99:, by Germany and the Allies during World War I. Duralumin was an aluminum-copper-magnesium alloy; it was originated in Germany and developed in the United States as Alloy 17S-T (2017-T4). It was utilized primarily as sheet and plate. Alloy 7075-T6 (70,000-psi yield strength), an Al-Zn-Mg-Cu alloy, was introduced in 1943. Since then, most aircraft structures have been specified in alloys of this type. The first aircraft designed in 7075-T6 was the Navy’s
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strength requirements are relatively low, the skin needs moderately high yield strength and hardness to minimize ground damage from stones, debris, mechanics’ tools, and general handling. Other primary factors involved in selecting an alloy for this application are corrosion resistance, cost, and appearance. Alloys 6061-T6 and alclad 2024-T3 are the primary choices.
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The alloys most used for extruded members are 2024-T4 for sections less than 0.125 in. thick and for general application, and 2014-T6 for thicker, more highly stressed sections. Alloy 6061-T6 has considerable application for extrusions requiring thin sections and excellent corrosion resistance. Alloy
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For low-stressed structure in light aircraft, alloys 3003-H12, H14, and H16; 5052-O, H32, H34, and H36; and 6061-T4 and T6 are sometimes employed. These alloys are also primary selections for fuel, lubricating oil, and hydraulic oil tanks, piping, and instrument tubing and brackets, especially where
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of aluminum alloys was developed initially to increase the corrosion resistance of 2017-T4 sheet and thus to reduce aluminum aircraft maintenance requirements. The coating on 2017 sheet - and later on 2024-T3 - consisted of commercial-purity aluminum metallurgically bonded to one or both surfaces of
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As the twentieth century progressed, aluminum became an essential metal in aircraft. The cylinder block of the engine that powered the Wright brothers’ plane at Kitty Hawk in 1903 was a one-piece casting in an aluminum alloy containing 8% copper; aluminum propeller blades appeared as early as 1907;
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welding is required. Alloys 3003, 6061, and 6951 are utilized extensively in brazed heat exchangers and hydraulic accessories. Recently developed alloys, such as 5086, 5454, 5456, 6070, and the new weldable aluminum-magnesium-zinc alloys, offer strength advantages over those previously mentioned.
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Sheet assembly of light aircraft is accomplished predominantly with rivets of alloys 2017-T4, 2117-T4, or 2024-T4. Self-tapping sheet metal screws are available in aluminum alloys, but cadmium-plated steel screws are employed more commonly to obtain higher shear strength and driveability. Alloy
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Light aircraft have airframes primarily of all-aluminum semi-monocoque construction, however, a few light planes have tubular truss load-carrying construction with fabric or aluminum skin, or both. Aluminum skin is normally of the minimum practical thickness: 0.015 to 0.025 in. Although design
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Casting technology has made great advances in the last decade. Time-honored alloys such as 355 and 356 have been modified to produce higher levels of strength and ductility. New alloys such as 354, A356, A357, 359 and Tens 50 were developed for premium-strength castings. The high strength is
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2014-T6 is the primary forging alloy, especially for landing gear and hydraulic cylinders. Alloy 6061-T6 and its forging counterpart 6151-T6 often are utilized in miscellaneous fittings for reasons of economy and increased corrosion performance, when the parts are not highly stressed.
103:. A higher-strength alloy in the same series, 7178-T6 (78,000-psi yield strength), was developed in 1951; it has not generally displaced 7075-T6, which has superior fracture toughness. Alloy 7178-T6 is used primarily in structural members where performance is critical under
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Alloys 356-T6 and A356-T6 are the primary casting alloys employed for brackets, bellcranks, pulleys, and various fittings. Wheels are produced in these alloys as permanent mold or sand castings. Die castings in alloy A380 also are satisfactory for wheels for light aircraft.
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of commercial-purity aluminum compared to alloy 2017 or 2024 in the T3 or T4 temper. When 7075-T6 and other Al-Zn-Mg-Cu alloys appeared, an aluminum-zinc cladding alloy 7072 was developed to provide a relative electrode potential sufficient to protect the new strong alloys.
