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Sample records for aa5052 aluminium alloy

  1. The growing rate and the type of corrosion products of aluminium alloy AA 5052 in deionized water at temperature up to 3000C

    The process of corrosion concerning the aluminum alloy AA5052 in deionized water at temperatures of 400C, 800C, 900C, 1400C, 2000C and 2800C is studied. The following methods are used: periodic weighting of the test samples; analysis by neutronic activation of the corrosion products dissolved in water; thermogravimetric and thermodiferential analysis; analysis through X-ray diffraction and from metalografic observations of the crystals produced in the corrosion process; an optical microscope using polarized and normal light and a scanning electronic microscope. The activation energies are calculated for the corrosion film formation, and for the dissolution of the corrosion products in the deionized water. (ARHC)

  2. Effect of hot and cold deformation on the recrystallization texture of continuous cast AA 5052 aluminum alloy

    The effect of different relative amounts of hot and cold deformation on the recrystallization texture of a continuous cast AA 5052 aluminum alloy was investigated by X-ray diffraction. The results show that hot deformation promotes the cube and Goss components at the expense of the r-cube and remainder components. The formation of the R component does not appear to be affected by hot and cold deformation

  3. Effect of hot and cold deformation on the recrystallization texture of continuous cast AA 5052 aluminum alloy

    Liu, W.C. [Department of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506 (United States)]. E-mail: wcliu@engr.uky.edu; Man, C.-S. [Department of Mathematics, University of Kentucky, 715 Patterson Office Tower, Lexington, KY 40506 (United States); Raabe, D. [Max-Planck-Institut fuer Eisenforschung, Microstructure Physics, Max-Planck-Str. 1, 40237, Duesseldorf (Germany); Morris, J.G. [Department of Chemical and Materials Engineering, University of Kentucky, 177 Anderson Hall, Lexington, KY 40506 (United States)

    2005-12-15

    The effect of different relative amounts of hot and cold deformation on the recrystallization texture of a continuous cast AA 5052 aluminum alloy was investigated by X-ray diffraction. The results show that hot deformation promotes the cube and Goss components at the expense of the r-cube and remainder components. The formation of the R component does not appear to be affected by hot and cold deformation.

  4. Effect of temperature on the anodizing process of aluminum alloy AA 5052

    Theohari, S.; Kontogeorgou, Ch.

    2013-11-01

    The effect of temperature (10-40 °C) during the anodizing process of AA 5052 for 40 min in 175 g/L sulfuric acid solution at constant voltage (15 V) was studied in comparison with pure aluminum. The incorporated magnesium species in the barrier layer result in the further increase of the minimum current density passed during anodizing, as the temperature increases, by about 42% up to 30 °C and then by 12% up to 40 °C. Then during the anodizing process for 40 min a blocking effect on oxide film growth was gradually observed as the temperature increased until 30 °C. The results of EDAX analysis on thick films reveal that the mean amount of the magnesium species inside the film is about 50-70% less than that in the bulk alloy, while it is higher at certain locations adjacent to the film surface at 30 °C. The increase of anodizing temperature does not influence the porosity of thin films (formed for short times) on pure aluminum, while it reduces it on the alloy. At 40 °C the above mentioned blocking effects disappear. It means that the presence of magnesium species causes an impediment to the effect of temperature on iss, on the film thickness and on the porosity of thin films, only under conditions where film growth takes place without significant loss of the anodizing charge to side reactions.

  5. Recrystallization microstructures and textures in AA 5052 continuous cast and direct chill cast aluminum alloy

    Commercially produced hot bands of AA 5052 continuous cast (CC) and direct chill (DC) cast aluminum alloys were cold rolled to (thickness) reductions of 70%, 80%, and 90% followed by annealing at different conditions. The recrystallization kinetics are found equivalent for both the CC and DC materials. Recrystallization microstructures are different between the CC and DC materials. Evolution of recrystallization texture in the CC and DC materials were investigated by using three-dimensional orientation distribution functions (ODFs) that were determined by X-ray diffraction. The recrystallization texture was correlated with cold rolling reduction (prior to annealing), annealing temperature, and annealing time. Results showed that the R {124} and cube {001} are dominant recrystallization texture components in both CC and DC materials. During annealing, the intensity and volume fraction of the cube component strongly depend on the prior cold rolling history. In contrast, the intensity and volume fraction of the R component remains almost constant regardless of the different cold rolling reductions prior to annealing. After complete recrystallization, the intensity and volume fraction of both R and cube components appear to be independent of the annealing temperature and annealing time

