Aluminum 5005 - EN AW-5005 - EN AW-AlMg1(B)

What is 5005 and which international standards apply to it?

Metallurgical family and scope of use

Aluminium alloy 5005 belongs to the 5000 series (Al-Mg) and is supplied exclusively as a wrought product (no casting). It is work-hardenable (strengthening by cold deformation) and non-heat-treatable (no structural hardening by heat treatment), which favours sheet metal forming processes and weldability. Its introduction in the mid-20th century answered the need for materials that are easy to weld and corrosion-resistant, especially in marine environments.

Designations, standards and aliases

From a standards perspective, the AA designation is 5005, the European equivalent is written EN AW-5005 (AlMg1), and the German designation corresponds to DIN number 3.3315. In addition, historical aliases persist: BS N41 or Alcan GB-B57S, as well as trade names (such as Peraluman-100). Finally, the 5657 variant (high purity) was developed to provide superior anodizing quality (AQ) with a chemistry close to that of 5005.

Composition ranges and purity

Alloy 5005 contains approximately 0.50–1.10 % Mg, the balance being aluminium with controlled impurities (Si, Fe, Cu, Mn, Cr, Zn, Ti, other elements, see table below). The total amount of alloying elements therefore remains low (≈ 1 %), which results in a high aluminium purity (~ 98 %) with precise limits depending on the standards and mill certificates.

Which tempers are available for 5005?

Being a non-heat-treatable alloy, 5005 is used in various strain-hardened tempers (designated by the prefix H). In the O temper (annealed), the alloy is fully softened and provides maximum ductility for forming. Tempers H12/H14 (¼–½ hard) are common for sheet products and target a compromise between strength and formability, while H16/H18 (¾ hard, hard) maximise strength at the expense of ductility.

Stabilised and specific tempers

The H3x series is particularly suitable for Al-Mg alloys such as 5005. Tempers H32 and H34 (strain-hardened and stabilised) limit stress relaxation and secure dimensional stability over time. Temper H111 (slightly strain-hardened), very close to the annealed condition, is used when high formability must be retained, whereas temper H112 (hot-rolled) is used where excellent weldability is required while still ensuring a certain level of mechanical properties.

What are the mechanical properties of 5005 by temper?

In the O temper, its typical yield strength is around 35 MPa and its tensile strength ~ 105–145 MPa (sheet 0.2 to 3 mm, typical values), with an elongation of ~ 12–15 % (depending on thickness, typically 1.5–6 mm). In H14, tensile strength reaches ~ 145–185 MPa and elongation drops to ~ 2–5 % (typical values). In H16/H18, tensile strength can exceed 185 MPa and Rp_0.2 reaches ~ 135 MPa.

Mechanical positioning

Overall, strain-hardened 5005 remains a medium-strength alloy, sufficient for sheet metal applications and far below heat-treatable alloys (2024, 6000, 7000 series) which often exceed 300 MPa (typical values). On the other hand, the O temper provides high ductility, useful for bending and deep drawing without cracking. Consequently, the choice of temper allows the formability/strength trade-off to be adjusted without resorting to complex heat treatments.

What are the physical and chemical properties of alloy 5005?

Physical properties of 5005 (density, modulus, expansion)

Its typical physical properties are similar to those of other wrought aluminium alloys: a density of ~ 2.70 g/cm³, a Young’s modulus of ~ 69 GPa and a Poisson’s ratio of ~ 0.33 (typical values). The coefficient of thermal expansion is ~ 23.7 × 10⁻⁶ K⁻¹ (20–100 °C) and the melting range lies between ~ 632 °C (solidus) and ~ 655 °C (liquidus). In the annealed condition, it exhibits excellent thermal conductivity (~ 200 W/m·K) and good electrical conductivity (~ 52 % IACS, decreasing in harder tempers).

Chemistry and corrosion resistance (depending on environment)

From a chemical standpoint, alloy 5005 owes its behaviour mainly to the thin alumina oxide film that forms naturally on the surface and protects it. It provides excellent resistance to general atmospheric corrosion, comparable to that of alloy 3003 (Al-Mn) in most environments. Owing to the magnesium addition, it also shows improved performance in slightly alkaline environments compared with non-heat-treatable alloys of other series.

In marine environments, 5005 performs well in seawater and salt spray, although it does not reach the corrosion resistance of higher-magnesium 5000 series alloys such as 5083. Note that with ~ 0.8 % Mg, 5005 is not particularly prone to intergranular corrosion caused by precipitation of β phases (Al₃Mg₂) – an issue that can affect 5000 series alloys containing > 3 % Mg exposed for long periods at moderate temperatures.

In the case of galvanic corrosion, like any aluminium alloy, it can corrode rapidly if coupled electrochemically to a more noble metal in a conductive environment. It is therefore advisable to avoid direct contact with steels or copper alloys in humid atmospheres, or to insert insulating barriers. Finally, in strongly acidic or reducing media (where the oxide film cannot reform), aluminium is not suitable because it will suffer significant attack.

Anodizing quality (AQ) and appearance

When anodized, 5005 produces a clear, homogeneous film, more transparent than 3003, with good colour matching to 6063. By contrast, some alloys with higher copper or silicon content (generic 2000 and 6000 series) may yield yellowish, brownish or non-uniform shades. 5005-AQ is therefore preferred for anodized façades and decorative panels where a high degree of colour uniformity is required.

