An Aluminum alloy is created when aluminum is mixed with other elements such as silicon or magnesium and other elements. There are many benefits to using alloyed metals as opposed to pure metals, as alloys allow us to extract the desirable properties and leave the undesirable ones behind. Aluminum by itself is great, but by integrating other elements into the mix, we have the opportunity to introduce various degrees of hardness, durability, ductility, tensile strength, and toughness.
Combined with its great strength, corrosion resistance, and other excellent qualities, you have a perfectly suited alloys for a multitude of uses in numerous end applications. Extrusion companies, such as Taber, offer manufacturers a wide variety of aluminum alloys to be specified by the customer depending on the applications in such industries as infrastructure, automotive, and appliances. This article dives into the topic of aluminum alloys, specifically the most predominant alloy family used for aluminum extrusions — 6000 series aluminum alloys.
In one of our previous blog posts, we defined an alloy as a mixture of metals, and in the case of aluminum alloys, the all alloys contain between 90 and 96% aluminum. Different alloy mixtures are classified into a series according to their unique characteristics. A four-digit number is used to identify alloy mixtures. The first digit of the number identifies the series (class) of alloy they belong to:
The 6000 series is an aluminum alloy family which contains magnesium and silicon as predominat alloying components. The remarkable properties of 6000 alloys are their extrudability, excellent strength, and high corrosion resistance. 6000 sereies alloys can also be thermally treated to enhance their strength properties. Extrusion products in the 6000 series are perfect choices for structural and architectural applications.
Taber offers a wide range of 6000 series aluminum alloys including 6061, 6063, 6082, 6005, and 6005A.
6061 is very popular for its characteristic toughness in medium- to high-strength applications. It is the most versatile and most used alloy of all the other 6000 series alloys because of its heat treatability and comparably easy machining and welding. 6061 alloys contain magnesium and silicon, which gives them a much greater corrosion resistance even on abraded surfaces.
Uses of this form of 6000 series alloy include applications from transportation, to infrastructure to more every day uses like fly fishing reels, firearm suppressors, non-flight critical aircraft components and automotive components. 6061 is available in many forms, including extrusion sheets, and forgings.
6063 is also an aluminum alloy with magnesium and silicon. First, it has lower magnesium and silicon levels, it is only half as strong as 6061, making it suited for applications where strength is not the fundamental consideration. Secondly, with the lower amounts of alloying components, achieving higher surface finish criteria is also possible.
Common uses for 6063 alloys include door and window frames, non-load-bearing posts, roofs, decorative structures, railings, furniture, parts for boats and motor vehicles, and electrical components such as conduit pipes, and tubes for irrigation systems. 6063 alloys are highly corrosion resistant which prevents environmental deterioration.
6082 alloy is generally known as “structural alloy” and provides one of the highest strengths of all the 6000 series aluminum alloys. It is a good alternative for engineers who don’t want to invest in the stronger 2xxx/7xxx series and also enables the ability to extrude more complex shapes not posible in 2xxx/7xxx alloys. 6082 is an alloy with silicon and manganese. It is commonly known for machining, and it also features excellent weldability, cold formability, and corrosion resistance. Its high amount of manganese allows it to control its grain structure, resulting in a stronger alloy that is perfect for general purpose applications that require an extra degree in strength and toughness. One drawback is that it is harder to form thin-walled, complicated extrusion shapes using 6082 alloys versus other alloys in the 6000 series family.
6082 is a relatively new alloy in North America and gaining wider acceptance, and in some applications, it can replace 6061 because of its higher strength capacity. It is typically used in highly stressed applications such as bridges, towers, trusses, structural automotive, and structural marine applications.
6005 and 6005A alloy
6005 alloy contains greater amounts of silicon which reduces its melting point and enhances its extrudability. 6005A, on the other hand, contains higher amounts of chromium which reduces its susceptibility to stress corrosion and improves its toughness. 6005A also contains extra manganese, which increases its strength and extrudability. Producing thin-walled and intricate extrusion can be difficult with 6005, but it still has better extrudability than 6082. Both 6005 and 6005A possess excellent bending capabilities and a better mill surface finish than 6061. These two alloys can both be welded or brazed easily using commercial methods, but the heat from welding can diminish the strength of the alloy. Both 6005 and 6005A offer excellent corrosion resistance, finishing characteristics, and respond well to standard anodizing methods creating clear, clear and color dye, and hardcoat finishes.
6005, 6005A , 6061 & 6082 have a fair amount of similarities and can be interchangeable in some situations, but 6005 and 6005A have much better extrusion qualities and mill surface finish than 6061 & 6082.
6005 and 6005A are typically used for applications that require intricate extrusions such as tubing for furniture, components for railways and busses, pipe, portable ladders, and applications where much greater strength from 6063 is needed, as well as in some marine applications.
Taber is considered a leader for specialty products such as 6000 series aluminum extrusions for use in many applications. 6000 alloys represent the vast majority used in the production of profiles for Taber Extrusions’ customers. Taber has focused on producing 6000 series alloys and has gained the expertise needed to meet these alloys’ rigorous manufacturing and processing requirements.