  6. Effect of tool rotational speed on force generation, microstructure and mechanical properties of friction stir welded Al–Mg–Cr–Mn (AA 5052-O) alloy

    Highlights: • 3 mm thick AA 5052-O alloy plates were successfully joined by FSW process. • The joint was produced at 1000 rpm yielded a maximum tensile strength of 132 MPa. • The dissolution of β-Mg2Al3 intermetallic phases of FSWed joints were reported. • Different axial forces acted on welding tool during welding were investigated. - Abstract: Friction stir welding (FSW) between 3 mm thick AA 5052-O aluminum alloy plates was investigated in the present study. Different welded specimens were produced by employing a constant tool traverse speed of 120 mm/min and by varying rotating speeds from 800 to 3000 rpm. The welded joints were characterized by its appearances, microstructural and mechanical properties at room temperature. The measurement of different forces acted on the tool during the FSW of AA 5052-O plates provided a significant insight to determine the quality of the welded joints. From the appearances of the welded joints it was evident that, except the tool rotational speed of 3000 rpm all other rotational speeds produced sound welded joints with smooth surface. The joint produced at 1000 rpm yielded a maximum tensile strength of 132 MPa which was 74% of the base material strength. Field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS) analyses on the stir zone suggested that, β-Mg2Al3 intermetallic phases of the base material were mechanically fractured, smeared and mixed to different geometries due to tool stirring. The dissolution and redistribution of β-Mg2Al3 second phase particles in the stir zone had a considerable effect on the reduction of the tensile strength of the welded joints. The reduction in hardness at the nugget zone (NZ) of the welded joints under different tool rotational speeds could be attributed to the dislocation of Mg-rich phases and segregation of Mg solute atoms at grain boundaries, which drew solute Mg atoms away from the α-aluminum matrix

  7. The Effect of Fe Content on Recrystallization Texture Evolution, Microstructures, and Earing of Cold Rolled Continuous Cast AA5052 Alloy Sheets

    Wen, Xiyu; Wen, Wei; Zhang, Yuanbin; Xu, Bin; Zeng, Qiang; Liu, Yansheng; Tong, Lirong; Zhai, Tongguang; Li, Zhong

    2016-04-01

    Continuous cast AA5052 Al alloys, containing iron contents of 0.120 and 0.466 wt pct, respectively, were cold rolled and annealed at temperatures ranging from 505 K to 755 K (232 °C to 482 °C). The recrystallization textures in the two alloys were analyzed using X-ray diffraction and electron back scatter diffraction, respectively. It was found that higher Fe content promoted the formation of deformation textures and retarded the formation of cube texture in the two alloys. Most cube-oriented grains formed in both these alloys were associated with coarse particles, whereas the P—{011}, R—{123}, and Goss or randomly oriented grains were often related to particle stringers consisted of fine particles along the rolling direction. It was also found that the volume fraction of each texture component was a Johnson-Mehl-Avrami-Kolmogorov-type function of annealing temperature in the two alloys. The texture evolution rate with the annealing temperature was calculated from this function and used to determine the onset temperature of each recrystallization texture component.

  8. A crystallographic texture perspective formability investigation of aluminium 5052 alloy sheets at various annealing temperatures

    Narayanasamy, R. [Department of Production Engineering, National Institute of Technology, Tiruchirappalli - 620015, Tamilnadu (India); Ravindran, R. [Department of Mechanical Engineering, VLB Janakiammal College of Engineering and Technology, Coimbatore - 641042, Tamilnadu (India)], E-mail: mceravindran@yahoo.co.in; Manonmani, K. [Department of Mechanical Engineering, Government College of Technology, Coimbatore - 641013, Tamilnadu (India)], E-mail: manokmani@yahoo.co.in; Satheesh, J. [Department of Production Engineering, National Institute of Technology, Tiruchirappalli - 620015, Tamilnadu (India)