How should 5005 be used (forming, machinability and welding)?

Cold forming and bend radii

Alloy 5005 is known for its good cold formability, particularly in the annealed or half-hard temper. Its plastic behaviour is excellent thanks to its moderate level of alloying elements: the high elongation in the O temper allows bending, deep drawing, rolling and spinning operations without cracking. For example, thin H32 sheets can be bent to very tight radii (≈ 0–½ × thickness) without failure, and even in the H34 temper a bend with a radius of 1 to 2 times the thickness is generally achievable.

Annealing and stabilisation

In general, forming forces and tool wear on 5005 are lower than on steel for components of comparable geometry, which facilitates its machining and sheet forming.

Alloy 5005 is not designed for hot working (forging), which is rarely applied to 5xxx series alloys. It is usually formed at room temperature or supplied in a pre-strain-hardened condition. If it needs to be softened, a standard annealing treatment can be applied (typically ~ 345 °C followed by slow cooling, without specific precautions).

Machining behaviour and parameters

Alloy 5005 can be machined satisfactorily by milling, turning and drilling, provided high cutting speeds, generous lubrication and sharp cutting edges are used. However, its relative softness calls for clean, continuous cuts to limit burrs and distortion. In comparison, its perceived machinability is lower than that of harder alloys (e.g. 2017, 6082) but better than very soft series such as 1100 or 3003.

Welding processes and filler metals

The 5000 series is renowned for its very good weldability, and 5005 is no exception. This alloy can be welded using all standard techniques: gas-shielded arc welding (GTAW/TIG, GMAW/MIG), resistance spot welding, friction stir welding (FSW), etc. TIG/MIG welds on 5005 are relatively insensitive to hot cracking, provided that the material is clean and dry (to avoid hydrogen and inclusions). Typical filler wires are alloys 4043 (Al-Si) or 5356 (Al-Mg), depending on the application. Alloy 4043 (Al-5 % Si) is often preferred for its high tolerance to hot cracking and good fluidity, whereas alloy 5356 (Al-5 % Mg) can provide a mechanically stronger weld.

Sensitisation and alternative joining methods

The low magnesium content of 5005 limits the risk of post-weld sensitisation observed in more Mg-rich alloys (e.g. 5083). On the other hand, brazing (with brass or tin, for example) remains difficult because of the tenacious oxide film, hence the interest in appropriate fluxes and specialised processes. Welding, structural adhesive bonding and mechanical fastening therefore remain the preferred joining methods.

Which alloys should be compared to 5005 depending on the application?

Versus 3000 series alloys (3003/3103 – direct competitors)

Alloys 3003 and 3103 are highly formable and cost-effective, but 5005 offers a more uniform decorative anodized finish. However, for very deep drawing operations, 3003-O may be more suitable owing to its higher initial ductility. The trade-off therefore lies between anodized appearance and extreme formability.

Versus 5052 (a “5005 2.0” with higher strength)

Alloy 5052 (~ 2.5 % Mg) typically provides ~ 25–50 % higher strength and excels in marine environments (tanks, reservoirs, light structures). However, its anodized appearance can be somewhat milky if the process is not optimised, whereas 5005-AQ offers a more uniform finish. In short, 5052 is the preferred choice when strength is the priority, and 5005 when aesthetics and formability dominate.

Versus 5083/5086 (higher-strength members of the 5000 series)

Alloys 5083 and 5086 are designed for highly stressed welded structures (marine, offshore) and are significantly stronger than 5005. However, their decorative anodizing is more difficult to control owing to their high Mg content. When much higher strength is required, it is therefore appropriate to move away from 5005 towards these grades.

Versus 6xxx/7xxx series (equivalents from other families, heat-treated)

Alloys from other families, such as 6061-T6 or 6082-T6, can achieve mechanical strengths roughly 50 to 80 % higher than those of 5005-H34, but they require heat treatment and their heat-affected zones in welds are less tolerant. Moreover, anodizing 6000 series alloys can lead to non-uniform colours (due to the influence of Si). 5005 thus remains relevant where simple processing and high-quality finishing are key.

What are the main applications of 5005 in aerospace and industry?

Aerospace uses (excluding primary structures)

In aerospace, 5005 is mainly used for non-structural components: fairings, cowlings, lightly loaded panels and anodized interior cladding. Overall, it complements structural alloys (2024, 7050, 7075) through its ease of fabrication and good surface finish.

Architecture, signage and equipment

In architecture, 5005-AQ is a standard alloy for anodized façades (curtain walls, cladding), often used together with 6063 extrusions to ensure colour matching. In addition, signage (road/urban signs) and engraved/anodized plates benefit from its easy cutting and bending and its good outdoor performance. In industrial and food-processing equipment, tanks, trays and light frames are often made from 5005 for its compatibility and surface hygiene.

Transport, marine applications and strip

In automotive and transport applications (motorhomes, trailers), sidewalls and roofs in 5005 benefit from its low density and weather resistance. In marine outfitting for non-structural parts (handrails, cladding, boxes, enclosures), 5005 in anodized or painted condition is widely used, whereas for highly stressed hull structures the choice shifts towards 5083 or 5086.