Aluminum is a distinctive element with properties that make it especially valuable in applications requiring low weight, corrosion resistance, strength, and conductivity. Through extrusion, it can have any desired cross-section, which can include a variety of practical functionalities. This process is also less costly than molding or casting and can be completed much more quickly.
This article will go over the basics of aluminum extrusion, including its definition, process, and applications.
What Is Aluminum Extrusion?
Aluminum extrusion is a technique for transforming aluminum billets into objects with a defined cross-sectional profile. This process is accomplished by forcing the heated alloy material through a die.
Extrusion allows for the creation of both standard and complex shapes, which you can categorize into the following:
Solid: no enclosed openings or voids (rod, beam, or angle)
Hollow: with one or more openings or voids (square or rectangular tube)
Semi-hollow: with partially enclosed openings or voids (“C” channels with narrow gaps)
The Aluminum Extrusion Process
Extrusion typically occurs in direct or indirect presses with varying power levels. The basic process can be divided into five steps that manufacturers can adjust depending on the customer’s requirements.
Preheating the Steel Die and Aluminum Billet
The steel die is preheated to 450-500 ℃ before loading into the press to maximize its life and ensure even metal flow. Then, the billet — a solid, cylindrical block of aluminum alloy — is preheated to 400-500 ℃ to make it malleable enough for extrusion.
Loading the Billet Into the Extrusion Press Container
After preheating the billet, a lubricant or release agent is applied to it before being mechanically transferred to the extrusion press. The release agent is also used in the extrusion ram to prevent it from sticking to the billet.
Extruding the Heated Aluminum Billet
The heated aluminum billet is pushed through the tool openings, which are adjustable to create different shapes and sizes. In addition, liquid or gaseous nitrogen is incorporated and allowed to flow through the die sections to prevent the formation of oxides. This method produces an inert atmosphere and extends the die’s life.
Cooling the Extruded Component
Quick cooling follows the extrusion process, where the bars are subjected to a water bath to ensure uniform quenching of the heated aluminum. Moreover, the cooling process is carried out without delays to prevent material deformations.
Cutting and Stretching the Bar
The extruded bars are immediately cut to the specified interphase length after quenching. A puller then grabs the cut bars and places them on the runout table before going through a strengthening process. This stretches the bars and removes the internal tension to maintain their mechanical properties.
Applications of Custom Aluminum Extrusion
The following are some of the applications and industries that use the aluminum extrusion technique in their operations:
Architecture and Construction
Aluminum extrusions are used in various architecture and construction applications — from railings and ledges to building facades and bleachers. They are also ideal for making canopies with light but strong structures. In addition, extruded aluminum components are utilized in ladders, walls, and suspended ceilings.
Due to their excellent conductivity, extruded aluminum is frequently used for busbars and related electrical equipment. One example is the aluminum extruded with fins which is an ideal lightweight radiator or heat exchanger that can easily be mounted and colored. They are also applied in lighting applications and solar panel support structures.
Extruded bars and profiles are one of the most preferred materials for equipment like workbenches, inspection tables, and carts because they are lightweight, easy to cut, and cost-effective. They also have the added feature of being expandable, which means that if equipment needs to be modified, it can be done quickly.
Aluminum extrusions are used to manufacture products such as panels, engine blocks, and vehicle chassis. Their high strength-to-weight ratio enables the production of lightweight components, resulting in lighter vehicles. They also provide resistance to the environmental impact of moisture, corrosive forces from road salt, and temperature.
Need Custom Aluminum Extrusions? Partner With Superior Metal Shapes Now!
Superior Metal Shapes provides high-quality custom aluminum extrusions that exceed client expectations and meet the specifications of any project! We are also equipped with cutting-edge presses and technology, effectively accommodating a diverse range of extrusion works.
The machinability of aluminum alloys depends on the material’s properties and the process used. Compared to other metals, aluminum alloys are particularly well-suited to machining because they chip and shape easily. Aluminum is also highly accessible and affordable. For these reasons, aluminum alloys are a popular choice for machining applications.
Why Is Aluminum an Ideal Material for Machining?
