Aerospace Materials: A Historical Breakdown
From aluminum to thin steel sheets to combined metals, the aerospace industry has seen a lot of changes in manufacturing materials. This article will give you a brief historical breakdown of the different materials used in the aerospace manufacturing industry.
Aerospace Manufacturing: Early Years vs. Today
In earlier years, aluminum was the primary metal used in aircraft manufacturing since the metal was lightweight, relatively inexpensive, and very modern at the time. The metal was also very practical since it was malleable and ductile and easy to cut through. Almost 40 years ago, aluminum made up almost 70% of an aircraft, while composites and combined metals, which were relatively new materials at the time, made up about 7% of the craft. Aluminum came in thin sheet metal strips that were later welded and forged to make the fuselage, main engine components and other parts of the plane. Currently, the use of aluminum has drastically reduced to almost 20% because of the entry of combined metals, composites, and carbon fiber into the aerospace industry. In contrast to aluminum, these newer entries are very lightweight and strong and have broad applications in the more aesthetic and less functional parts of a plane like the paneling.
Aluminum still makes up a large portion of the engine and other vital components because it has one very important property. The thin metal strips strike the proper balance between light-weight and heat resistance, making it suitable for engine parts that generate a lot of heat but still light enough to make the craft fuel-efficient.
Steel and the Aerospace Industry
Steel has many diverse applications in a lot of industries, especially in aerospace manufacturing. The US spends about $30 million on steel metals annually, putting stainless steel amongst the metals with the most revenue in the country. The metal which comes in thin steel sheet batches is essential for many aerospace manufacturing companies for two reasons. First, it is resistant to oxidation even at high temperatures and corrosion, and second, they’ll maintain the same mechanical integrity even at low or high-temperature extremes. These attributes make thin steel sheet a very versatile material for a lot of aircraft parts depending on their grade.
AISI 304 and AISI 304L for example of austenitic steel is used to make fuel tanks while AISI 316 and AISI 321 are used for the more high-temperature parts like the exhaust, engine and other structural parts. For the more ambient parts, manufacturers prefer ferritic steel AISI 430 and Autentisic steel AISI 304 for their non-corrosive properties. Just like aluminum, steel comes in thin steel sheet batches that are molded into plane parts and welded into the plane.
New Materials in the Field
When it comes to metals, the term new may not actually mean a new entry. Some of these metals and their alloys have been around for decades, but engineers are finding new ways to combine them or form them to make them extremely cost-effective, light-weight, or durable hence the term new. Titanium 5553 is a perfect example of a relatively fresher entry into the aerospace scene because of its strength and resistance properties. Alcoa, which is also a new alloy, can be found in oxidizers and fuel tanks on both aircraft and space crafts.
The extensive use of metals in aerospace is only growing larger by the decade. Though the future of aerospace is uncertain, what is certain is things are only going to get better.