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40-448: First flown in 1923, the OL was a high-performance amphibian with a large single hull and stabilizing floats fitted underneath each lower wing. The landing gear was retractable by use of a hand crank in the cockpit, and the plane was equipped with a tailskid for operations on land. It had a tandem open cockpit for a crew of two. The aircraft could be flown from either cockpit, with a wheel control in

80-610: A crucial role in determining the mechanical properties of duralumin. Optimal aging conditions lead to the formation of finely dispersed precipitates, resulting in peak strength and hardness. Aluminium alloyed with copper (Al-Cu alloys), which can be precipitation hardened , are designated by the International Alloy Designation System as the 2000 series. Typical uses for wrought Al-Cu alloys include: German scientific literature openly published information about duralumin, its composition and heat treatment, before

120-610: A heavier-than-air aircraft structure occurred in 1916, when Hugo Junkers first introduced its use in the airframe of the Junkers J 3 , a single-engined monoplane "technology demonstrator" that marked the first use of the Junkers trademark duralumin corrugated skinning. The Junkers company completed only the covered wings and tubular fuselage framework of the J 3 before abandoning its development. The slightly later, solely IdFlieg -designated Junkers J.I armoured sesquiplane of 1917, known to

160-453: A man who works as a blacksmith plunges a screaming great axe blade or adze into cold water, treating it for temper, since this is the way steel is made strong, even so Cyclops' eye sizzled about the beam of the olive. However, it is not beyond doubt that the passage describes deliberate quench-hardening, rather than simply cooling. Likewise, there is a prospect that the Mahabharata refers to

200-463: A much harder structure known as martensite. Steels with this martensitic structure are often used in applications when the workpiece must be highly resistant to deformation, such as the cutting edge of blades. This is very efficient. The process of quenching is a progression, beginning with heating the sample. Most materials are heated to between 815 and 900 °C (1,499 and 1,652 °F), with careful attention paid to keeping temperatures throughout

240-488: A substance with an inverse solubility that therefore deposits on the object to slow the rate of cooling. Quenching can also be accomplished using inert gases, such as nitrogen and noble gases. Nitrogen is commonly used at greater than atmospheric pressure ranging up to 20 bar absolute. Helium is also used because its thermal capacity is greater than nitrogen. Alternatively, argon can be used; however, its density requires significantly more energy to move, and its thermal capacity

280-421: A tank in the fuselage was cooled by passing through a spiral copper tube exposed to the slipstream on top of the cowling. The fuel tanks were mounted inside the hull, with a 140-gallon (530-liter) gasoline tank under the wings, and a reserve 60-gallon (230-liter) gasoline- benzol tank between the cockpits. Total fuel capacity provided for roughly ten hours of flight. A number of variants were introduced for both

320-454: A uniform and lamellar (or layered) pearlitic grain structure. This is a mixture of ferrite and cementite formed when steel or cast iron are manufactured and cooled at a slow rate. Pearlite is not an ideal material for many common applications of steel alloys as it is quite soft. By heating pearlite past its eutectoid transition temperature of 727 °C and then rapidly cooling, some of the material's crystal structure can be transformed into

360-617: A “Duralinox” model that became an instant classic among cyclists. The Vitus 979 was the first production aluminium frameset whose thin-wall 5083/5086 tubing was slip-fit and then glued together using a dry heat-activated epoxy. The result was an extremely lightweight but very durable frameset. Production of the Vitus 979 continued until 1992. In 2011, BBS Automotive made the RI-D, the world's first production automobile wheel made of duralumin. The company has since made other wheels of duralumin also, such as

400-403: Is a trade name for one of the earliest types of age-hardenable aluminium–copper alloys . The term is a combination of Dürener and aluminium . Its use as a trade name is obsolete. Today the term mainly refers to aluminium-copper alloys, designated as the 2000 series by the international alloy designation system (IADS), as with 2014 and 2024 alloys used in airframe fabrication. Duralumin