    2009-05-15

    Formability, an important mechanical property of the sheet metal is strongly reliant on the crystallographic texture. Consequently deep drawability is also influenced. This paper deals with the perspective of crystallographic texture and its relevance with the formability of AA 5052 aluminium alloy sheet of 2 mm thickness annealed at four different temperatures namely 200 deg. C, 250 deg. C, 300 deg. C and 350 deg. C. Forming limit diagrams determined and plotted experimentally, their crystallographic textures obtained and their ODF plots prepared by X-ray diffraction were analyzed. The Forming limit diagrams (FLDs) of AA 5052 sheets annealed under different temperatures were examined with respect to the crystallographic texture point of view. The FLDs and crystallographic textures were then correlated with normal anisotropy of the sheet metal. It was found that the formability of aluminium alloy AA 5052 annealed at 350 deg. C possessed good formability, optimal texture and high normal anisotropy value.

  9. Resistance Spot Welding of AA5052 Sheet Metal of Dissimilar Thickness

    Mat Din, N. A.; Zuhailawati, H.; Anasyida, A. S.

    2016-02-01

    Resistance spot welding of dissimilar thickness of AA5052 aluminum alloy was performed in order to investigate the effect of metal thickness on the weldment strength. Resistance spot welding was done using a spot welder machine available in Coraza Systems Sdn Bhd using a hemispherical of chromium copper electrode tip with radius of 6.00 mm under 14 kA of current and 0.02 bar of pressure for all thickness combinations. Lap joint configuration was produced between 2.0 mm thick sheet and 1.2 - 3.2 mm thick sheet, respectively. Microstructure of joint showed asymmetrical nugget shape that was larger on the thicker side indicating larger molten metal volume. Joint 2.0 mm x 3.2 mm sheets has the lowest hardness in both transverse direction and through thickness direction because less heat left in the weld nugget. The microstructure shows that this joint has coarse grains of HAZ. As thickness of sheet metal increased, the failure load of the joints increased. However, there was no linear correlation established between joint strength and metal thickness due to different shape of fusion zone in dissimilar thickness sheet metal.

  10. Soldering of aluminium alloys

    A literature survey about soldering in general and aluminium alloys soldering in particular is presented. The existing methods of soldering aluminium alloys are described. These include soldering with flux, soldering after preliminary plating, vacuum brazipressure and temperature (NTP), sample age calculation based on 14C half life of 5570 and 5730 years, age correction for NTP, dendrochronological corrections and the relative radiocarbon concentration. All results are given with one standard deviation. Input data test (Chauvenet's criterion), gas purity test, standard deviation test and test of the data processor are also included in the program. (author)

  11. Texture evolution of AA5052 during monotonic and reversed hot deformation and subsequent recrystallization

    Zhu, Q.; Wynne, B.P.; Beynon, J.H.; Sellars, C.M. [Univ. of Sheffield, Inst. for Microstructural and Mechanical Process Engineering, Sheffield (United Kingdom)

    2002-07-01

    During industrial thermomechanical processing such as forging, rolling and extrusion, local regions within the stock undergo different strain paths. A significant effect of a change in strain path on microstructural evolution and subsequent recrystallisation behaviour has been observed previously for several texture free Al-Mg alloys under conditions of hot deformation in tension/compression. The mechanism of the effect is related to the evolution of geometrically necessary dislocations including the evolution of microbands, which are heterogeneously distributed in deforming materials and depend upon the orientation of grains. This work is currently being extended to texture evolution during continuous and reversed deformation. The combined effects of strain path on dislocation substructures and on deformation texture determine the subsequent recrystallisation behaviour and recrystallisation texture, which in turn dominate deep drawing properties of sheets. The present paper shows the effect of a change in strain path on the evolution of texture during either simple shear or axisymmetric deformation of AA5052 and during annealing of the deformed materials. The experimental alloy has initial Goss and Cube texture components. The simple shear was carried out in a reversible torsion machine and axisymmetric deformation in a tension/compression-testing machine. Texture was examined both using an X-ray texture goniometer and by electron backscattered diffraction (EBSD) in a scanning electron microscope. The results show that the evolution of texture is different during monotonic and reversed shear deformation. After annealing to partially recrystallise, the difference of orientation distribution becomes more significant than in the specimens deformed in torsion. After annealing for a short time, where no recrystallisation can be found, the texture components are different from the partially recrystallised specimens. (orig.)