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Skin sheet on light airplanes of recent design and construction generally is alclad 2024-T3. The internal structure comprises stringers, spars, bulkheads, chord members, and various attaching fittings made of aluminum extrusions, formed sheet, forgings, and castings.
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In 1916, L. Brequet designed a reconnaissance bomber that marked the initial use of aluminum in the working structure of an airplane. By war’s end, the Allies and
Germany employed aluminum alloys for the structural framework of fuselage and wing assemblies.
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is a common method of joining in both primary and secondary structures. Its selection is dependent on the design philosophy of the aircraft manufacturer. It has proven satisfactory in attaching stiffeners, such as hat sections to sheet, and face sheets to
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The improved welding processes and higher-strength weldable alloys developed during the past decade offer new possibilities for welded primary structures. For example, the weldability and strength of alloys 2219 and 7039, and the
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are used to join secondary structures, such as fairings, engine cowls, and doublers, to bulkheads and skins. Difficulties in quality control have resulted in low utilization of electric resistance welding for primary structure.
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2024-T4 with an anodic coating is standard for aluminum screws, bolts, and nuts made to military specifications. Alloy 6262-T9, however, is superior for nuts, because of its virtual immunity to stress-corrosion cracking.
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exterior skins. Maintenance requirements increased as a result, and these stimulated research and development programs seeking higher-strength alloys with improved resistance to corrosion without cladding.
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offers some economic and quality-control advantages for production joining, particularly for thin sheet. However, the method has not yet been developed extensively in the aerospace industry.
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of hydraulic control systems. The philosophy of some aircraft manufacturers still is to specify castings only in places where failure of the part cannot cause loss of the airplane.
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and low weld-joint efficiencies. Some of the alloys, such as 2024-T4, also have their corrosion resistance lowered in the heat-affected zone if left in the as-welded condition.
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However, the high-performance aircraft designed since 1945 have made extensive use of skin structures machined from thick plate and extrusions, precluding the use of
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has been the most demanding application for aluminum alloys; to chronicle the development of the high-strength alloys is also to record the development of airframes.
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Alloy 7079-T6 was introduced in the United States in 1954. In forged sections over 3 in. thick, it provides higher strength and greater transverse
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and aluminum covers, seats, cowlings, cast brackets, and similar parts were common by the beginning of the First World War.
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aluminum primary structures in airplanes are virtually nonexistent, because the high-strength alloys utilized have low
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and strength of X7005, open new avenues for design and manufacture of aircraft structures.
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than 7079-T6, is being developed for thick parts. Because it is relatively insensitive to
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rate, good strengths with low quenching stresses can be produced in thick sections.
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than 7075-T6. It now is available in sheet, plate, extrusions, and forgings.
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accompanied by enhanced structural integrity and performance reliability.
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traditionally have been used in nonstructural airplane hardware, such as
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in cable and hydraulic control systems permits the use of castings.
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Outer surface which covers much of its wings and fuselage
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301:Aircraft and Aerospace Applications: Part One
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279:Patch Repair of Corroded Aircraft Skin Areas
290:https://core.ac.uk/download/pdf/4407543.pdf
117:Alloy X7080-T7, with higher resistance to
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46:. The most commonly used materials are
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83:Alloys for airframe components
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54:with other metals, including
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136:Electrolytic protection
189:Electric resistance
170:, clips, ducts, and
319:Aircraft components
140:electrode potential
105:compressive loading
202:Ultrasonic welding
101:P2V patrol bomber
16:(Redirected from
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208:Adhesive bonding
119:stress corrosion
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223:weldability
172:wave guides
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313:Categories
266:References
180:Redundancy
162:brackets,
164:quadrants
123:quenching
112:ductility
93:Duralumin
60:magnesium
168:doublers
156:castings
129:Cladding
89:airframe
48:aluminum
44:fuselage
36:aircraft
70:History
160:pulley
148:alclad
64:copper
34:of an
40:wings
193:and
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62:and
56:zinc
50:and
42:and
32:skin
30:The
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