About Taber Extrusions:
Founded in 1973, Taber Extrusions originally pioneered a process for extruding rectangular billet, enabling the company to extrude solid profiles up to 31 inches wide or hollows up to 29 inches. Taber expanded with the purchase of an extrusion facility in Gulfport, MS, in 1995, which houses a new state-of-the-art cast house and two additional presses, microextrusion capabilities, and expanded the fabrication area multiple times.
Taber continues to extrude billet in a wide range of alloys and sizes and has developed its markets beyond the military since its inception to include aerospace, automotive, marine, infrastructure, and sporting goods, among many others. For these markets, the company supplies cast and extruded products in various soft and hard alloys.
Today, Taber Extrusions has completed the addition of in-house friction stir welding capabilities and carries on their offering of extruded aluminum components, value-added machining services, and raw material supply to the North American market – making them a vertically integrated supplier of FSW panels and assemblies never before seen in North America.
People today are becoming increasingly conscious of the energy they use and look for ways to be more conservative. For many, this draws them to use public transportation for its notable efficiency. But how can the public transportation itself become more efficient? The answer is aluminum. The use of aluminum extrusions in constructing public transport provides a number of benefits to a wide variety of vehicle types.
How do aluminum extrusions make public transport more efficient?
Aluminum is durable, light, and strong, making it the preferred material for public transportation. Some of the ways it increases efficiency are:
High strength-to-weight ratio: The efficiency of railways and subways depends greatly on trying to decrease weight in order to reduce friction. Aluminum extrusions are very lightweight yet still strong compared to other metals. This reduced weight also leads to…
Reduced fuel consumption: The lighter the vehicle, the less energy that is required to power it. Additionally, with a lighter vehicle structure, the vehicles can handle increased passenger and cargo weight. This significantly reduces the amount of fuel used per person (especially when compared with motor vehicles).
Long operating life and recyclable: Aluminum has the ability to withstand corrosion much better than many other metals. This reduces risk of rust or wear and tear on the public transport vehicles which means they can be in operation for longer periods of time. Also, because aluminum is malleable, any excess material from construction is fully recyclable.
Does it vary by type of transportation?
The previously described efficiencies are applicable to almost any public transport operation but there can be individual advantages depending on the vehicle type:
Trains and subway vehicles: Aluminum extrusions are used in the construction of both freight and passenger trains. For passenger trains, they are frequently made from a single aluminum extrusion that are the entire length of the car (75+ feet long). Individual parts are welded together with horizontal members around the doors and windows reinforcing the vehicle. With minimized parts and a simple assembly, the manufacturing becomes more efficient with a lighter and more aerodynamic final product.
Buses: Buses built from aluminum bodies are several hundred kilograms lighter than traditional construction. This increases the number of people transported per given maximum permitted weight, reducing costs for operating the bus. Because some buses travel great distance and often make frequent stops and starts, efficiency is extremely important.
Which alloys are used for public transportation?
The characteristics that make aluminum alloys ideal for public transport projects are that they are lightweight, strong, weldable, corrosion resistant, and easy to fabricate. The 5xxx and 6xxx aluminum series most closely fit this bill. Sheet metals commonly used are the 5052, 5083, 5086, 5454, and 6061. For extrusions, the 5083, 6061, and 7005 are commonly used. Because of the diversity of alloys in these series, there are extrusions available for almost any public transport project’s need.
Taber Extrusions knows what it takes to produce the top-quality extrusions required for public transportation projects. Our capability of producing very large aluminum shapes in our Russellville, AR facility with our rectangular and large round containers allows us to supply our customers with some of the heaviest solid profiles, and widest, most complex multi-void hollow profiles in the industry. Taber’s vertically integrated billet casting operations allows Taber to extrude a wide variety of alloys and profiles for the transport industry.
It is estimated that 56,000+ bridges are structurally deficient in America with an estimated $123 billion in rehab needed. The solution? The 6xxx Series Aluminum Alloys. Not only can they be used for emergency repairs but they can provide a long-term solution to this infrastructure problem with minimal maintenance required.Let us review what sets this alloy apart, its advantages, and the types of projects the alloy is best suited for.
What is an aluminum alloy?
Aluminum alloys are created by taking aluminum and adding elements, creating chemical compositions with enhanced properties. Once created, these compositions receive a 4-digit number with the first digit signifying a general series that characterizes its main alloying elements.
What does it mean when an alloy is a part of the 6xxx series
The main agents in the 6xxx series are silicon and magnesium in order to form magnesium silicide within the alloy. Alloy 6061 is the most commonly used of the series, typically used in truck and marine frames.
What are the advantages of the 6xxx aluminum alloys?
High Corrosion Resistance – 6xxx series aluminums can withstand abrasion, keeping their strength and durability in a variety of environments. This is one of the appeals to using it in infrastructure and architectural projects that hope to create structures with the intent of lasting decades. Whether its receiving harsh sunlight in the Nevada desert or nearly year round rain in Seattle, the alloy is able to hold up.
Extrudablitity – A unique feature of the 6xxx series is its extrudability. The ability to make specific, extruded parts from the alloy is another factor in why architectural and infrastructure members use this alloy. They typically require unusual, high-strength components and the power of extruded of 6xxx series is its ‘place-metal-where-you-need-it’ flexibility.