  12. High-Temperature Tensile and Tribological Behavior of Hybrid (ZrB2+Al3Zr)/AA5052 In Situ Composite

    Gautam, G.; Kumar, N.; Mohan, A.; Gautam, R. K.; Mohan, S.

    2016-09-01

    During service life, components such as piston, cylinder blocks, brakes, and discs/drums, have to work under high-temperature conditions. In order to have appropriate material for such applications high-temperature studies are important. Hybrid (ZrB2+Al3Zr)/AA5052 in situ composite has been investigated from ambient to 523 K (250 °C) at an interval of 50 deg. (ZrB2+Al3Zr)/AA5052 in situ composite has been fabricated by the direct melt reaction of AA5052 alloy with zirconium and boron salts. Microstructure studies show refinement in the grain size of base alloy on in situ formation of reinforcement particles. Al3Zr particles are observed in rectangular and polyhedron shapes. It is observed from the tensile studies that ultimate tensile strength, yield strength, and percentage elongation decrease with increase in test temperature. Similar kind of behavior is also observed for flow curve properties. The tensile results have also been correlated with fractography. Wear and friction results indicate that the wear rate increases with increase in normal load, whereas coefficient of friction shows decreasing trend. With increasing test temperature, wear rate exhibits a typical phenomenon. After an initial increase, wear rate follows a decreasing trend up to 423 K (150 °C), and finally a rapid increase is observed, whereas coefficient of friction increases continuously with increase in test temperature. The mechanisms responsible for the variation of wear and friction with different temperatures have been discussed in detail with the help of worn surfaces studies under scanning electron microscope (SEM) & 3D-profilometer and debris analysis by XRD.

  13. High-Temperature Tensile and Tribological Behavior of Hybrid (ZrB2+Al3Zr)/AA5052 In Situ Composite

    Gautam, G.; Kumar, N.; Mohan, A.; Gautam, R. K.; Mohan, S.

    2016-07-01

    During service life, components such as piston, cylinder blocks, brakes, and discs/drums, have to work under high-temperature conditions. In order to have appropriate material for such applications high-temperature studies are important. Hybrid (ZrB2+Al3Zr)/AA5052 in situ composite has been investigated from ambient to 523 K (250 °C) at an interval of 50 deg. (ZrB2+Al3Zr)/AA5052 in situ composite has been fabricated by the direct melt reaction of AA5052 alloy with zirconium and boron salts. Microstructure studies show refinement in the grain size of base alloy on in situ formation of reinforcement particles. Al3Zr particles are observed in rectangular and polyhedron shapes. It is observed from the tensile studies that ultimate tensile strength, yield strength, and percentage elongation decrease with increase in test temperature. Similar kind of behavior is also observed for flow curve properties. The tensile results have also been correlated with fractography. Wear and friction results indicate that the wear rate increases with increase in normal load, whereas coefficient of friction shows decreasing trend. With increasing test temperature, wear rate exhibits a typical phenomenon. After an initial increase, wear rate follows a decreasing trend up to 423 K (150 °C), and finally a rapid increase is observed, whereas coefficient of friction increases continuously with increase in test temperature. The mechanisms responsible for the variation of wear and friction with different temperatures have been discussed in detail with the help of worn surfaces studies under scanning electron microscope (SEM) & 3D-profilometer and debris analysis by XRD.

