Showing papers on "Aluminium alloy published in 1968"

An experimental study of the effect of the prestraining history on the yield surfaces of an aluminium alloy

Abstract: Experimental results for fifty-six specimens of an aluminium alloy are presented in a study of the effect of the prestraining path on the shape of the yield surfaces. A special experimental technique has been applied, consisting of cutting out flat specimens from the prestrained sheet material. Experimental results show that if two various loading paths have different initial sectors and a common final sector, the influence of these initial sectors on the yield surface is the smaller the longer is the final common sector. A theoretical analysis of that problem on the basis of the kinematic workhardening rule is also presented.

Process for preparing a presensitized photolithographic printing plate

Abstract: PROCESS FOR PRODUCING A PRESENSITISED LITHOGRAPHIC PRINTING PLATE COMPRISING (I) ANODISING A SHEET OF ALUMINIUM OR ALUMINIUM ALLOY USING A PHOSPHORIC ACID AS ELECTROLYTE (II) COATING THE SHEET WITH A PHOTOPOLYMERISABLE RESIN AND (III) OPTIONALLY COLOURING THE RESIN COATING.

Fine dispersion aluminum base bearing and method for making same

Abstract: 1,222,262. Bearings. CLEVITE CORP. 4 June, 1968 [12 Feb., 1968], No. 26639/68. Heading F2A. [Also in Division C7] A bearing comprises a layer of compacted pre-alloyed particles each having 55-95% by wt. aluminium and having distributed therethrough 5-45% by wt. of bearing phase material consisting of a mixture comprising 0.25% by wt. Pb, 0-25% Sn, 0-25% Cd, 0-25% Bi, 0-25% Sb, bonded to a steel backing layer by a bonding layer of compacted powder particles consisting either of pure aluminium or of an aluminium alloy and one or more non-bearing phase materials or of one or more non-bearing phase materials and aluminium. The bonding and/or bearing layer may also contain Si, Cu, Mn, Mg, Ni, Fe, Zn, Cr, Zr, Ti. The bearing is made by roll cladding a strip of bonding layer and bearing layer on to a backing layer. A sacrificial layer may be provided on the bearing layer to protect it during rolling. The sacrificial layer comprises an aluminium alloy which may contain one or more of the elements Si, Cu, Mn, Mg, Ni, Fe, Zn, Cr, Zr, Ti, Cd, Sb, Bi, Pb, Sn. After roll cladding the bonding layer on to the backing layer, the sacrificial layer is removed and the strip blanked and formed to the required bearing shape.

On the lifetime of vacancies in thin foils made from quenched specimens

Abstract: In order to calculate the rate of escape of vacancies at the surfaces of a thin foil specimen prepared from a quenched sample of an aluminium-5 wt. % magnesium alloy, Eikum and Thomas, in a recent paper, used a mobility energy deduced from a plot of rate of loop growth versus reciprocal temperature. It is shown that diffusion parameters derived from such Arrhenius plots are not usually meaningful unless extreme precautions are taken. It is reconfirmed that the observed growth of prismatic loops in the aluminium alloy is only possible if the foil surfaces are sealed by an oxide film. Other evidence for the oxide film effect is reviewed and discussed.

Method of producing road safety devices of heat treated aluminium alloy

Abstract: 1,217,765. Heat-treating aluminium alloys. CEGEDUR GP. May 17, 1968 [May 19, 1967], No.23679/68. Heading C7A. Road safety rails and their supporting posts are produced by forming, solution treating, quenching and artificially ageing at 100‹C. to 200‹C. an alloy consisting of, in percentage by weight Quenching may be effected in water, oil, air, or by water spray, while if forming is carried out by press drawing solution treatment is effected simultaneously and quenching may follow immediately.

Effect of Shot Peening on Stress-Corrosion Properties and Stress Distribution in Aluminium Alloy D.T.D. 5054

Abstract: Stress-corrosion data have been obtained from shot-peened specimens cut in the short transverse direction from an aluminium-alloy extrusion to specification D.T.D. 5054. The specimens were prepared for test in three different ways, to obtain three different residual macro stress systems, typical of the conditions in which the alloy is used in service; it has been shown that, after shot peening, the stresscorrosion properties of each of the three groups of specimens have been improved to a marked extent. X-ray diffraction studies on the specimens have shown that for the particular intensity of peening employed, the resulting highly stressed compressive layer on the surface is of the order 0·006 in. thick and that all evidence of the pre-peening residual stress on the specimen surface has been obliterated. The residual stress nleasurements show that the balancing tensile stresses are distributed through the remainder of the section rather than concentrated in peak form immediately below the induced ...