Heat treatable, weldable, flexible – 6061 is a highly weldable alloy, using tungsten insert gas welding or metal inert gas welding. After welding, the properties near the weld are those of 6061-O (a loss of strength of around 80%). However, MIG and TIG welded material can be heat treated again to bring the material back to the pre-welding temper. Another option may be Friction Stir Welding (FSW). With FSW, the profiles are joined together through the use of a specialized rotary machine tool. Although the material is heated and joined together through friction, the overall heat applied to the material is much lower and of shorter duration than MIG or TIG welding and the heat affected zone is much less and retains most of the original strength.
What are the applications of the 6xxx Series Aluminum Alloys?
It is this combination of advantages that make 6xxx Series Aluminum Alloys prime candidates for architectural and infrastructure projects. Such projects include:
Bridges or aluminum bridge decking: Extruded aluminums can be used to build traditional bridges or bridge decks can be pre-built in a modular fashion and moved to bridge sites. This method can limit the amount of time that bridges are under construction and save money in the long run.
Roof Structures: Typically implemented for arenas and gymnasiums, the 6063 or 6061 extruded tubes are used in large scale roofs with 5xxx alloy sheets covering them.
Pipelines: Because of their high corrosion resistance the 6xxx series is great for pipeline systems that have possibly acidic or dangerous materials flowing through them.
Automotive: Whether for a car, motorcycle, bus, or train, the 6xxx series is often used in the automotive industry for its high dent resistance and durability.
Taber Extrusions recognizes the hard work and precise engineering required for large-scale infrastructure projects. Capable of producing very large aluminum shapes with our exclusive 10” x 28” rectangular container along with our 16” and 20” round containers, we canconsistentlysupply our customers with some of the widest, most complex multi-void hollows in the industry. Taber produces their 6xxx series alloys in-house, and our recent investments in our casting and fabrication capabilities have poised Taber to be a great fit for any of your architectural and infrastructure needs… and a reliable partner for all aspects of your project.
The most predominant alloy used for aluminum extrusions is the 6xxx series.
6xxx series aluminum alloys are used across a wide variety of end use applications, including transportation applications with structural requirements to architectural projects with high surface finish requirements.
There is a 6xxx series alloy variant for most extruded profile end uses.
What is it about alloys from this series that make them so fitting for these types of projects? To understand series classification, you must first understand the science of an aluminum alloy.
An alloy is a mixture of metals. In the case of aluminum alloys, the mixture is typically 90-96% aluminum, with the remaining percentage filled by other elements, such as silicon. The beauty of alloys is that the interaction between aluminum and the added elements enhances the properties of aluminum (e.g., an alloy mixture may increase the strength of aluminum).
Alloy mixtures are classified into a series according to their unique characteristics. The qualifying criteria for the 6xxx series of aluminum alloys is the inclusion of magnesium and silicon in the mixture. Magnesium and silicon combine within the mix to form magnesium silicide.
The salient characteristics of 6xxx alloys are their extrudability, strength to withstand heat treatment, and exceptional corrosion resistance. The alloys in this series also have a great surface finish.
6xxx series aluminum alloys are ideal for architectural projects like bridge construction and repair, and other projects that will be repeatedly exposed to the elements given their resistance to atmospheric corrosion.
The corrosion resistance and surface finish also make 6xxx alloys ideal for framing windows and doors.
The 6xxx series is used widely for other applications, including consumer goods, piping and tubing, and electrical components.
One of the biggest advantages that we have is the capability to produce very big aluminum shapes, which means less work for the end user and ultimately, a less expensive product for everybody. Compared to projects that use steel, the use of aluminum is light weight and leads to higher load capacities, it has a high strength-to-weight ratio, can be recycled, and you don’t have to worry about rust!
Gradually, the country is starting to begin a national conversation about renovating our infrastructure. Traditionally, aluminum extrusions for infrastructure projects have been reserved for small projects like light posts, road signage, and guard rails. But developments in aluminum alloy technology, along with the large shape capability at Taber, we now have extrusions far more suited for large scale infrastructure projects like bridges, high-speed railways, and platforms such as helipads, ramps, flooring, and decking.
Aluminum Extrusions for Infrastructure
The high strength, weldability, and flexibility of aluminum, (particularly 6xxx series aluminum alloys, which Taber supplies in-house with the latest casting technology), can be relied on for infrastructure and architecture projects. As an added bonus its natural light weight makes delivery and installation a much easier, and often less expensive, process.
Aluminum shapes created for infrastructure also have the benefit of being low maintenance, due to high corrosion resistance and immunity to UV rays.
Potential applications include:
Aerospace (Helipads, etc.)
High speed / magnetic railways
Cranes and other construction needs
In a global market that is only becoming more competitive, the United States will need to turn its eyes back on its infrastructure if it hopes to retain its place near the top of the food chain.
Full service suppliers for aluminum products like Taber Extrusions are here to help with your infrastructure or public works project. Contact us, and tell us your needs – and we can lay the groundwork together.