  14. Hydrogen generation from aluminium corrosion in reactor containment spray solutions

    The aluminium corrosion experiments in reactor containment spray solutions, under the conditions expected to prevail during LOCA in BWR and PWR, were performed in order to investigate relationships between temperature, pH and hydrogen production rates. In order to simulate the conditions in a BWR containment realistic ratios between aluminium surface and water volume and between aluminium surface and oxygen volume were used. Three different aluminium alloys were exposed to spray solutions: AA 1050, AA 5052 and AA 6082. The corrosion rates were measured for BWR solutions (deaerated and aerated) with pH 5 and 9 at 50, 100 and 1500C. The pressure was constantly 0.8 MPa. The hydrogen production rate was measured by means of gas chromatography. In deionized BWR water the corrosion rates did not exceed about 0.05 mm/year in all cases, i.e. were practically independent of temperature and pH. Hydrogen concentrations were less than 0.1 vol.% in cooled dry gas. Corrosion rates and hydrogen production in PWR alkaline solution measured at pH 9.7 and 1500C were very high. AA 5052 alloy was the best material

  15. Quasi-static-dynamic formability of AA5052-O sheet under uniaxial and plane-strain tension

    LIU Da-hai; YU Hai-ping; LI Chun-feng

    2009-01-01

    An experimental study on the quasi-static-dynamic formability specified in electromagnetically assisted sheet metal stamping (EMAS) was presented. A series of uniaxial and plane-strain tensile experiments were carried out on AA5052-O sheet by using a combined quasi-static stretching and pulsed electromagnetic forming (EMF) method. Failure strains representing formability beyond conventional quasi-static forming limits are observed under both uniaxial tensile and plane-strain states. The total forming limits of the as-received aluminum alloy undergoing both low and high quasi-static pre-straining are almost similar in quasi-static-dynamic deformation. Ultimate total formability seems to depend largely on the high-velocity loading conditions. Thus, it appears that for quasi-static-dynamic deformation, the quasi-static pre-straining of material is not of primary importance to the additionally useful formability. These observations will enable to develop forming operations that take advantage of this improvement in formability, and will also enable the use of a quasi-static preform fairly close to the quasi-static forming limits without weakening its total formability for design of an EMAS process in shaping large aluminum shell parts like auto body panels.

  16. Friction surfacing of aluminium alloys

    Pereira, Diogo Jorge O. A.

    2012-01-01

    Friction surfacing is a solid state joining process that has attracted much interest in the past decades. This technology allows joining dissimilar metallic materials while avoiding the brittle intermetallic formations, involving temperatures bellow melting point and producing like forged metal structures. Much research using different steels has been made but the same does not happen with aluminium alloys, specially using different aluminium alloys. Friction surface coatings using cons...

  17. Impact Welding Structural Aluminium Alloys to High Strength Steels Using Vaporizing Foil Actuator

    Liu, B.; Vivek, A.; Daehn, G. S.

    2016-01-01

    Dissimilar Al/Fe joining was achieved using vaporizing foil actuator welding. Flyer velocities up to 727 m/s were reached using 10 kJ input energy. Four Al/Fe combinations involving AA5052, AA6111-T4, JAC980, and JSC1500 were examined. Weld samples were mechanically tested in lap-shear in three conditions: as-welded, corrosion-tested with ecoating, and corrosion-tested without coating. In all three conditions, the majority of the samples failed in the base aluminium instead of ...

  18. Friction Stir Welding of Al 5052 with Al 6061 Alloys

    Kumbhar, N. T.; Bhanumurthy, K.

    2012-01-01

    Friction stir welding (FSW), a solid-state joining technique, is being extensively used in similar as well as dissimilar joining of Al, Mg, Cu, Ti, and their alloys. In the present study, friction stir welding of two aluminium alloys—AA6061 and AA5052—was carried out at various combinations of tool rotation speeds and tool traverse speeds. The transverse cross-section of the weld was used for optical as well as electron microscopy observations. The microstructural studies were used to get an ...