440-524: Is below the boiling point of the liquid. There is evidence of the use of quenching processes by blacksmiths stretching back into the middle of the Iron Age , but little detailed information exists related to the development of these techniques and the procedures employed by early smiths. Although early ironworkers must have swiftly noticed that processes of cooling could affect the strength and brittleness of iron, and it can be claimed that heat treatment of steel

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480-420: Is desired, but there is a small chance that it may cause distortion and tiny cracking. When hardness can be sacrificed, mineral oils are often used. These oil-based fluids often oxidize and form sludge during quenching, which consequently lowers the efficiency of the process. The cooling rate of oil is much less than water. Intermediate rates between water and oil can be obtained with a purpose-formulated quenchant,

520-450: Is done by heating the material to a certain temperature, depending on the material. This produces a harder material by either surface hardening or through-hardening varying on the rate at which the material is cooled. The material is then often tempered to reduce the brittleness that may increase from the quench hardening process. Items that may be quenched include gears, shafts, and wear blocks. Before hardening, cast steels and iron are of

560-433: Is important that the temperature throughout the sample remains as uniform as possible during soaking. Once the workpiece has finished soaking, it moves on to the cooling step. During this step, the part is submerged into some kind of quenching fluid; different quenching fluids can have a significant effect on the final characteristics of a quenched part. Water is one of the most efficient quenching media where maximum hardness

600-455: Is less than the alternatives. To minimize distortion in the workpiece, long cylindrical workpieces are quenched vertically; flat workpieces are quenched on the edge; and thick sections should enter the bath first. To prevent steam bubbles the bath is agitated. Often, after quenching, an iron or steel alloy will be excessively hard and brittle due to an overabundance of martensite. In these cases, another heat treatment technique known as tempering

640-469: Is performed on the quenched material to increase the toughness of iron -based alloys . Tempering is usually performed after hardening , to reduce some of the excess hardness , and is done by heating the metal to some temperature below the critical point for a certain period of time, then allowing it to cool in still air. Heat is removed in three particular stages: Stage A: Vapor bubbles formed over metal and starts cooling During this stage, due to

680-450: Is relatively soft and ductile. Solution Annealing: Duralumin undergoes solution annealing, a high-temperature heat treatment process that dissolves the alloying elements into the aluminium matrix, creating a homogeneous solid solution. Quenching: Rapid cooling (quenching) after solution annealing freezes the high-temperature solid solution, preventing the precipitation of strengthening phases. Aging (Precipitation Hardening): During aging,

720-462: The Leidenfrost effect , the object is fully surrounded by vapor which insulates it from the rest of the liquid. Stage B: Vapor-transport cooling Once the temperature has dropped enough, the vapor layer will destabilize and the liquid will be able to fully contact the object and heat will be removed much more quickly. Stage C: Liquid cooling This stage occurs when the temperature of the object

760-745: The "Great Airship" era of the 1920s and 1930s: the British-built R100 , the German passenger Zeppelins LZ 127 Graf Zeppelin , LZ 129 Hindenburg , LZ 130 Graf Zeppelin II , and the U.S. Navy airships USS Los Angeles (ZR-3, ex-LZ 126) , USS Akron (ZRS-4) and USS Macon (ZRS-5) . Duralumin was used to manufacture bicycle components and framesets from the 1930s to 1990s. Several companies in Saint-Étienne, France stood out for their early, innovative adoption of duralumin: in 1932, Verot et Perrin developed

800-718: The Army and the Navy. During later production, the company merged with the Keystone Aircraft Corporation . The Loening OA-1A "San Francisco" is on display at the Steven F. Udvar-Hazy Center of the National Air and Space Museum in Chantilly, Virginia . The San Francisco took part in the 1926-1927 Pan-American Goodwill Flight through Mexico, Central, and South America. It was donated to

840-560: The RZ-D. Quenching In materials science , quenching is the rapid cooling of a workpiece in water, gas, oil, polymer, air, or other fluids to obtain certain material properties . A type of heat treating , quenching prevents undesired low-temperature processes, such as phase transformations, from occurring. It does this by reducing the window of time during which these undesired reactions are both thermodynamically favorable and kinetically accessible; for instance, quenching can reduce

