Advantages of extruded aluminum
●Lightweight: Aluminum is about 1/3 the weight of iron, steel, copper or brass, making aluminum extrusions easier to handle, less expensive to ship, and an attractive material for use in applications where weight reduction is a priority such as transportation and other applications involving moving parts.
●Strong: Aluminum extrusions can be made as strong as needed for most applications and, due to the nature of the extrusion process, the strength can be concentrated where it is really needed by including varying wall thicknesses and internal reinforcement in the profile design. Cold-weather applications are particularly well served by extrusions, as aluminum becomes stronger as temperatures fall.
●High in strength-to-weight material: Aluminum extrusions' unique combination of high strength and low weight makes them ideal for applications like aerospace, truck trailer and bridges where load carrying is a key performance.
●Resilient: Aluminum combines strength with flexibility, and can flex under loads or spring back from the shock of impact, leading to the use of extruded components in automotive crash management systems.
●Corrosion resistant: Aluminum extrusions offer excellent corrosion resistance. They do not rust, and the aluminum surface is protected by its own naturally occurring oxide file, a protection that can be enhanced by anodizing or other finishing processes.
●Excellent thermal conductors: Based on weight and overall cost, aluminum conducts heat and cold better than other common METALS, making extrusion ideal for applications requiring heat exchangers or heat dissipation. Extrusion's design flexibility allows designers to optimize heat dissipation in housings and other components.
●Environmentally Friendly and highly recyclable : Aluminum does not pollute the environment. And aluminum has extremely high recyclability, and the performance of recycled aluminum is almost the same as primary aluminum.
The Extrusion process for aluminum profile
The aluminum extrusion process really begins with the design process, for it is the design of the product — based on its intended use — that determines many of the ultimate production parameters. Questions regarding machinability, finishing, and environment of use will lead to the choice of alloy to be extruded. The function of the profile will determine the design of its form and, hence, the design of the die that shapes it.
Once the design questions have been answered, the actual extrusion process begins with billet, the aluminum material from which profiles are extruded. The billet must be softened by heat prior to extrusion. The heated billet is placed into the extrusion press, a powerful hydraulic device wherein a ram pushes a dummy block that forces the softened metal through a precision opening, known as a die, to produce the desired shape.
This is a simple diagram of a typical horizontal hydraulic extrusion press; the direction of extrusion here is from left to right.
That is a simplified description of the process known as direct extrusion, which is the most common method in use today. Indirect extrusion is a similar process, but with some important differences. In the direct extrusion process, the die is stationary and the ram forces the alloy through the opening in the die. In the indirect process, the die is contained within the hollow ram, which moves into the stationary billet from one end, forcing the metal to flow into the ram, acquiring the shape of the die as it does so.
The extrusion process has been likened to squeezing toothpaste out of a tube. When pressure is applied at the closed end, the paste is forced to flow through the open end, accepting the round shape of the opening as it emerges. If the opening is flattened, the paste will emerge as a flat ribbon. Complex shapes can be produced by complex openings. Bakers, for example, use a collection of shaped nozzles to decorate cakes with fancy bands of icing. They’re producing extruded shapes.
As suggested by these toothpaste tubes, the shape of the extrusion (profile) is determined by the shape of the opening (die).
But you can’t make very many useful products out of toothpaste or icing and you can’t squeeze aluminum out of a tube with your fingers.
You can squeeze aluminum through a shaped opening, however, with the aid of a powerful hydraulic press, producing an incredible variety of useful products with almost any shape imaginable.
Deburring, Brushing, Graining, Sanding, Polishing, Abrasive blasting, Shot blasting, Glass bead blasting, Burnishing, Anodizing, Powder coating, Electrophoresis