What is the Difference Between Alclad and Bare Aluminum?

Aluminum has numeral uses in almost all industries around the world, its manufacture was scaled significantly during the First and Second World Wars, for use in aviation. Alclad could in many ways be compared to alloying.

What is Alclad Aluminum?

Aluminum is used extensively for its lightweight, high-strength properties in aviation. One failing however of traditional and modern high-strength aluminum alloys, it’s their relatively low corrosion resistance.

Pure aluminum however has a much higher corrosion resistance. Alclad material combines the two, coating magnesium and magnesium alloyed aluminum with a very thin layer (between 1 and 15% of the total thickness) of pure aluminum.

Is Alclad and All-Clad the same?

Despite the naming being very similar, Alclad is an industrial grade aluminum alloy system, and All-Clad is an American brand producing bonded cookware – traditionally stainless steel pans with an aluminum or copper core to aid heat distribution.

What are the Benefits of Alclad Sheet?

Alclad achieves two distinct benefits over bare aluminum; it retains the high strength of manganese magnesium-aluminum alloys but with the corrosion protection of pure aluminum.

This enables its use in high-stress applications where secondary corrosion protection is not easily achieved, such as in aircraft structural components and fuselages.

Physical and Chemical Properties of Alclad

Many aluminum grades can be provided in Alclad form, enabling the specific properties of the base alloy to be selected depending on the project.

A commonly used grade is 2024, which offers extremely high tensile strength, with good workability. Like most alclad products, weldability is low, but resistance welding methods such as spot or pinch welds can be used.

Considerations when Using Alclad Material

As Alclad aluminum sheet is not one homogenous material, it should be treated in the same fashion as plated or pre-galvanized sheet. This gives it some inherent drawbacks when manufacturing.

Weight: Thanks to the extra layer used solely for corrosion resistance, alclad sheet is heavier than using the alloy sheet without cladding. This generally comes at an overall efficiency loss, as the soft malleable pure aluminum does not add much to the overall strength of the part.

Manufacturing: Because of the layered nature of Alclad, processes that cut, melt or otherwise damage this layer will have an effect on the corrosion resistance. Traditional arc welding is not recommended, but spot or flash welding can be made effective.

Cost: whilst pure aluminum in itself is not infinitively expensive, adding that extra cost can make parts made from Alclad significantly more costly than those in high performance aluminum alloys alone.

Alclad Uses

Owing to its unique properties, Alclad has a number of industrial applications, all making use of its high strength and corrosion resistance.

Aviation: Alclad is commonly used for aircraft construction, used in components ranging from bracketry to entire fuselages. The first use of Alclad in an aviation application was the only successful metal clad airship, the Detroit ZMC-2.

Other aviation uses include airplane cowlings, fuselages and wing skins, where the large surface area but thin material suffered from corrosion when using aluminum alloys.

Aluminum Sheet for Your Project

Metals Supermarkets can offer a variety of aluminum alloys in sheet, bar and tube form, to cater to most all projects. Select a material type here, or find your local store today.