Aluminum Extrusion

Summary

The aluminum extrusion process involves heating a cylindrical billet of aluminum to 900°F before applying pressure in a press to force it through a die, shaping it into a profile. The extrusions are then cooled, straightened, and cut to size. The final product undergoes aging, either naturally at room temperature or through controlled heating in an oven, to enhance strength and elasticity. The process concludes with the cleaning and inspection of the die for reuse. This method ensures the production of strong, high-quality aluminum profiles.

Takeaways

• 😀 The aluminum extrusion process begins with loading a die into the press, which has openings that shape the profile of the aluminum.
• 😀 Dies are preheated to prevent the aluminum from sticking to them during extrusion.
• 😀 The raw alloy used in extrusion is brought in the form of a solid cylindrical Billet, which can be up to 72 inches long.
• 😀 The Billet is heated to 900°F in a furnace, allowing it to become soft while maintaining its shape in solid form.
• 😀 Even after exiting the furnace at 900°F, the aluminum's color remains unchanged.
• 😀 Pressure is applied to the heated Billet in the press, causing the aluminum to squeeze through the die openings and form a profile.
• 😀 The extrusion is cooled either naturally or with air/water quenches to ensure proper metallurgical properties.
• 😀 The cooled extrusion is placed on a cooling table, where a stretcher is used to straighten and correct any twisting.
• 😀 A finished cut saw is used to cut the profile to a specified commercial length after cooling.
• 😀 The extrusions are prepared for aging, which strengthens them through natural or artificial aging processes.
• 😀 The die is cleaned of residual aluminum and inspected after each use to ensure it’s ready for future extrusion processes.

Q & A

What is the purpose of preheating the die in the aluminum extrusion process?

Preheating the die prevents the aluminum from sticking to the die during the extrusion process, ensuring smooth operation and accurate profiles.

What is the form of aluminum used at the beginning of the extrusion process?

The aluminum is used in the form of a billet, which is a solid cylindrical length of alloy.

At what temperature is the aluminum billet heated, and why?

The aluminum billet is heated to 900°F. This temperature softens the aluminum while maintaining its solid form, making it easier to extrude.

Why doesn’t the aluminum change color when it exits the heating furnace?

The aluminum doesn’t change color because it is still in its solid form, and the temperature only softens the metal, rather than melting or changing its color.

What happens to the aluminum when pressure is applied during the extrusion process?

When pressure is applied, the soft aluminum is crushed against the die, and as the pressure increases, the aluminum flows through the die openings, forming the desired profile.

How is the aluminum extrusion cooled after exiting the die?

The extrusion is cooled either naturally or through air or water quenching methods to ensure it retains its desired metallurgical properties.

What is the role of the stretcher in the extrusion process?

The stretcher is used after cooling to straighten the extrusion and correct any twisting that may have occurred during the extrusion process.

How is the aluminum extrusion cut to its final length?

After cooling and straightening, the extrusion is cut to its specified commercial length using a finished cut saw.

What is the purpose of the aging process in aluminum extrusion?

The aging process, either natural or artificial, strengthens the aluminum extrusion by altering its metallurgical structure to increase hardness, strength, and elasticity.

What happens to the die after the extrusion process is complete?

After the extrusion process, the die is removed from the press, cleaned of any residual aluminum, inspected, and prepared for the next use.