Showing papers on "Aluminium alloy published in 1970"

Process for fluxing and brazing parts made of aluminium or aluminium alloy

Abstract: The process is characterized in that one proceeds to prepare a fluxing compound, in that a thin coat of this compound is deposited on at least those of portions of parts requiring to be assembled, then that after partly melting the compound the parts are heated up to brazing temperature.

The effect of plastic deformation at −196°C on pre-precipitation in a quenched Al-6.8 at. % Zn alloy

Abstract: The effect of plastic deformation at -196°C on the growth of G.P. zones in an aluminium alloy containing 6.8 at. % zinc was investigated by means of electrical resistivity and x-ray small-angle scattering. The enhancement of the growth process in the early stages of ageing by the plastic deformation was verified. Analysis of x-ray small-angle scattering profiles shows that G.P. zones of the deformed specimen do not grow as large as in undeformed specimens. Examination of the variation of x-ray intensities suggests that deformation decreases the solute concentration in the zones, increases the solute concentration in the matrix, and reduces the number of zones.

Residual Stresses Induced By Hole Cold Expansion

Abstract: This paper describes an X-ray diffraction technique for measuring residual stresses. The results of measurements at locations in the vicinity of plain and cold expanded holes in an aluminium alloy are presented. Residual stresses are shown to vary significantly in all three dimensions and two dimensional analyses commonly used for residual stress determination are shown to be inadequate. The results of a fatigue test programme are also presented in which simple aluminium alloy specimens containing plain and cold expanded holes were subjected to constant amplitude fatigue loading. The results show that cracks from plain holes continuously increase in growth rate to failure whilst cracks from cold expanded holes decrease in growth rate and frequently arrest. The arrested crack lengths are different on either face of the cold expanded specimens and this is equated to the different residual stress fields present. Fatigue crack growth rates predicted using a Green's function technique are compared with those measured experimentally.

Improving mechanical properties of aluminium alloy through addition of coconut shell-ash

Abstract: This paper investigates the microstructure and mechanical properties of aluminum alloy (Al-Si-Fe) reinforced with coconut shell-ash particulate. The aluminium (Al-Si-Fe) alloy composite was produced by a double-stir casting process at a speed of 700 rpm for 10 and 5 minutes at first and second stirring respectively. The samples produced from addition of 0-15 wt% coconut shellash particles (CSAp) were prepared and subjected to microstructural and mechanical properties testing. The results of the microstructural analysis of the composite reveal a fairly uniform distribution of the coconut shell-ash particles in the matrix with increase in volume fraction of CSAp. The mechanical property test results revealed that, hardness of the developed composite increased with increasing percentage weight of CSAp. Also the tensile and yield strength at 0.2% offset values of Al-Si-Fe/CSAp composite increased with percentage increase in CSAp up to 9% addition above which a little decrease in both tensile and yield strength was observed. Keywords: Matrix, coconut shell, mechanical properties, stir- casting, particulate, reinforcements

Chemical Etching of Aluminium in Caustic Soda Based Solutions

Abstract: SummaryThe paper summarises the reactions occurring when aluminium is etched in caustic soda solutions and details the effect of the addition of different anions and cations upon the basic kinetics of etching and upon the appearance of the etched surface. It also details the effect of temperature concentration and the addition of various sequestering agents on the basic reaction with aluminium alloys. The work described also takes into account the effect of the aluminium alloy and the control of etch processes in the factory and their effect upon subsequent metal finishes such as anodizing.

Plastics/metal laminated textile thread stretching - roller

Abstract: Plastics/metal laminated textile thread stretching roller. GG-. Has an annular core made of aluminium, aluminium alloy, copper, brass or steel onto which is bonded an expendable, extruded plastics sleeve. The i. dia of the core is selected such that it is fitted with a press or interference fit on the outer race of a ball bearing and the resultant tensile stress in the core is disposed well below the elastic stress limit of the metal.

Perforated temp stable substrates with very smooth - surfaces

Abstract: A foil of aluminium or aluminium alloy is perforated by masked etching, followed by anodic polishing and rounding of the sharp edges. After hard anodizing by the Eloxal process the foil is sealed. A printed circuit is then produced by depositing a conductive material by evaporation, followed by anodizing.

Machinable aluminium alloy containing lead

Abstract: Lead is added to molten aluminium after the latter leaves the casting furnace and before it enters the ingot mould. Specif. one or more lead wires are introduced into the casting runner. The lead is a granulate.

