Aircraft alloys

Composites of aluminium alloy with a thin cladding on one or both surfaces of a more anodic aluminium alloy or pure aluminium, enable sheet, plate and tube to be produced with special combinations of strength and corrosion resistance appropriate to service conditions. Although originally applied to high strength aircraft alloys, this principle of cladding is now utilised in several important industrial applications. 

McCaffrey. T.J. Combined Strength and Toughness Characterize New Aircraft Alloy/ Materials Processes. 47 (September. 1992),... 

Dealuminification. Recent investigations have shown the importance of the dealloying of S-phase (Al2CuMg) particles on the corrosion of aluminum aircraft alloys, specifically aluminum alloy 2024-T3. In 2024-T3, the S-phase particles represent approximately 60% of the particle population. These particles are of the order of 1 pm diameter, with a separation of the order of 5 pm representing an surface area fraction of 3%.56 The selective removal of aluminum and magnesium from these particles leaves behind a porous copper particle that becomes the preferential site for oxygen reduction.57, (Corcoran)5... 

Gabel, M.K. and Peterson, M.B., A Study of Parameters Which Affect Corrosion Between Solid Film Lubricants and Aircraft Alloys, ASLE Preprint No. 76-AM-6C-2. 

ARALL laminates, a family of hybrid composites consisting of aramid fibers bonded with epoxy between 0.3 mm thick aircraft alloy sheets, were introduced in the 1980s (53). The laminates have lower density than even the new Al—Li alloys and are gready superior to monolithic aluminum sheet in resisting the growth of fatigue cracks. ARALL laminates have been specified for aircraft stmcture which is subjected to cyclic tension loads (see Laminates). 

Summitt and Fink [41] developed an environmental corrosion severity classification system for steel aluminum, magnesium, and titanium aircraft alloys. The corrosion damage algorithm (CDA) is shown in Fig. 10.10. This classification takes into account either the distance from saltwater or moisture levels. When the CDA considers the moisture levels in an atmosphere, the values of the concentration of the pollutants are compared with those listed in the Working Environmental Corrosion Standards (WECS) [42],... 

Electrowinning of Other Metals. Magnesium, like aluminum, is a low-density metal and is also manufactured by electrolysis. The electrolysis of molten magnesium chloride (in the presence of other metal chlorides to lower the melting point) yields mj ne-sium at the cathode. The scale of ms nesium production is not as large as that of aluminum, amounting to several hundred thousand metric tons per year. Ms -nesium is used in aircraft alloys, flares, and chemical syntheses. 

Beryllimn Aircraft alloys, electrical controls, fluorescent lights or tubing for neon sign manidactiu e... 

We wish to concern ourselves with the popular latent catalyzed, rubber modified, epoxy film adhesives developed for low temperature bonding of the main aircraft alloys, i.e., 2024 and 7075, bare and clad, aluminum. The maximum service environment we shall consider is 60°C, 100% relative humidity. Similarly, let us consider the problems with realistic structural loads, following the common adage that any material called "structural should be capable of sustaining a constant stress which is about 25% of its failing stress. 

Continuous immersion test for high-strength aircraft alloys (Ref 37) aqueous solution containing 2% NaCl plus O.S% sodium chromate... 

---