Aluminium

Aluminium is a metallic element that can be found in nature in combination with oxygen, for example aluminium oxide. The workable mineral for the manufacture of aluminium is called bauxite. Aluminium is the third most abundant element in the earth’s crust after oxygen and silicon.

Aluminium alloy

To obtain materials for a wide range of application and thereby, product improvement, other metallic elements are added to the aluminium. The alloying technique enables the properties of the original metal to be changed, for example, in terms of tensile strength, hardness, formability, surface properties, corrosion resistance, welding properties and conductivity. For aluminium profiles the most common alloy elements are magnesium and silicon. Others are manganese, copper, zinc, bismuth, chrome and titanium.

Anodising

Anodising is a surface treatment which is used to give the aluminium product additional protection against corrosion, decorative surfaces with resistant colour and gloss, electrical insulating surfaces or foundations for gluing or painting. Anodising is an electro-chemical process that strengthens the natural oxide shift.

Bauxite

In nature, aluminium is always bound to other elements, above all in the commonly spread silicates and in sparingly soluble hydrated oxides. It is the oxide, first bauxite, that is the source of aluminium production. Bauxite is predominantly found in sub-tropical regions of the world. Bauxite takes its name from \"Les Baux\" in France where it was first discovered.

Bending

The bending of aluminium can be performed both as the edge bending of sheets and as the bending of profiles over a bending jig. Generally, aluminium requires greater care when bending compared to steel, for example. Essentially, the bending radius must therefore be larger. Fracture elongation Fracture elongation specifies the percentage elongation for a specific measuring range of a test piece after loading to fracture by tensile testing.

Corrosion

Aluminium has very high resistance against corrosion. When aluminium is produced it is spontaneously covered by a thin but effective coating of oxide which protects the aluminium from further oxidation. If the coating of oxide is damaged mechanically this coating will be renewed immediately.

Dyeing

There are many ways to dye an anodising layer. One of the most common methods is to anodise in sulphuric acid and thereafter by electrolysis, introduce a dye pigment in the lower part of the pore layer. Thereafter the anodising layer is sealed. There are a number of colours to choose from, from champagne to black.

Extrusion

A production method where a aluminium billet is heated to 450-500 degrees. The source material for extrusion are round alloyed billets that after heating are pressed at high pressure through a profile die. When the profile comes out it is immediately cooled down with air or water.

Free machining aluminium alloy

When automatically processing components, stringent demands are made for fast cutting, fast feeding and good surfaces. An alloy should then be chosen that contains lead or bismuth, since those elements improve the machining qualities. The alloys known as free machining alloys are EN AW 2007, 2011, 2030, 6012, 6262 and are the most suitable for the automatic processing of components in larger production runs. Free machining alloys provide components of the right quality and at the same time, increase the reliability of production.

Galvanic corrosion

Galvanic corrosion can occur when different metals are in metallic contact with each other, at the same time that there is a continuous electrolyte bridge between the metals. Ordinarily the more ignoble metal corrodes and the most noble is protected against corrosion. Aluminium is often the most ignoble metal and consequently the risk for corrosion is greater than for most other construction material.

Gas Metal Arc Welding (MIG)

MIG welding is undertaken with direct current electricity, with argon or argon/helium mixes as the shielding gas. The welding speed of MIG is faster than for the TIG method. The speed of welding means that the size of the heat agitated area in the parent metal is smaller compared to other welding methods.

Gas Tungsten Arc Welding (TIG)

TIG welding is normally performed with alternating current electricity, with argon as the shielding gas. The electrode is of a non-melting type. Pure wolfram or wolfram alloys are usually used as electrode material. The TIG method is used for manual and mechanical welding and is suitable for thicknesses above 0.5 mm.

Hardness

The hardness specifies the material ability to resist a hard object that is pressed into the material. An example of a method of measurement for hardness is Brinell.

Heat treatable alloy

An alloy type that obtains its strength through precipitation-hardening (heat treating) and that is used for profiles. Non heat treatable alloys obtain their strength through increased additives or by cold rolling and are primarily used for sheet, foil and band.

Ingot

The starting material for extrusion or casting of aluminium is an ingot

Laser cutting

The laser cutting of aluminium using oxygen as the cutting gas is often used for thicknesses from 0.5 mm. The cut width is extremely narrow and fast cutting speeds with good profile surfaces can be achieved using this method.

Natural anodising

Anodising with no dyeing. The aluminium oxide is transparent to allow the natural surface of the aluminium to show through the anodised protective layer.

Non-alloyed aluminium

Aluminium is almost always alloyed with different metals to achieve specific properties. The most common alloy elements are silicon (Si), magnesium, Mg), manganese (Mn), copper (Cu), and zinc (Zn). Alloys that contains a maximum of 1.0 per cent by weight, of iron and silicon together, are called non-alloyed aluminium or pure aluminium.

Pad printing

Pad printing is a method used to print on rounded materials and surfaces that are difficult to access.

Painting

Powder coating of aluminium profiles is a solvent free and environmental friendly painting method. Conventional “wet” surface painting can be carried out using methods such as dipping, spraying, rolling or curtain coating. One advantage of “wet” painting is that many such paints have good adherence and the product can be formed after having been painted.

Screen printing

Screen printing is a method that is used to print on smooth, flat materials. The colour is printed direct on the part through a silk/gauze screen.

Tensile strength

The tensile strength specifies the maximum gross stress in N/mm2 which the material withstands before fracture during a tensile test.

Weld-less tube

The designation for coarse tubes that can be used to advantage instead of round bars, which decreases processing costs. Weld-less tubes are produces over a mandrel, which means they have no welded zones. A great number of weld-less tubes can be supplied from stock. Read more about rolled tubes and seamless tubes.

Yield strength

The yield strength specifies the tensile stress in N/mm2 that is needed to obtain a permanent elongation of 0.2%