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880-914: The Smithsonian Institution in 1927 and restored in 1964-1965. It was previously on loan to the National Museum of the United States Air Force in Dayton, Ohio from 1977 to 2006. Data from The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 2376 General characteristics Performance Related development Aircraft of comparable role, configuration, and era Related lists [REDACTED] Media related to Loening OL at Wikimedia Commons Duralumin Duralumin (also called duraluminum , duraluminium , duralum , dural(l)ium , or dural )

920-435: The crystal grain size of both metallic and plastic materials, increasing their hardness. In metallurgy , quenching is most commonly used to harden steel by inducing a martensite transformation, where the steel must be rapidly cooled through its eutectoid point, the temperature at which austenite becomes unstable. Rapid cooling prevents the formation of cementite structure, instead forcibly dissolving carbon atoms in

960-490: The factory as the Junkers J 4, had its all-metal wings and horizontal stabilizer made in the same manner as the J 3's wings had been, like the experimental and airworthy all-duralumin Junkers J 7 single-seat fighter design, which led to the Junkers D.I low-wing monoplane fighter, introducing all-duralumin aircraft structural technology to German military aviation in 1918. Its first use in aerostatic airframes came in rigid airship frames, eventually including all those of

1000-468: The ferrite lattice. In steel alloyed with metals such as nickel and manganese , the eutectoid temperature becomes much lower, but the kinetic barriers to phase transformation remain the same. This allows quenching to start at a lower temperature, making the process much easier. High-speed steel also has added tungsten , which serves to raise kinetic barriers, which, among other effects, gives material properties (hardness and abrasion resistance) as though

1040-906: The first light alloy crank arms; in 1934, Haubtmann released a complete crankset; from 1935 on, Duralumin freewheels, derailleurs , pedals, brakes and handlebars were manufactured by several companies. Complete framesets followed quickly, including those manufactured by: Mercier (and Aviac and other licensees) with their popular Meca Dural family of models, the Pelissier brothers and their race-worthy La Perle models, and Nicolas Barra and his exquisite mid-twentieth century “Barralumin” creations. Other names that come up here also included: Pierre Caminade, with his beautiful Caminargent creations and their exotic octagonal tubing, and also Gnome et Rhône , with its deep heritage as an aircraft engine manufacturer that also diversified into motorcycles, velomotors and bicycles after World War Two. Mitsubishi Heavy Industries , which

1080-410: The forward cockpit and a removable stick control in the rear. Navigation and engine instruments were located in the forward cockpit. The hull was built of Duralumin on a wooden frame, with five watertight compartments connected through a selector switch to a bilge pump in the rear cockpit. Plugs in the bottom of each compartment permitted drainage on the ground. The fuselage was constructed on top of

1120-460: The hull. The aircraft was strength-tested at Columbia University . The United States Army Air Corps ordered four prototypes as the XCOA-1 , powered by a 400-hp Liberty V-1650-1 engine mounted inverted for clearance of the three-bladed variable-pitch steel propeller . The engine came with a fire suppression sprinkler system and was encased in a streamlined cowling to protect it from sea spray. Oil from

1160-470: The introduction of duralumin in 1909. The name, originally a trade mark of Dürener Metallwerke AG which acquired Wilm's patents and commercialized the material, is mainly used in pop-science to describe all Al-Cu alloys system, or '2000' series, as designated through the international alloy designation system originally created in 1970 by the Aluminum Association . In addition to aluminium ,

1200-488: The main materials in duralumin are copper , manganese and magnesium . For instance, Duraluminium 2024 consists of 91-95% aluminium, 3.8-4.9% copper, 1.2-1.8% magnesium, 0.3-0.9% manganese, <0.5% iron, <0.5% silicon, <0.25% zinc, <0.15% titanium, <0.10% chromium and no more than 0.15% of other elements together. Although the addition of copper improves strength, it also makes these alloys susceptible to corrosion . Corrosion resistance can be greatly enhanced by