A method of improving the adhesion of substances to metal surfaces

Abstract: A metal surface is treated to improve adhesion to the surface of substances such as lacquers, printing inks, adhesives or high molecular weight substances used for coatings or linings, by the application of a high frequency say 25 to 75 kc/s, high tension alternating field at a voltage exceeding 50,000 volts. The metal surfaces may be a sheet, strip or foil of aluminium or aluminium alloy semifinished stock of processing length e.g. cut sheets, tubes. Coating materials mentioned are polyolefins e.g. polyethylene. The treated metal surface may be coated with metals by spraying, vaporizing, or plating. The alternating field may be provided by fixed electrodes, or electrodes in the form of rotating barrels, optionally cooled, with the metal surface forming the counter electrode which is continuously fed tangentially past the barrel electrode. The metal surface may be consecutively exposed to several alternating fields, and both sides of the metal may be treated by one or more electrodes simultaneously. The treatment may be combined with known treatments such as an adhesion-assisting lacquer (priming) process, anodic oxidation, phosphatisation, and may follow a degreasing treatment. In the Examples, (2) annealed aluminium foil after electrical treatment is coated with a high pressure polyethylene, by extrusion; (8) electrically treated aluminium foil is faced with polypropylene foil with the aid of a polyesterpolyisocyanate adhesive; (10) aluminium foil is treated electrically to accept printing, lacquering or facings without further treatment.

Process for preparing aluminium base alloy

Abstract: An aluminium alloy containing Si 0.6-0.9%, Mg 0.4-0.6%, Al the remainder is cast, homogenized to provide a uniform distribution of the Si and Mg in the alloy, extruded at more than 950 DEG F. and then cooled to 350 DEG F. or below in not more than 4 minutes. The alloy may be homogenized at 970-1100 DEG F. for 4-20 hours; if necessary it is heated to 970 DEG F. or above for at least 2 minutes immediately prior to extrusion. After extrusion the section is cooled by air blast or water spray and may then be aged at 200-410 DEG F. for 15 minutes - 9 hours.

Improvements in or relating to the coating of metals

Abstract: 1,136,394. Flame spraying. BRITISH ALUMINIUM CO. Ltd. July 7, 1966 [July 9, 1965], No. 29225/ 65. Heading C7F. [Also in Division B2] A metal section is treated by shaping the section at an elevated temperature with a metal-shaping tool and spraying the section with a coating material after the section has been shaped before it cools below 200‹ C. without intermediate cleaning of the surface of the section. The coating material may be a metal e.g. aluminium or an alloy thereof, alumina or plastics and "cermet" materials, and may be applied by a spray gun or by splutter spraying. Metal sections shaped by extrusion or rolling and consisting of aluminium or an alloy thereof may be coated e.g. an extruded section composed of an aluminium alloy of composition 0-0A10% copper, 0A4-1A4% magnesium, 0A6-1A3% silicon, 0-0A5% iron, 0A4-1A0% manganese, 0-0A1% zinc, 0-0A2% titanium, 0-0A3% chromium and balance aluminium is splutter sprayed as it leaves the extrusion die at 500‹C. with 99A5% purity aluminium, or wire of the alloy is sprayed on to the extruded section of the alloy. In an embodiment, a sheet of the alloy is extruded with longitudinal channels of trapezoidal cross-section. In the Figure the sheet is formed along one longitudinal edge with an upward opening channel 1 the outer wall 2 of which is intended to engage under a longitudinally extending lip 3 formed on the opposed longitudinal edge so that the sheets may be interlocked to form a landing surface for aircraft. The surface of the sheet between adjacent upwardly opening channels indicated at 4 is coated with 99A5% purity aluminium as the extruded sheet leaves the die at 500‹ C. The coatings may be selected for resistance to wear, corrosion or for decorative effect.

Fretting Corrosion Products of Aluminium Alloys

Abstract: An examination of a black powder produced by the fretting of aluminium alloy surfaces in a ship's hold has been carried out.The fire risk associated with the accumulation of this type of material in confined spaces has been considered.

Improvements in or relating to insulator suspension caps

Abstract: The Specification describes an aluminium alloy for making a bell-shaped cap 24 of an electric time insulator. A suitable aluminium alloy contains by weight 7% silicon, 0.25-0.4% magnesium and 0.1% copper. The alloy is subjected to standard aluminium heat treatment which includes solution heating and artificial ageing.

