Showing papers on "Aluminium alloy published in 1974"

Creep Rupture of Structures

Abstract: A study is made of the failure times of structural components which operate at temperatures sufficiently high to cause material deterioration due to creep rupture. Expressions are derived which give lower bounds on failure times and which take into consideration the different stress criteria known to affect rupture mechanisms. The formulae are used to predict failure times of a variety of components, and it is found convenient, from a practical point of view, to express the times in terms of an equivalent representative rupture stress. By using this stress, failure times are obtained directly from uniaxial stress rupture data. It is found in the examples studied that the values for the representative rupture stress are almost independent of the constants used to define the deformation and rupture processes. Experimental evidence supports the prediction of the theory; for example, copper bars in torsion show better rupture characteristics than bars of aluminium alloy. The position is reversed in notched tensile specimens, with the aluminium specimens showing better characteristics than those of copper. It can be deduced that it is the form of rupture mechanism which affects behaviour rather than ductility as might be expected, since the creep ductility of the aluminium alloy is much less than that for copper.

Method for reinforcing pistons

Abstract: A deposit of a reinforcing material is formed on an aluminium alloy piston by spraying one or more regions of the piston with a copper-based material from an electric-arc spray gun which produces molten particles of a heat content sufficient to produce an effective metallurgical interaction with the piston alloy so that the copper-based material is bonded to the region or regions of the piston.

Aluminium alloy conductor wire

Abstract: An aluminium alloy conductor wire consists of between 98.0 and 99.5 weight percent aluminium, between 0.3 and 1.0 (preferably 0.4 to 0.6) weight percent iron, between 0.08 and 1.0 (preferably 0.2 to 0.4) weight percent copper, a maximum of 0.15 (preferably 0.05 to 0.08) weight percent silicon, and trace quantities of conventional impurities. The conductor wire is especially suitable for use as a conductor of a telecommunication cable or as a component element of an overhead electric conductor.

Method for the manufacture of a compound casting

Abstract: A composite casting is produced by electrodepositing a wear resistance material onto a core, immersing the core in an aluminium melt and then casting an aluminium alloy around the core, before detaching the latter. The wear resistant layer may be given a roughened surface before immersing in the aluminium melt, by increasing the current density in the later stages of the depositing. The method may be used for casting light metal cylinders for internal combustion engines.

Foamed aluminium alloy - made by casting alloy contg. hydrogen and oxygen and permitting expansion on release of gases

Abstract: Porous (foamed) Al alloy mouldings, contg. an additive elements 0.3-5 (1.5-2.5) wt. % Mg, of which the apparent volume is 0.5-2.7 g/cc, have their porosity created by a conc. of H2 of 0.5-5.0 (1-3) cc/100 g, the partial pressure of H2 in the bubbles being somewhat below atmospheric which the mouldings contain 1000-5000 (2000-3000) ppm (by wt.) of O2. The matl. has a high energy absorption capacity, achieved in curshing while its thermal conductivity is markedly less than that of the metal in mass. The method does not involve use of metallic hydrides and other thermally decomposable cpds. The foam does not form till the moment of casting so that no worker is pressed for time during prepn. by the need to avoid untoward decompsn., etc. The prods. are used for building facade panels.

Process of forming colorless chromate film on Al, Al-alloy or Al-coated steel

Abstract: Colorless chromate film having good corrosion resistance and adhesive property on Aluminium, Aluminium alloy or Aluminium-coated steel when these materials are subjected to a pre-treatment stage wherein the material is rinsed with hot water after de-oiling and dried while the water film still lying on the surface is wiped by drawing rolls, a treatment stage wherein the material is processed with an aqueous solution of about 2 to 10g/l of CrO3, 0.05 to 1g/l Cr 3, 0.2 to 5g/l F , 0.01 to 5g/l of Ferricyanide and/or Ferrocyanide, 0.01 to 1g/l Al 3 and a post treatment stage wherein the material is processed with an aqueous solution containing water soluble copolymer of itaconic acid and acrylonitrile.

Surface treatment of aluminium and aluminium alloys

Abstract: The surface of aluminium or an aluminium alloy is treated by electrolytic deposition of a copper-indium alloy surface layer followed by the diffusion heat treatment of the coated surface. Electrolysis is carried out in a bath containing, in an aqueous alkaline solution, monovalent copper ions, trivalent indium ions, an alkali metal hydroxide, an alkali metal cyanide, an alkali metal gluconate, gluconic acid, and oxalic acid, and the heat treatment is carried out at between 120* and 155*C.

Complex stress relaxation of metals at elevated temperatures

Abstract: Four engineering metals have been investigated under complex stress relaxation conditions at elevated temperatures. These are a 0·24%C steel tested at 450°C, a commercially pure copper at 250° C, an aluminium alloy at 200°C, and a magnesium alloy at 50° and 20°C. The objects of the investigation were to determine whether simple tensile relaxation tests could provide an acceptable prediction of complex stress relaxation behaviour, and whether simple tensile creep data couldform the basis of a similar prediction of relaxation under complex stresses. Combined tension-torsion relaxation tests were made on thin-walled tubular specimens of each metal; these tests could be considered representative of complex stress conditions in general. The study has shown that tensile relaxation tests can provide a satisfactory prediction of complex stress relaxation. Alternatively, where only tensile primary creep data are available, the mechanical equations of state in association with tensile creep data lead to rea...

