In today’s world, almost all of us, especially those in the Western world, rely on manufactured materials and constructions to make our day-to-day lives possible and comfortable. Aluminum is one of the most important metals used in building and architectural applications and in the restaurant, retail, automotive, OEM, telecommunication, bridge decking, marine, electronics, energy, and mass transit industries, to name a few.
Most applications and industries do not use aluminum in its raw form. It must first undergo certain preparatory processes before it is ready to play whatever its assigned role. One of the most widely used forms of this metal is known as extruded aluminum, which is to be the focus of this article. Read on to learn all about extruded aluminum as we highlight how it is made, where it comes from, what it is used for, and what makes it such a beneficial addition to our lives.
Let’s dive right in.
Before we get into extruded aluminum, we must start by exploring where we get this raw material from. Aluminum is a metallic element that makes up eight percent of the world’s rocks and soil. This makes it the third most abundant element on the planet.
While we can find aluminum in most types of clay, bauxite is the ore that is most workable and productive when obtaining aluminum. Bauxite ore is mined in many parts of the world, but Australia is the foremost supplier, producing more than a third of it. For every 4 pounds of bauxite, we can extract about 1 pound of aluminum, an efficient return ratio.
There are plenty of metals out there, but certain qualities make aluminum stand out as the most useful extruded metal we have right now. These qualities include:
We can recycle aluminum quite easily without losing any of its essential qualities. Moreover, the energy we expend when recycling aluminum is only 5 percent of what we need to produce it in its raw material form. In a world where we are all concerned about the impact of human activity on the earth’s ecology, this makes it a highly desirable material to work with.
Aluminum has a reflectance within the 200-400 nm range, one of the world’s highest. This exceeds the reflectance of silver and gold, which is why you can find aluminum film coatings used on the back of reflective mirrors rather than silver, which was traditionally used. Depending on the quality of its finish, aluminum can reflect about 90 percent of the light wavelengths spanning the visible spectrum.
As opposed to ferromagnetic metals such as steel, aluminum is paramagnetic. What this means is that aluminum will not acquire a magnetic charge whenever it is subjected to powerful magnetic fields, as other metals tend to. Because of this, aluminum is an excellent material for use in electrical enclosures, electronics, and machine components that emit high-power electromagnetic fields.
Aluminum has an exceptionally high impact strength and resilience thanks to its natural toughness. Sudden shocks and forces will not easily crack or weaken it, and it can flex under sustained mechanical pressure and dynamic loads. Such qualities make it especially useful in the construction and automotive industries, as buildings and vehicles can be made safer for human passengers and occupants without drastically increasing their weights.
Relative to steel, aluminum will retain its toughness in the face of exceedingly low temperatures, which makes most other metals brittle and prone to shattering. Aluminum will maintain its qualities across all extreme temperatures, whether high or low.
Even at room temperature, aluminum is easily formed and manipulated. Extrusion is not the only process that can be used to shape aluminum to our desired forms. Forging, stamping, drawing, and rolling are other widely used processes for aluminum work.
Aluminum can conduct heat twice as efficiently as brass and four times better than steel. The capacity of this metal to perform this function makes it one of the best materials for use in electrical components that need to operate under high temperatures or redirect heat from sensitive apparatus. Such components include heat shields, heat sinks, etc.
Aluminum has an electrical conductivity that is 615 that of copper. Because it is significantly less dense and cheaper than copper, this is increasingly making it many people’s first choice when manufacturing industrial products such as low-cost electricity transmission lines.
Compared to most metals, aluminum is highly corrosion-resistant because it tends to form oxide layers on its surface. Thus, it can be applied to outdoor surfaces and applications as a protective layer.
The most impactful quality of aluminum to the human industry is its high strength despite its relatively lightweight. Aluminum alloys can exceed the strength of steel by up to a factor of five. This property has made aluminum the most widely used metal in the automotive and aerospace industries.
Aluminum extrusion is a process that allows us to make use of aluminum in extraordinary ways. Thanks to the sophistication of the processes we use today and the inherent qualities of aluminum, we can create incredible products, tools, and applications. Extrusion is particularly useful when seeking to produce parts that have complex cross-sections.
Every extrusion process begins with forming the aluminum billets, which will eventually be fed into the extrusion machines. The aluminum will be refined from raw bauxite into aluminum oxide or alumina at this stage. In order to create pure aluminum, the oxygen is then separated from the alumina, and the resulting virgin aluminum is then smelted into the ingots that go into making up the billets.
Once the billets are delivered to the manufacturing plants, they will usually be heated to a certain temperature to increase their malleability and plasticity. The billets will then be loaded into cylindrical chambers with rams on one end and dies on the other. Subsequently, the rams will be driven hydraulically or mechanically to produce a compressive force on the billet, and this pressure will force the heated billet to flow through the die.
Various extrusion processes are differentiated by the method used to apply pressure to the billets, as outlined below:
Direct extrusion, the most commonly used method, involves pushing a billet against a die with a dummy block between the ram and the billet. The metal will flow in the same direction the ram pushes in with each travel or stroke.
