Aluminum is renowned for its tremendous versatility, making it an in-demand material for manufacturers in pretty much every industry. Of the many applications and processes aluminum is well suited for, one of the most popular is rolling aluminum sheet and plate. Because there is a demand for all manner of shapes and sizes when it comes to rolled sheet and plate, aluminum has an advantage over most other materials and is widely used in rolling applications.
What exactly do we mean by rolling? In metalworking, rolling is a process that involves metal being passed through rolls that flatten out the material and give it a uniform thickness. It’s very similar to a baker using a rolling pin to flatten dough. Practically speaking, there are two main types of rolling, hot rolling, when the metal is hotter than its recrystallization temperature, and cold rolling, when it is cooler than its recrystallization temperature.
In fact, hot rolling processes more metal than any other manufacturing process, while cold rolling processes more metal than any other cold working process. There are many categories of rolling, such as ring rolling, roll bending, roll forming, profile rolling, and controlled rolling, all of which have their own unique attributes and effects.
Why is Aluminum Well Suited for Rolling?
Among the many advantages of aluminum, perhaps none is as significant as aluminum’s superior strength to weight ratio. Many aluminum alloys match or even surpass the strength of steel, yet it weighs only a third as much. This unparalleled strength means that aluminum can be rolled extremely thin while retaining its integrity.
Other advantages of aluminum include its cryo-tolerance. Aluminum can withstand much lower temperatures than other materials. Where metals such as steel and titanium will become brittle in cold temperatures, aluminum becomes even stronger.
Of course, one of the most desirable properties of aluminum is its extreme corrosion resistance. Depending on the alloy, aluminum can be deployed in extremely corrosive environments, such as for marine applications. This is due to aluminum’s ability to naturally form a transparent oxide film that protects it from the elements and actually gives aluminum the ability to heal itself.
Aluminum is also joinable (meaning it can be welded or bonded), reflective, and a good conductor of heat and electricity. Moreover, aluminum has many environmentally friendly attributes, including the fact that it is highly recyclable. It is also non-toxic, non-combustible, and, thanks to its versatility and lightweight, is cheaper to transport and helps to reduce energy consumption.
All of these advantages make aluminum a premium choice for rolling sheet and plate.
How Does the Rolling Process Work?
To roll aluminum plate, you need preheated aluminum sheet ingots that weigh as much as or more than twenty tons. A normal ingot for this process might be six feet wide, twenty feet long, and two feet thick. The metal is heated to the proper rolling temperature and then rolled back and forth until it is flattened to a few inches thick. Depending upon the desired properties of the sheet, the slab might then be cold rolled or heat-treated as necessary. Following the temperature treatment, the final sheet is produced and trimmed to its desired size.
When sheet or foil is wanted, further rolling will be necessary. In this case, the slab is rolled in a continuous mill and then wound into an aluminum coil. The distinction between them is that plate is the term used for flat metal that is more than 3 millimeters thick, while sheet refers to metal that is less than 3 millimeters thick. Foil has a thickness that is less than .15 millimeters.
In addition to the above, rolling mills can also different sorts of cages in order to produce various shapes. The initial billet, whether its round or square, is deformed in order to produce material with a smaller cross-section dimension and geometry. The various processes include roll bending, which results in a cylindrical shaped final product, and roll forming, a bending process that involves a long metal strip being passed through consecutive rolls to produce the desired cross-section profile.
What Applications Rely on Aluminum Sheet and Plate Rolling?
Because aluminum sheet is so versatile, it can be used in countless applications. This is due to the fact that it is receptive to being shaped, finished, and fabricated in all manner of ways, not to mention the great variety of alloys that are available. Sheet can have many different surfaces, such as painted, polished, coated, laminated, anodized, etched, or textured. As for machining, aluminum sheet can be sheared, sawed, or drilled, or it can be formed via bending, corrugation, or stamping. Sheet can also be joined with other materials through a variety of processes, including riveting, bolting, clinching, brazing, soldering, bonding, or welding.
Some of the many applications for aluminum sheet include beverage and food cans, cooking utensils, awnings, Venetian blinds, siding, roofing, gutters, street signs, license plates, heat exchangers, automobile parts, vehicle panels, boat hulls, and aircraft bodies.
When it comes to the much thicker aluminum plate, the material will often be used to cut out or machine aluminum parts, for instance for the ribbed wing plates of aircraft. Other applications include railroad gondola, tank cars, battle armor, large ship structures, offshore oilrigs, storage tanks, and spacecraft components.
As for aluminum foil, applications include food packaging, pharmaceutical packaging, laminated vapor barriers, artificial Christmas trees, sound diaphragms, and adhesive-bonded structural honeycomb.
With so many options, it can be difficult to know exactly what type of sheet or plate is required for any given application. Clinton Aluminum keeps a wide variety of sheet and plate in stock made from the most popular and desirable aluminum alloys. Because Clinton has the ability to process nearly any piece of metal, we make ideal partners for manufacturers of any size and scope.
Our goal is to be more than just a materials supplier, however. Our experienced and dedicated technical professionals pride themselves on their ability to help our customers through every step of the production process. Contact us today to learn more about our rolled aluminum sheet and plate offerings.