Composite sheet material, esp. for cooking utensils - consists of copper-contg. aluminium alloy clad with aluminium

Abstract: Composite material esp. in sheet form, for prodn. of cooking utensils, consists of a substrate of Cu-contg. Al alloy, clad, opt. on both sides, with a layer of Al or high Al alloy, esp. "3003 Alloy" (RTM). Pref. substrate alloy contains, by wt., 2-3 (2.2-3)% Cu, 0.4 (0.1-0.4)% Mn, 0.2-0.6 (0.3-0.6)% Mg, bal. Al, together with occasional elements and impurities not exceeding 0.3% Si, 0.7% Fe, 0.1% Cr, 0.25% Zr and 0.2% Ti. Cladding layer may be coated with a P.T.F.E. non-stick layer or with a porcelain enamel layer. Pref. substrate is clad on both sides, and one cladding layer is coated with P.T.F.E., while the other is coated with a porcelain enamel.

Die for manufacturing rods or wire of compound material with non-round cross-section

Abstract: A die for manufacturing rods of rectangular cross-section from a core of aluminium or an aluminium alloy and a casing of copper or a copper alloy by hydrostatic extrusion of a compound billet of such materials has a cup-shaped bottom which may be spherical, ellipsoidal, hyperbolic or parabolic in cross-section and a conical upper part. The bottom parts of the generatrices in axial section through the die form an angle which is between 120* and 180*, preferably between 150* and 170*, and a conical upper part has a cone angle between 40* and 120*.

Clad composite aluminium alloy - for use in heat exchangers with aq. medium

Abstract: The composite comprises an al alloy core contg. (in % wt) 0.5-3Mg, 0.3-1Mn, 0.1-0.3Cr, 0.001-0.003Ti, 0.001-0.3Si, 0.001-0.2Fe, 0.001-0.1Cu, 0.001-0.1Zn, bal. Al and an Al alloy cladding metallurgically bonded to >=1 surface of the core, contg. (in % wt.) 0.001-0.1Mg, 0.2-1.5Mn, 0.001-0.1Cr, 0.001-0.03Ti, 0.03-0.3Si, 0.001-0.05Cu, 0.001-0.4Zn, bal. Al. The cladding is pref. 0.001-0.1" thick. The core has high resistance to pitting corrosion and the cladding provides galvanic corrosion protection.

Fatigue properties of the Alclad Al-Cu-Mg-Si-Mn alloy

Abstract: Despite the wide use of Alclad aluminium alloy sheets in the aircraft industry, information on the effect of cladding on the mechanical strength of the strong alloy core is mainly limited to comparative fatigue testing of clad and unclad sheets, tested as plain specimens and subjected to constant-amplitude loadings. S/N curves obtained under such conditions were published by Smith, Brueggeman and Harwell for 24S-T3 material and by Shabalin for the D16T alloy (Russian specification). Both sets of data show that the soft cladding had a detrimental effect upon the fatigue strength of the strong alloy. Forrest has presented several comparative S/N curves which also show a reduction in the fatigue strength of the Alclad unnotched specimens compared with the bare alloy. Karlashov and Batov investigated the behaviour of cyclically-strained D16AT alloy (Russian specification), with particular reference to the nature of the mechanism of protection offered by pure aluminium. Although the core was electrochemi-cally protected against corrosion, intense damage occurred in the cladding layer.

High iron aluminum alloy

Abstract: OF THE DISCLOSURE An aluminium alloy conductor having an electrical conductivity of at least fifty-seven percent (57%) based on the International Annealed Copper Standard having increased ultimate elongation, ultimate tensile strength, creep strength, thermal stability, bendability and fatigue resistance when compared to conventional aluminum conductors. The aluminum alloy conductor can contain intermetallic constitutents consisting of: iron and aluminum and optionally silicon in varying ratios, in a concentration produced by the addition of from more than about 0.99 to about 2.50 weight percent iron to an alloy mass containing less than about 98.83 weight percent aluminum, from more than about 0.18 to about 0.40 weight percent silicon, and trace quantities of conventional impurities normally found within a commercial aluminum alloy.

Apparatus for Fatigue Tests in Vacuum at Low Temperatures

Abstract: Experimental apparatus is described for push‐pull fatigue tests between room temperature and 77 K and in a pressure range between 760 and 5 × 10−8 Torr. The specimen grips are cooled with liquid nitrogen. The variation of the temperature is less than ±2°C in the whole temperature range. To ensure good heat insulation, the loading rod is divided by a system of steel rings interspaced with glass balls. First results with an aluminium alloy are presented.

Creep strain measurements by foil gauges on aluminium alloys at 150C to 210C

Abstract: The use of foil gauges bonded with epoxy resin cements for the measurement of creep strains on aluminium alloy components at about 200C was investigated experimentally. Creep strains were measured on tubes in bending and sheet specimens in tension, both by strain gauges and also by proven extensometry and the results were compared. The response of the strain gauges was found to be satisfactory for continuous use at temperature to maximum times of about 500 hours.