Improvements in or relating to corrosion preventing compositions

Abstract: Corrosion-preventing coating compositions comprise a dispersive medium and a particulate material coated with lead, a lead alloy, tin or a tin alloy. The particulate material may be another metal such as aluminium, an aluminium alloy, magnesium, a magnesium alloy, or zinc, an organic elastomer such as polyvinyl chloride, polyethylene, polypropylene, or nylon, or an inorganic material such as mica, asbestos, vermiculite or micaceous iron ore. The ratio of coating agent to particulate material may be 2-15% by weight. Coating may be effected by milling. A suitable dispersing medium is an oil modified heat hardening phenolic resin. In the examples, the dispersing medium is an unspecified resin base. Composition 3 discloses lead coated polythene, polypropylene and polyvinyl chloride powders. The coated particles per se are claimed when coated by mechanical means.ALSO:A corrosion-preventing coating composition and lubricant for wire, paricularly steel wire, comprises a dispersive medium containing a particulate material coated with lead, a lead alloy, tin or a tin alloy. The particulate material may be another metal such as aluminium, an aluminium alloy, magnesium, a magnesium alloy, or zinc, an organic elastomer such as polyvinyl chloride, polyethylene, polypropylene or nylon, or an inorganic material such as mica, asbestos, vermiculite or micaceous iron ore in a ratio of coating agent to particulate material of 2-15% by weight. Coating may be effected by milling. Suitable dispersive media include lanolin, or a synthetic resin plus (a) benzoyl peroxide or (b) a drying or semi-drying oil such as linseed oil, either of which promote polymerization of the resin. In examples the compositions contain also white spirit and micro-crystalline wax, and the resin is unspecified. The coated particles per se are claimed when coated by mechanical means.ALSO:Corrosion-resistant particles comprise inorganic or organic material mechanically coated overall with lead, a lead alloy, tin or a tin alloy. The particulate substrate may be aluminium, an alloy thereof, magnesium, an alloy thereof, zinc, polyvinyl chloride, polyeltrylene, polypropyltne, nylon, mica, asbestos, vermiculite, or micaceous iron ore, and the coating may amount to 2-15% by weight thereof. Coating is effected by milling.ALSO:Metal wire, particularly steel wire, is given a corrosion-resistant coating of a lacquer comprising a dispersive medium and a particulate material coated with lead, a lead alloy, tin, or a tin alloy. The particulate material may be another metal viz. aluminium, an aluminium alloy, magnesium, a magnesium alloy, or zinc, an organic elastomer such as polyvinyl chloride, polyethylene, polypropylene, or nylon, or an inorganic material such as mica, asbestos, vermiculite, or micaceous iron ore. Dispersive media specified are lanolin, or a synthetic resin e.g. an oil-modified heat-hardening phenolic resin plus (a) benzoyl peroxide or (b) a drying or semi-drying oil such as linseed oil, either of which promote resin polymerisation. The composition may be brushed or sprayed on to the metal substrate.

Improvements in or relating to photolithographic printing plates

Abstract: 1,113,508. Etching. W. H. HOWSON Ltd. 8 Dec., 1966 [9 Dec., 1965], No. 52215/65. Heading B6J. [Also in Division G2] Photolithographic plates are produced by (i) coating an anodized aluminium or aluminium alloy support with a light-sensitive material, (ii) image-wise exposing and developing the, coating, (iii) etching away the exposed anodized surface to reveal the aluminium, (iv) depositing a layer of ink-accepting metal (e.g. copper) on the aluminium, (v) optionally coating the copper with a greasy ink or protective lacquer and (vi) removing the resist from the support. Etching agents which may be used are alkali metal hydroxides, sodium zincate, ferric chloride and hydrochloric acid, copper borofluoride, hydrofluorosilicic acid, sodium dichromate and phosphoric acid, and hydrofluoric acid. The preferred etching solution is hydrofluoric acid in monoethylene glycol.

A process for producing trialkylaluminium and, optionally, isobutene

Abstract: 1,132,377. Trialkyl aluminium. SUMITOMO CHEMICAL CO. Ltd. 10 June, 1966, No. 26074/66. Heading C2J. [Also in Division C5] A trialkyl aluminium in which the alkyl group is principally 2-ethylhexyl, is produced in a three-step process. In the first step a butanebutene mixture (generally a C 4 fraction from petroleum which preferably contains at least 10% of 1-butene and isobutene and less than 1% of butadiene) is heated in the presence of an alkyl aluminium compound (which is preferably a trialkyl aluminium or dialkyl-aluminium hydride where the alkyl group is isobutyl, nbutyl or octyl), the molar ratio of 1-butene to alkyl aluminium being between 5 and 50 to 1, the temperature 130-220‹ C. and the pressure from 5-100 Kg/cm. 2 gauge until the 1-butene has dimerized, mainly to 2-ethylhexene. The octenes formed are separated from the unreacted hydrocarbon mixture. In the second step, the octene mixture is reacted with an isobutyl aluminium compound (preferably triisobutyl aluminium, diisobutyl aluminium hydride or a mixture thereof) at a temperature of 80-170‹ C. under reflux in an inert hydrocarbon solvent which preferably has a boiling-point below 130‹ C. (e.g. octane, heptane, hexane, pentane, cyclohexane, benzene or toluene) to form the trialkyl aluminium, the alkyl groups of which are principally 2-ethyl hexyl. In the third and optional step, the butane-butene mixture separated in step one is reacted with di-isobutyl aluminium hydride to convert the isobutene in the mixture to tri-isobutyl aluminium, which is separated from the butenebutane hydrocarbon mixture and heated to produce isobutene and di-isobutyl aluminium hydride. The isobutyl aluminium compound used in the second step may be the one produced in the third step and the di-isobutyl aluminium hydride used in the third step may be prepared by reaction of the tri-isobutyl aluminium produced in the third step with aluminium or an aluminium alloy.