Aluminum thicker than 0.008 but thinner than 0.25 inches is considered aluminum sheet. All aluminum used in the aerospace industry is an aluminum alloy to add strength, corrosion resistance and versatility. Copper, zinc, magnesium and silicon are common additives to the aluminum alloys used for a wide variety of manufacturing applications from cars and jets to spacecraft.
Aluminum sheet starts as aluminum plate, which started as as larger ingots of aluminum alloy. This ingot can be 6 feet wide, 20 feet long and 2 feet thick. These sheet ingots may weight in excess of 20 tons each and are preheated to help with the initial rolling process into the much thinner aluminum plate.
From Plate to Aluminum Sheet
Once formed into aluminum plate the material is further processed through additional rolling. This is done on a continuous mill to compress the plate to the desired thickness for the sheet and also to wind the thinner material into a coil.
Each coil is then further processed through cold rolling. This is typically done at room temperature or below the recrystallization temperature for the alloy. With aluminum this helps to achieve the strength setting this alloy apart for use in the aerospace industry.
Depending on the specific series and specific requirements for the aluminum sheet the coil may be pre-heated before cold rolling which can allow for a thinner, finer sheet.
Heat-treatable aluminum sheet may undergo further passes through the furnace to heat the aluminum alloy above specific temperatures. Then, through the cooling process, the overall strength of the alloy increases.
Factors to Consider
Depending on the type of aluminum alloy, and if it is heat treated or not, there are different factors to consider when choosing a particular type of aluminum sheet. Heat treated aluminum is often selected for heavy duty use where corrosion resistance, weldability and strength is paramount in choosing the specific alloy. 6061 aluminum is often the go-to option for these requirements.
For an aluminum sheet that is easy to machine and can withstand high-stress applications 2014 aluminum is a good selection. This is often used in aircraft structures for its resistance to fatigue as well as its corrosion resistance.
7075 aluminum alloy is an excellent choice for an easy to shape type of aluminum sheet. However, this is not as corrosion resistant as the other options so it is not often used in applications and environments where corrosion is a concern.
Choosing the right aluminum sheet for the job includes considering necessary machinability, strength and corrosion resistance. With a wide range of options available it won’t be difficult to find just the right alloy for any specifications.
With a large inventory of standard aluminum sheet alloys in stock Aerotech Alloys can supply everything you need for any size of job. To learn more about our products and value added services contact us at Aerotechalloys.com.