Aluminum extrusion is an advanced manufacturing technique for achieving uniformly detailed parts of indeterminate length.
Aluminium extrusion is a production method in which aluminium is pushed, by use of pressure, through a mold with the desired shape. The material can be extruded in complex shapes. Several extrusion methods are possible, in which the shape complexity, surface quality, porosity, tolerances and the desired length play an important role in making the right choice.
- Complex cross-sectional shapes are possible.
- Products have an excellent surface finish.
- The production method is limited only to a cross-sectional shape. Other shapes can be offered with alternative production techniques.
In aluminum extrusion, bar material (full, flat, round or hexagonal bar) is pushed under compressive force through a die with the desired shape. Extrusion can be performed in two ways, either directly or indirectly, using either hot or cold aluminum.
Hot aluminum extrusion is performed at temperatures of 350 to 500 degrees Celsius. The advantage of hot extrusion is that it is easier to push the material through the die. The disadvantage is that lower tolerances are achieved. Cold aluminum extrusion is performed at room temperature. The advantages are that the aluminum gets a higher strength, better tolerances can be achieved and the extrusion gets a better surface quality. The disadvantage is that less complex shapes can be extruded.
In indirect extrusion, the die is pushed through the aluminum in the container. This method is also called backward extrusion. Indirect extrusion has the advantage of creating less friction forces between the press and the container, which guarantees a longer life for the machines. In addition, the aluminum formed is less likely to crack and there are fewer surface imperfections. The disadvantage of this method is that the length of the extrusion is limited.