In addition to its abundance and cost-effectiveness, aluminum provides a variety of benefits for machining applications. Combined with other metals and finishing processes, aluminum alloys are highly customizable to achieve nearly any desired properties. Here are some of the greatest benefits of machining with aluminum:
Good strength-to-weight ratio
High scrap value
Vast selection of custom finishes
Applications for Machined Aluminum by Classification
Pure aluminum is a very soft metal. Various alloying elements help make the metal into sheets, bars, and plates with enhanced physical properties suitable for specific applications. The Aluminum Association has categorized these properties into the following aluminum alloy series.
Aluminum Alloy Series 1xxx
Consisting of 99% aluminum and 1% silicon and iron, the 1xxx series has high ductility, low mechanical properties, and good electrical and thermal conductivity. Applications for these alloys typically include heat sinks and bus bars.
Aluminum Alloy Series 2xxx
Mainly alloyed with copper, the 2xxx series has excellent strength and workability. Although they lack sufficient corrosion resistance, weldability, and brazeability, these alloys can be heat-treated to produce better mechanical properties than mild steel. Aluminum alloy series 2xxx is a popular choice for home-built aircraft.
Aluminum Alloy Series 3xxx
Aluminum alloy series 3xxx is a general-purpose alloy not meant to be heat-treated. It provides moderate strength and good workability because manganese is its main alloying element.
Aluminum Alloy Series 4xxx
With the primary alloying element of silicon, the 4xxx series has a lower melting point without compromising toughness or malleability. Therefore, these alloys are ideal for welding wire. Adding an anodic oxide finish turns the metal dark gray, making it desirable for architectural applications.
Aluminum Alloy Series 5xxx
The 5xxx series alloys have manganese and magnesium as their main alloys, resulting in high tensile strength, excellent formability, and corrosion resistance. These properties make this alloy ideal for transportation and marine applications.
Aluminum Alloy Series 6xxx
With silicon and magnesium as primary alloying elements, the 6xxx series alloys are the most versatile aluminum alloys. Heat-treated, they provide superior formability, corrosion resistance, and medium strength, which make them perfect for custom extruded shapes in piping, consumer goods, electrical parts, and architectural components.
Aluminum Alloy Series 7xxx
Zinc, copper, chromium, and magnesium are the primarily alloying elements in this aluminum alloy. The 7xxx series can be heat-treated to produce high strength but limited machinability. Thus, they are typically used in mold-making for the aviation, defense, automotive, and marine industries.
Common Aluminum Alloys for Machining
Each aluminum series includes specific grades of aluminum alloys. Listed below are some of the most common types of aluminum alloys. Aluminum 2024, 6061, 7075, MIC 6, and 6082 are heat-treatable, while the others are not.
This aluminum and copper alloy has an excellent strength-to-weight ratio and fatigue resistance. Aluminum 2024 is often used in the aerospace, automotive, and transportation industries.
Aluminum 6061 is a versatile alloy made of magnesium and silicon. This alloy is usually machined to produce structural parts, valves, truck bodies, computer parts, and aircraft components.
This alloy is ductile, tough, and strong. Best used in highly stressed structural settings, Aluminum 7075 is ideal for aircraft products, sports equipment, and tooling.
Aluminum MIC 6
Aluminum MIC 6 is specifically developed to provide a high-tolerance, stable material for machining. Its stress-relieving, contaminant-free, and nonporous qualities make this lightweight metal ideal for electronic and laser applications.
This alloy is usually best for general-purpose applications that require an extra level of tensile strength. In fact, it’s the strongest 6xxx series alloy and is commonly found in infrastructures such as bridges and towers.
Alloyed with manganese, Aluminum 3003 is ideal for cooking equipment and other household goods.
Aluminum 5052 is resistant to saltwater, so it is perfect for marine applications. This alloy combines aluminum, magnesium, chromium, and other elements to strengthen the material against corrosion and improve its workability for other heavy-duty industries like energy and aerospace.
