strain hardening (the Hxx tempers) and annealing. The O temper maximizes ductility; typical steps are H32 (~25%), H34 (~50%), H36 (~75%), H38 (~100%).

Strain hardening raises Rp0.2 from about 90 MPa (O) to ~ 255 MPa (H38), and Rm from ~ 195 MPa (O) to ~ 290 MPa (H38), while elongation drops from ~ 25% to ~ 12% in the higher-H tempers. A mild thermal stabilization step can relieve residual stresses without introducing any structural age-hardening.

The alloy is most commonly supplied as sheet/coil (H32/H34), bars, extruded shapes, drawn tube (O, H14/H32), and wire—reflecting a wide property window depending on processing.

What mechanical properties does 5052 exhibit as a function of temperature?

In fatigue, performance is reasonable for an aluminum alloy, with an indicative limit for 5052-H32 of about 110 MPa (50% probability of failure at 10⁷ cycles, R = −1). Its microstructure, without coarse particles, together with Mg content, supports good toughness compared with very high-strength but more brittle alloys (such as 7075).

Low temperature increases strength while maintaining ductility; at elevated temperature (> ~ 200 °C), strength decreases due to recovery/recrystallization and softening. Mg-rich 5000-series alloys can sensitize in the 60–100 °C range under prolonged exposure; with only ~ 2.5% Mg, 5052 is less critical, but continuous service below ~ 65 °C is commonly recommended to avoid microstructural degradation.

Typical mechanical properties (sheet)

Which physical and chemical properties characterize 5052?

Constants are in line with aluminum alloys: E ~ 70 GPa, ν ~ 0.33, ρ ~ 2.68 g/cm³. Melting range: 607–649 °C, k ~ 138 W/m·K (25 °C), α ~ 23.8×10⁻⁶ K⁻¹ (20–100 °C), electrical resistivity ~ 50 nΩ·m. Chemically, the alloy forms a stable protective alumina layer; the lack of Cu limits internal galvanic effects, which explains its excellent resistance in natural atmospheres and salt water.

Corrosion resistance by environment

In marine exposure, 5052 develops a protective patina and performs clearly better than Al-Cu alloys (2000/7000 series). For heavy marine structures, however, 5083/5456 are preferred for higher strength, with broadly comparable corrosion resistance.

In industrial atmospheres (moderate pollutants), the oxide film provides effective protection. Avoid strong acids/bases that dissolve alumina. In highly aggressive environments, anodizing or painting is therefore advisable. Its durability in air, fresh water/seawater, hydrocarbons, and neutral solvents supports its use in tanks and piping.

How does it perform in forming, machining, and welding?

In forming, the alloy is highly workable in O or low-H tempers: tight-radius bending, deep drawing of vessels/tanks, and axisymmetric shapes (spinning) are common. Intermediate anneals (~ 345 °C) can restore ductility during high-strain forming sequences.
In machining, the rating is fair: better in strain-hardened condition than in O, with generous lubrication and sharp tools (positive rake) to limit built-up edge and heat.
In welding, the rating is excellent in TIG/MIG with a compatible Al-Mg filler: joints are strong and ductile, with no loss of properties associated with heat treatment (since there is none). Spot welding works well in thin gauges. Brazing can be acceptable, but tin-based soldering is not recommended.

Typical applications (aerospace, marine, industry)

Aerospace: fuel tanks in 5052-H32 (sheet 1–2 mm), oil/fuel lines in drawn tube (easy bending), non-structural sheet-metal parts (fairings, enclosures, liners).
Marine: small craft hulls, superstructures, equipment (tanks, seawater heat exchangers, compartments), excellent performance in salt spray; heavy structures more often in 5083/5456.
Architecture/roadway: façades, sunshades, railings, road signs in 5052-H38.
Consumer/industrial: refrigerator panels, vessels/cisterns, welded frames, machine panels, wire/fencing.

How does it compare with neighboring alloys?

6061-T6: stronger (~ 310 MPa) but less formable; weldable with loss of T6 temper in the HAZ; post-weld thermal steps may be used. 5052 retains more uniform properties around the joint, which is why it’s attractive for formed/welded parts in corrosive environments.
5083: stronger (higher Mg), better for heavy marine/cryogenic structures, but less formable and more sensitive to sensitization in thicker sections.
5754: very close, often slightly stronger in sheet; excellent formability, easy welding; machining is sometimes perceived as marginally better.
3003: much softer (~ 190 MPa in H24), extremely formable but intended for low-stress service; in marine exposure, 5052 is preferred.