Here, rather than have the ram press the billet against the die, the die will be pushed against the billet to affect the extrusion process. The die will be attached to a hollow ram, allowing the aluminum to flow opposite the ram’s movement. Because this method generates less friction, indirect extrusion is more energy efficient than direct extrusion but is still not as popular because it cannot generate as much compressive pressure. Because of this, indirect extrusion is only useful in producing extrudates with small cross-sections.
Here, a working fluid is introduced to minimize the friction levels generated during the extrusion process. The fluid completely covers the billet allowing for pressure transmission without direct contact with the extrusion chamber’s sides or the ram. Most extruders use a special type of oil with high heat tolerance. While this method offers the best of both worlds, it is still less popular than direct or indirect extrusion because of its lower throughput and increased operational complexity.
You can change its ductility, hardness, and strength by heating aluminum beyond its recrystallization temperature. Doing so can drastically reduce the pressure you need to apply to it to get the job done.
In this method, the extrusion process may be carried out at room temperature, although the continued pressurization will cause the metal to heat up. Cold extrusion is often preferred to hard extrusion because it results in lower oxidation, increased hardness, superior surface finish, tighter stress tolerances, and better surface finishes.
The qualities inherent in aluminum have made it one of the world’s most versatile and widely used metals. You will find it used in various industries across the world, and the reasons for its popularity include:
● Time-To-Market: Because producing aluminum tooling is much easier compared to most other metals, the manufacturing lead times involved when working with it are much shorter.
● Strength: Aluminum extrusions are valued for their high tensile strength and hardness. It can maintain this strength regardless of the weather and may even become stronger in colder climates.
● Recyclability: Aluminum extrudates are 100 percent recyclable and can be re-used indefinitely. Seventy-five percent of all the aluminum produced is still in active use today.
● Quality: Because extruded aluminum has no mechanical joints or welds, it has a consistent, uniform quality throughout its structure.
● Precision: Aluminum can conform to close tolerances and very tight spaces.
● Paramagnetism: Magnetic fields will not interfere with the performance of aluminum because it is a non-magnetic metal, making it ideal for use in machines such as magnet X-ray devices.
● Non-Toxicity: Aluminum can be used without the fear of contamination or toxicity, which is why you will find it in numerous household and building appliances.
● Malleability: Compared to most metals, aluminum is incredibly easy to extrude, machine, and form into complex shapes.
● Low Maintenance Requirements: Because aluminum is non-reactive in a normal environment, it will not degrade like most other metals, making it easy to maintain with minimal effort.
● Lightweight: Copper, brass, iron, and steel are up to three times as heavy as aluminum, making them much more difficult to handle. Aluminum makes for a much more manageable working metal.
● Heat Conduction: The conductivity of aluminum makes it an ideal metal for use in heat dispersal applications such as heat sinks, heat shields, and so on.
● Reflectivity: This is one of the most reflective metals used in industrial settings, and it will even be used as a reflective backing in mirrors instead of silver which had been the traditional choice.
● Expansivity: The linear expansion coefficient for aluminum is much higher than most metals, making it highly resistant to shearing effects and mechanical stress.
● Customization Capacity: Thanks to its ductility and malleability, aluminum is preferred in manufacturing because it can be shaped and molded into various forms and configurations.
● Corrosion Resistance: Aluminum can protect itself from the harmful effects of corrosion by forming a protective layer around itself when exposed to the open air.
● Conductivity: The capacity of aluminum to transmit electricity makes it an excellent transmitting wire, especially in situations where high-voltage electricity needs to be transmitted over long distances at the most cost-affordable prices.
● Aesthetic Value: You can anodize, buff, and polish aluminum to make it highly attractive without negatively impacting its utility and effectiveness.
● Affordability: The most attractive quality of aluminum is that it is significantly cheaper than other metals that perform comparable tasks, such as iron, steel, copper, etc.
Aluminum is one of the most remarkable metals we have on earth, thanks to its inherent qualities and abundance. It is easily accessible, cost-effective, highly conductive, non-magnetic, strong, durable, lightweight, and easily workable. With all the extruding processes available to manufacturers and producers, we can work aluminum into parts with complex cross-sections that can be used in countless industries, applications, and technologies.
These qualities and factors have made extruded aluminum one of the most popular worldwide materials. Still, you must be careful about who you choose to order your extruded aluminum parts from.
Not all producers have the skills, experience, equipment, and dedication to produce high-quality extruded aluminum consistently and affordably. The Guangdong JMA Aluminium Profile Factory has over 23 years of experience producing and distributing high-quality aluminum products to suppliers, retailers, and individual manufacturers all over the world. For all your aluminum needs, call us today. You won’t regret it!
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Nonferrous Metal Industrial Park, Xiaotang, Shishan Town, Nanhai District, Foshan City, Guangdong Province
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Gaobian Zhangbian Industrial Zone, Dali Guangyun Road, Nanhai District, Foshan City, Guangdong Province