What is Extruded Aluminum Process
Extruded aluminum products play an important role in every area of our lives. So how is it manufactured? We can learn from the following steps.
Aluminum Bars
Aluminum rods are the billets for the extrusion process. Aluminum rods for extrusion can be solid or hollow, usually cylindrical, and the length is determined by the extrusion ingot barrel.
Extrusion
When the shape of the final product has been determined, the appropriate aluminum alloy has been selected, the extrusion die has been made, and the preparation for the actual extrusion process is complete. The aluminum bar and the extrusion tool are then preheated.
During the extruded aluminum process, the aluminum rods are originally solid but have been softened in the heating furnace. Aluminum alloys have a melting point of approximately 660°C. Typical heating temperatures for the extrusion process are generally greater than 375°C and, depending on the condition of the metal to be extruded, can be as high as 500°C.
Belows video shows aluminum extrusion process：
Applying Pressure
The actual extrusion process begins when the extrusion rod begins to apply pressure to the aluminum bar inside the ingot. Different hydraulic presses are designed for press forces ranging from 100 to 15,000 tons. Almost any pressure is possible.
This press force determines the size of the extruded product that the press can produce. Extruded product size is expressed in terms of the largest cross-sectional dimension of the product, or sometimes the diameter of the outer circle of the product.
Aluminum Extrusion Deformation
When extrusion begins, the aluminum bar is shortened and thickened by the reaction force of the die until the expansion of the bar is restrained by the walls of the ingot cylinder. Then, as the pressure continues to increase, the soft (still solid) metal has no place to flow. It begins to be extruded through the forming hole in the die and out the other end of the die, which forms the profile.
Processes after aluminum extrusion
Approximately 10% of the aluminum bar (including the bar skin) is left in the ingot cylinder. The extruded product is cut off from the die and the metal remaining in the ingot container is cleaned up and recycled.
After the product has left the die, the hot extruded product is then quenched, mechanically treated and aged.
Extrusion Speed
The speed depends on the alloy being extruded and the shape of the die discharge hole. Extruding complex shapes with hard alloys may be as slow as 1-2 feet per minute. Extruding simple shapes with soft alloys can be as fast as 180 feet per minute or even faster.
The length of the extruded product depends on the aluminum bar and the die exit hole, and up to 200 feet of product can be extruded in a single, uninterrupted extrusion. With the latest molding extrusions, the extruded product is placed on a slide table (the equivalent of a conveyor belt) as it leaves the extruder.
This Video from Hugh Aluminum shows whole process of extruded aluminum process：
Aging and Hardening
When the profile is extruded from the extruder, the profile is in a semi-solid state. However, it quickly becomes solid when it is cooled or quenched (either air or water cooled).
Non-heat-treatable reinforced aluminum alloys (e.g., those with magnesium or manganese additions) gain strength through natural aging and cold working.
Heat-treatable reinforced aluminum alloys (e.g., aluminum alloys with copper, zinc, magnesium + silicon) gain strength and hardness by heat treatments that affect the metallurgical structure of the alloy.
Summary
These are the instructions on how to manufacture extruded aluminum, and the factors to be noted for manufacturing.
Hugh Aluminum is an aluminum extrusion manufacturer based in China. We have bending, extrusion, powder coating, anodizing, CNC and polishing processing capabilities. We are 15 years experienced aluminum extrusion supplier and can offer you factory price and high quality products.
