Aluminium 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 Aluminium?

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

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

What are the Benefits of Alclad Sheet?

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

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 aluminium 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 are 2014 and 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 aluminium 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 aluminium 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 aluminium in itself is not infinitively expensive, adding that extra cost can make parts made from Alclad significantly more costly than those in high performance aluminium 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 aluminium alloys.

Aluminium Sheet for Your Project

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