Step 01
Billet heating
The cylindrical aluminium billet is heated in a furnace to 450–500 °C. At this temperature aluminium is soft enough to flow without cracking, but it does not melt.
450–500 °C
Process
What is aluminium extrusion?
Extrusion pushes a heated aluminium billet through a shaped steel die with a hydraulic press. The result is a profile with the same cross-section along its whole length. Scroll through the eight steps below on a 3D model of the press.
- Billet temperature
- 450–500 °C
- Dies
- 3000+
- Presses
- 5" + 6"
Eight steps from billet to profile
Step 02
Loading the container
The heated billet is loaded into the container waiting on the press axis. The container is preheated too, so the billet does not cool before pressure is applied.
Billet → container
Step 03
Ram pressure
The hydraulic main cylinder drives the ram forward. The dummy block on the ram tip upsets the billet inside the container; it fills the container wall and starts to flow towards the die.
5" and 6" presses
Step 04
Through the die
The compressed aluminium passes through the die opening and takes its shape. The cutaway view shows how the profile forms inside the container, die and die holder.
3000+ dies
Step 05
Profile exit and puller
The profile leaves the back of the die onto the run-out table. The puller grips its end and pulls at press speed, so the profile stays straight on the table.
Run-out table + puller
Step 06
Cooling
The hot profile is cooled on the run-out table by fan, water or spray, depending on alloy, section and required properties. The cooling rate sets mechanical properties and dimensional stability. T5 involves cooling after hot forming followed by artificial ageing; T6 involves solution heat treatment, quenching and artificial ageing.
Air / water
Step 07
Stretching and cutting
The profile is gripped at both ends and typically stretched by 0.5 to 3 percent, which straightens it and relieves internal stress. A saw then cuts it to the ordered length.
0.5–3 % stretch
Step 08
Ageing (T5/T6)
The cut profiles go into the ageing oven and are held for several hours, typically between 160 and 200 °C. T5 means cooling after hot forming followed by artificial ageing; T6 means solution heat treatment, quenching and artificial ageing. The cooling method depends on the alloy, section and required properties.
T5 / T6
Parts of the press line
What each part of the 3D model does in the line.
- Main cylinder
- The hydraulic cylinder that turns oil pressure into the force driving the ram. This is where press force is generated.
- Ram
- The piston driven by the main cylinder. It passes the force to the billet through the dummy block.
- Dummy block
- The disc between ram and billet. It upsets the billet inside the container and keeps the ram clear of the hot aluminium.
- Container
- The heated steel sleeve that holds the billet. It supports the billet from all sides under pressure.
- Billet
- The cylindrical aluminium log heated to 450–500 °C; the raw material of the profile.
- Die
- The steel disc whose opening defines the profile cross-section. Aluminium takes its shape as it passes through.
- Die holder
- The ring that holds the die in position opposite the container and passes the load to the platen.
- Platen
- The thick steel plate that carries the press force. Tie rods connect it to the rear platen.
- Run-out table
- The roller table the profile travels along after leaving the die.
- Puller
- The carriage that grips the profile end and pulls at press speed. It keeps the profile straight on the table.
- Cooling
- The cooling hood over the run-out table. Fan, water or spray cools the profile, depending on alloy, section and required properties.
- Stretcher
- The bench that grips both profile ends and stretches the profile in a controlled way. It straightens the profile and relieves stress.
- Saw
- The travelling saw that cuts the stretched profile to the ordered length.
- Ageing oven
- The oven where profiles are held at temperature for the T5 or T6 temper.
From your drawing to a profile
Send the cross-section and quantity of your profile, and we will assess manufacturability and the die it needs together.