1240-545: The metallurgical bonding of a high-purity aluminium surface layer, referred to as alclad -duralum. Alclad materials are commonly used in the aircraft industry to this day. Duralumin's remarkable strength and durability stem from its unique microstructure, which is significantly influenced by heat treatment processes. Solid Solution: After initial solidification, duralumin exists as a single-phase solid solution, primarily composed of aluminium atoms with dispersed copper, magnesium, and other alloying elements. This initial state

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1280-478: The oil-quenching of iron arrowheads, but the evidence is problematic. Pliny the Elder addressed the topic of quenchants, distinguishing the water of different rivers. Chapters 18-21 of the twelfth-century De diversis artis by Theophilus Presbyter mentions quenching, recommending amongst other things that 'tools are also given a harder tempering in the urine of a small, red-headed boy than in ordinary water'. One of

1320-486: The outbreak of World War I in 1914. Despite this, use of the alloy outside Germany did not occur until after fighting ended in 1918. Reports of German use during World War I, even in technical journals such as Flight , could still mis-identify its key alloying component as magnesium rather than copper. Engineers in the UK showed little interest in duralumin until after the war. The earliest known attempt to use duralumin for

1360-481: The quenching is slower or interrupted, which also allows pearlite to form and results in a less brittle product. The earliest examples of quenched steel may come from ancient Mesopotamia, with a relatively secure example of a fourth-century BC quench-hardened chisel from Al Mina in Turkey. Book 9, lines 389-94 of Homer's Odyssey is widely cited as an early, possibly the first, written reference to quenching: as when

1400-449: The supersaturated solid solution becomes unstable. Fine precipitates, such as CuAl2 and Mg2Si, form within the aluminum matrix. These precipitates act as obstacles to dislocation movement, significantly increasing the alloy's strength and hardness. The final microstructure of duralumin consists of a predominantly aluminium matrix dispersed fine precipitates (CuAl2, Mg2Si) Grain boundaries. The size, distribution, and type of precipitates play

1440-529: The workpiece had been cooled more rapidly than it really has. Even cooling such alloys slowly in the air has most of the desired effects of quenching; high-speed steel weakens much less from heat cycling due to high-speed cutting. Extremely rapid cooling can prevent the formation of all crystal structures, resulting in amorphous metal or "metallic glass". Quench hardening is a mechanical process in which steel and cast iron alloys are strengthened and hardened. These metals consist of ferrous metals and alloys. This

1480-401: The workpiece uniform. Minimizing uneven heating and overheating is key to imparting desired material properties. The second step in the quenching process is soaking. Workpieces can be soaked in air (air furnace), a liquid bath, or a vacuum. The recommended time allocation in salt or lead baths is up to 6 minutes. Soaking times can range a little higher within a vacuum. As in the heating step, it

1520-820: Was developed in 1909 in Germany. Duralumin is known for its strength and hardness, making it suitable for various applications, especially in the aviation and aerospace industry. However, it is susceptible to corrosion, which can be mitigated by using alclad-duralum materials. Duralumin was developed by the German metallurgist Alfred Wilm at private military-industrial laboratory Zentralstelle für wissenschaftlich-technische Untersuchungen  [ de ] (Center for Scientific-Technical Research) in Neubabelsberg . In 1903, Wilm discovered that after quenching , an aluminium alloy containing 4% copper would harden when left at room temperature for several days. Further improvements led to

1560-529: Was known in the Old World from the late second millennium BC, it is hard to identify deliberate uses of quenching archaeologically. Moreover, it appears that, at least in Europe, "quenching and tempering separately do not seem to have become common until the 15th century"; it is helpful to distinguish between "full quenching" of steel, where the quenching is so rapid that only martensite forms, and "slack quenching", where

1600-507: Was prohibited from producing aircraft during the American occupation of Japan, manufactured the “cross” bicycle out of surplus wartime duralumin in 1946. The “cross” was designed by Kiro Honjo , a former aircraft designer responsible for the Mitsubishi G4M . Duralumin use in bicycle manufacturing faded in the 1970s and 1980s. Vitus nonetheless released the venerable “979” frameset in 1979,

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