Process for Forming Surface Diffusion Alloys on Refractory Metal Members

Abstract: 1,186,924. Coating with metals. OFFICE NATIONAL D'ETUDES ETDE RECHERCHES AEROSPATIALES. June 23, .1967 [June 24, 1966], No. 29230/ 67. Heading C7F. Articles of rust-resistant or refractory steels, or of nickel or cobalt alloys, have surface diffusion alloys containing chromium and aluminium, and if desired silicon, formed on them by heating them with an ultrafine powder containing these materials in an alloy and having a mean grain size equal to one micron or less, with an oxide which acts as a chemically inert diluting agent and with a halogen, halogenide, hypohalogenite or a mixture thereof. Heating is carried out in a container which is closed but is not gastight and which is surrounded during heating by a hydrogenated atmosphere which may be of electrolytic hydrogen, of hydrogen and argon or of cracked ammonia. After heating the container may be cooled in a similar atmosphere, preferably by spraying with water. The ultrafine powder of chromium and aluminium alloy is preferably made in situ from chromium and aluminium powders which are heated together in a "blank" operation. Alumina may be used as the diluting agent and ammonium chloride or bromide (advantageously with some aluminium fluoride) is included in the mixture. Both chromium and aluminium may be replenished by adding aluminium powder on each occasion between treatments and some chromium from time to time. Heating is at from 750‹C. to 1200‹C., for not more than 20 hours. Prior to treatment according to the invention, the articles may be given a preliminary sheathing by tantalum diffusion, by heating with tantalum powder, alumina and ammonium chloride, or a preliminary sheathing by chromium diffusion. Nickel alloy articles, for example, may be heated with chromium, nickel, alumina and ammonium chloride, replenished with chromium and ammonium chloride or bromide.

Methods of Joining Metal Members by Brazing

Abstract: 1,193,467. Brazing. MARSTON RADIATORS Ltd. 8 Aug., 1968 [15 Aug., 1967], No. 37409/67. Heading B3R. In joining two metal members in which both are of steel or one is of steel and the other of aluminium or an alloy thereof the members are brazed together with an aluminium-silicon brazing alloy comprising 4-13% silicon preclad on the or each steel member. The silicon in the alloy may be preferably 11A7% and brazing may be effected by salt bath, furnace, electrical induction, torch or vacuum or fluxless brazing, the latter in a gaseous atmosphere. In an example an automobile radiator is constructed from core tubes 1, fins 4, the tubes and fins forming a sub-assembly, header tanks 2, 3 and side plates 5, the side plate 5 and header tanks 2, 3 being of steel sheet clad on both surfaces with the eutectic aluminium 11A7% silicon alloy having a melting point of 577‹ C. and the fins 4 are formed of aluminium or aluminium alloy. The parts are held assembled in a jig and the assembly is passed into a brazing furnace to braze the portions 6 of the side plates 5 to the header tanks and the portions 7 of the side plates to the ends of the fins 4. All the members of a radiator may be formed of clad steel and oil coolers, air heating equipment for aircraft, evaporator panels and condensers may be constructed.

Electric iron sole plate

Abstract: 1,203,145. Electric irons. W. B. ROBINSON. 2 May, 1969 [7 May, 1968], No. 21504/ 68. Addition to 1,077,741. Heading D1A. An electric iron sole plate comprises a metal casing 14 with, on one side, a flat ironing surface 15 and secured on the other side a metal core plate 18 which is separated therefrom by a small air gap 21 over the area 20 below the heating elements and which is of lower thermal conductivity than the casing. As shown, plate 18 of cast iron or mild steel is held in recess 16 in casing 14 which is of aluminium or aluminium alloy by screws screwed into bosses 17 or by riveting, bolting or welding. In a steam iron plate 18 will be of stainless steel.

Improvements in or relating to Polytetrafluoroethylene Coatings on Metallic Bases

Abstract: 1,180,704 Cooking vessels NATIONAL PRESTO INDUSTRIES Inc 26 July, 1968, No 35895/68 Heading A4A [Also in Division B2] A cooking vessel comprises a metallic base coated with a first layer comprising a mixture of polytetrafluoroethylene, finely divided non-spherical particles of metal and finely divided particles of a metal oxide, a metal carbide, or mixtures thereof, and then a second layer consisting essentially of PTFE The non-spherical particles of metal may have an average size of about 20-12 microns The first laver may he formed by first baking on to the metallic base, the mixture, and then baking on to the first layer the PTFE to form the second layer The base which may be of, for example, aluminium, aluminium alloy, iron, steel, copper, brass, may be first cleaned by blasting with grit, sand or oxide, or etched The non-spherical particles may be of aluminium, iron, steel, copper, brass, chromium or nickel The oxide or carbide may be of aluminium, titanium, zirconium, silicon, chromium and nickel The first layer may be formed by baking on the metallic base a mixture comprising 50-60 volumes of aluminium oxide powder, 50- 40 volumes of aluminium powder, the two together making up 100 volumes, and 100 volumes of polytetrafluoroethylene emulsion that contains 50 per cent by weight of solid polytetrafluoroethylene resin The first layer may be about 1 mil and the second layer about 04 mil in thickness The coating provides a surface portion which is characterized by a high degree of abrasion resistance, scratch resistance and resistance to sticking thereto of foods in contact therewith during cooking

