Duralumin

Duralumin (also called duraluminum, duraluminium, duralum, duralium or dural) is the trade name of one of the earliest types of age-hardenable aluminium alloys. Its use as a trade name is obsolete, and today the term is mainly used to describe aluminium–copper alloys, designated as the 2000 series by the International Alloy Designation System (IADS).

In addition to aluminium, the main materials constituting duralumin are copper, manganese and magnesium. Composition of Duralumin are as follows:-

Duralumin was developed by the German metallurgist Alfred Wilm at Dürener Metallwerke AG.

In 1903, Wilm discovered that after quenching, an aluminium alloy containing 4% copper would slowly harden when left at room temperature for several days. Further improvements led to the introduction of duralumin in 1909. The name is obsolete today, and mainly used in popular science to describe the Al-Cu alloy system, or '2000' series, as designated by the International Alloy Designation System (IADS) originally created in 1970 by the Aluminum Association.

Its first use was in rigid airship frames eventually including all those of the "Great Airship" era of the 1920s and 1930s: the German passenger Zeppelins LZ 127 Graf Zeppelin, LZ 129 Hindenburg, LZ 130 Graf Zeppelin II, and U.S. Navy airships USS Los Angeles (ZR-3, ex-LZ 126), USS Akron (ZRS-4) and USS Macon (ZRS-5). Its composition and heat treatment were a wartime secret. With this new rip-resistant mixture, duralumin quickly spread throughout the aircraft industry in the early 1930s, where it was well suited to the new monocoque construction techniques that were being introduced at the same time. Duralumin also is popular for use in precision tools such as levels because of its light weight and strength.

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