Aluminum Alloy Machining by Superior Metal Shapes
Superior Metal Shapes offers full-service aluminum machining services, from CNC machining to sawing to cutting to deburring. Secondary services include anodized painting, heavy etching, buffing, and military-grade finishing. Our ISO 9001 and AS9100 certified facility ensures the highest quality for every project. Contact us or request a quote to see how our capabilities can serve you.
Aluminum is a material that offers numerous benefits, making it a popular option for a wide range of applications. This metal features superior strength, lightweight nature, corrosion resistance, durability, and minimal maintenance requirements. Some applications specifically use extruded aluminum parts of various shapes. The aluminum extrusion process entails forcing the metal through a die that features a particular cross-sectional profile, similar to pushing toothpaste through a tube. Aluminum is considered one of the best materials to undergo extrusion because of its unique qualities and benefits.
In this blog, we’ll review how the aluminum extrusion process works, its advantages, the costs associated with it, and the extrusion capabilities at Superior Metal Shapes.
What Goes Into the Aluminum Extrusion Production Process?
During the extrusion process, several steps produce the aluminum part, from setup to surface treatment. Specifically, these steps include:
Preparation & Setup
Prior to extruding aluminum, operators need to load tooling plates into position and heat them to the appropriate temperature.
Following preparation and setup, the pressing process begins. This involves forcing a hydraulic ram into the chamber, which presses the heated and softened billet through the system’s tooling plates, also known as dies. As it travels through, the metal forms a stable profile shape that emerges from the other end until it sits on the runout table.
In some cases, parts may twist or curl if the profiles are poorly balanced, requiring stretching to return them to the desired shape.
Heating Process (Aging)
The next step involves stacking stock segments on carts that are slightly separated and heat treated, which is also known as “aging”. This lends added strength to the final product.
Some designs may require the system to cut ends at particular angles or lengths, mill sections of material away, or drill holes in the material.
Following production, certain surface treatments can be applied to the end product. This may entail painting, texturing, powder coating, or using a chemical finishing process known as anodizing.
Aluminum Extrusion Costs
Extruders who provide aluminum extrusion will vary greatly in their capabilities, equipment, and expertise, making it important to look for the right extruder and determine what is ideal to help minimize costs. Ultimately, the primary aluminum extrusion cost is the extrusion die, which could cost thousands of dollars. However, this cost is low when a large project relies on custom extrusion.
The lead times for aluminum extrusion are shorter, often taking less than a month. Combined with the main cost of the die, this advantage can help make the process even more affordable, allowing for cost-effective prototyping and revisions as required.
Keep in mind that tooling for bending machines and check fixtures contribute additional costs to aluminum extrusion, which is why it’s important to work with an extruder with ample experience to help avoid potential issues and increased costs.
Finally, order minimums could further add to the total cost of extrusion. A majority of extruders produce extrusions of a minimum size, often ranging from 1,000 to 2,000 pounds per extrusion. Some may also offer order charges as opposed to small batches. However, extruders may allow customers to negotiate order minimums if needed.
Other potential factors that could impact the price of aluminum extrusion processes include:
The alloys used for extrusion
Profile designs, including tubular, rectangular, or L, C, I, or custom profiles
Finishes used to protect or strengthen the final product
Affordable Custom Aluminum Extrusion from Superior Metal Shapes
At Superior Metal Shapes, we offer custom aluminum extrusion services to produce high quality parts at prices you can afford. To achieve this, our long list of capabilities includes:
Two 3.5-inch 850-ton presses and a 5.125-inch 900-ton press
Minimum order of 25 pounds
Maximum circle sizes of 4.75 inches
Tolerances within ± 0.002
A maximum weight per foot of 1.3 lbs. and a minimum of 0.015 lbs.
Extrusion for thin or complex custom shapes
Hollow and multi-void hollow shapes
Prototyping and product samples
Order fulfillment in as little as 3-5 weeks for many parts
Varied packaging and shipping options
Get Started on Custom Aluminum Extrusion Today
Aluminum extrusion is a cost-effective and invaluable service for producing many types of aluminum parts. If you would like to get started on your next project with Superior Metal Shapes, request a quote today for our services.