Aluminium alloy with copper, magnesium and - zinc

Abstract: Resistance to stress corrosion cracking is effected without noticeable reduction in strength or weight penalties by heating Al alloy contg. Cu, Mg and Zn to 460-477 degrees C for time sufficient to allow constituents to enter into solid soln., quenching with water and ageing by (a) first heating to 96-107 degrees C for 6-10 hrs., and then (b) to 149-193 degrees C for 2-48 hrs. Pref. alloy is cooled to room temp. before last heating step. Pref. (b) ageing step takes place by heating to 157-179 degrees C for 4-18 hrs.

Laminar-granular or flaky-pulverous spat- - cooled aluminium alloy melts

Abstract: Metal leads are centrifuged from rotating crucibles, which have suitable apertures, or from siphons on to a cooling surface at an angle 30 degrees. Spec., the surface is a vibrated to ease the removal of the solidified particles.

Improvements in or relating to Bearing Bushes and Blanks therefor and the Manufacture thereof.

Abstract: 1,181,472 Bearings C WATSON 19 July, 1968 [3 May, 1968], No 21107/68 Heading F2A A cylindrical bearing bush comprises an inner liner of phosphor-bronze and an outer sleeve of a material other than phosphorbronze, and is made either by shrinking the sleeve on to the liner or expanding the liner into the sleeve by means of heat treatment The outer sleeve may be of cast iron, steel, aluminium, aluminium alloy, lead, plastics or filled asbestos

Porous bearing of powdered metal synthetic - ally bonded

Abstract: Porous metal powder, aluminium alloy with up to 30% lead, 0.5 to 15% zinc and/or 0.5 to 5% silicon, is bonded with a synthetic plastic, to form the bearing layer. The grain size of the metal should be between 50 and 1000 microns especially between 200 to 400 microns. The synthetic bond should be from the group polyamine, polyethylene, polypropylene PVC or tetrafluoroethylene.

An experimental study of the stress histories at stress concentrations in aluminium alloy specimens under variable amplitude loading sequences

Abstract: In this paper an investigation is described of residual stresses associated with plastic deformation at a stress concentration in an aluminium alloy specimen. Local stresses were determined, by an indirect method, under a variety of sequences of loads which included peaks high enough to cause local yielding. Sequences at bath zero and a positive mean stress were applied. Conclusions are drawn with respect to the effects of residual stresses generated by such yielding on the accuracy of fatigue life prediction and on the design of loading sequences to be applied in the laboratory as a representation of service loading actions.

Nickel-Chromium-Cobalt-Aluminium Alloy

Abstract: 1,193,774. Nickel base alloys. ROLLSROYCE Ltd. April 2, 1969 [April 5, 1968], No. 16488/68. Heading C7A. A nickel base alloy, especially suitable for blades or vanes in gas turbine engines, comprises:- the balance, apart from impurities and residual deoxidizers, being Ni, and is so proportioned that the "F" factor Cr + Co/3 = 17A5-20% and Al + Ti +Nb + Ta is in the range 12A25 - 0A15F to 13A275- 0A15F.

Process for the Surface Preparation of Aluminium and/or Aluminium Alloy Parts which are to be Resistance Welded.

Abstract: 1,199,518. Welding by pressure. CEGEDUR G.P. 15 Nov., 1968 [17 Nov., 1967], No. 54345/68. Heading B3R. In resistance welding aluminium and/or aluminium alloy parts a composition is applied to the faces to be engaged by the electrodes, the composition comprising a mixture of hydrocarbons containing at least 60% of saturated mono or polycyclic hydrocarbons of formula C n H 2n (naphthenes or naphthenic petroleum products) with the remainder paraffinic or saturated acyclic hydrocarbons of formula C n H 2n+2 . The resistance welding may be both spot and roller welding and the composition may include viscosity or oiliness agents or anti-corrosion additives. The composition may be applied immediately before welding or even a number of months before welding by a brush, gum, roller, cloth or machine. In an example aluminium alloy sheet containing 2.6% Cu, 0.4% Mg for the motor vehicle bodies are coated on both sides with a mineral oil containing 62% napthenes and 38% paraffinic hydrocarbons and are spot-welded. In another example, both faces of the sheet are roller coated four months before spot-welding with an oil containing 70% naphthenes and 30% paraffinic hydrocarbons and in another example, sheets of aluminium alloy containing 3.2% Mi and 0.2% Mn are coated by a gun only on the outer faces with an oil containing 65% napthenes, 34.5% paraffinic hydrocarbons and 0.5% bacon oil and are spot-welded.