  19. Recent developments in advanced aircraft aluminium alloys

    Highlights: • To compete with composites, performance of aluminium alloys should be increased. • Al–Li alloys have higher strength, fracture and fatigue/corrosion resistance. • Improvements of aerospace Al alloys are due to optimised solute content and ratios. • In selecting new materials, there should be no reduction in the level of safety. • The use of hybrid materials could provide additional opportunities for Al alloys. - Abstract: Aluminium alloys have been the primary material for the structural parts of aircraft for more than 80 years because of their well known performance, well established design methods, manufacturing and reliable inspection techniques. Nearly for a decade composites have started to be used more widely in large commercial jet airliners for the fuselage, wing as well as other structural components in place of aluminium alloys due their high specific properties, reduced weight, fatigue performance and corrosion resistance. Although the increased use of composite materials reduced the role of aluminium up to some extent, high strength aluminium alloys remain important in airframe construction. Aluminium is a relatively low cost, light weight metal that can be heat treated and loaded to relatively high level of stresses, and it is one of the most easily produced of the high performance materials, which results in lower manufacturing and maintenance costs. There have been important recent advances in aluminium aircraft alloys that can effectively compete with modern composite materials. This study covers latest developments in enhanced mechanical properties of aluminium alloys, and high performance joining techniques. The mechanical properties on newly developed 2000, 7000 series aluminium alloys and new generation Al–Li alloys are compared with the traditional aluminium alloys. The advantages and disadvantages of the joining methods, laser beam welding and friction stir welding, are also discussed

  20. Inhibition properties and adsorption behavior of imidazole and 2-phenyl-2-imidazoline on AA5052 in 1.0 M HCl solution

    Highlights: • IM and 2-PI show corrosion inhibition for AA5052 in HCl solution. • Synergistic effect between IM and 2-PI is observed and its mechanism is assumed. • Adsorption properties are estimated using ΔGads0, ΔHads0 and Ea, respectively. • Adsorption structures and inhibition mechanism for AA5052 are proposed. - Abstract: The inhibition behavior of imidazole (IM) and 2-phenyl-2-imidazoline (2-PI) for AA5052 was investigated by weight loss, electrochemical, contact angle measurements and scanning electron microscopy. The results show that IM and 2-PI can inhibit the corrosion of AA5052 and the inhibition efficiency of 2-PI is higher. The adsorption properties of them are estimated using ΔGads0, ΔHads0 and Ea. The results reveal that the adsorption processes are exothermic reactions mainly by a monolayer chemisorption mechanism, and follow Langmuir adsorption isotherm. The differences of the monolayer adsorption structure between IM and 2-PI on AA5052 surface are analyzed, and the inhibition mechanisms are proposed

  1. Effect of hydrogen on aluminium and aluminium alloys: A review

    Ambat, Rajan; Dwarakadasa, E.S.

    1996-01-01

    Susceptibility of aluminium and its alloys towards hydrogen embrittlement has been well established. Still a lot of confusion exists on the question of transport of hydrogen and its possible role in stress corrosion cracking. This paper reviews some of the fundamental properties of hydrogen in...... aluminium and its alloys and its effect on mechanical properties. The importance of hydrogen embrittlement over anodic dissolution to explain the stress corrosion cracking mechanism of these alloys is also examined in considerable detail. The various experimental findings concerning the link between...

  2. Shot peening of aluminium alloys

    Shot peening is a process of cold-hammering where a metallic surface is pelted with spherical grains. Each grain bumping into the surface acts as a hammer head and creates a small crater. The overlapping of these craters produces a residual compression layer just underneath the surface. It is well known that cracks cannot spread in a compression zone. In most cases of fatigue rupture and stress corrosion cracks propagate from the surface towards the inside so shot peening allows a longer lifetime of castings. Moreover most materials present a better resistance due to the cold-hammering effect of shot peening. Metallic surfaces can be treated in workshops or directly on site. Typical pieces that undergo shot peening on site are storing tanks, gas and steam turbines, tubes of steam generators and piping in oil or nuclear or chemical industries. This article describes shot peening from a theoretical and general point of view and presents the application to aluminium-lithium alloys. In the case of aluminium alloys shot peening can be used to shape the piece (peen-forming). (A.C.)

  3. Water atomised aluminium alloy powders

    Neikov, O.D.; Vasilieva, G.I.; Sameljuk, A.V.; Krajnikov, A.V

    2004-10-10

    The new rapid solidification (RS) process based on high-pressure water atomisation (WA) of the melt for manufacturing of advanced aluminium alloys was realised in the form of a pilot plant. The problems of safe operation in the course of Al alloy powder production and powder quality were solved by the use of water solutions of inhibitors, by the control of suspension temperature and hydrogen ion exponent (pH), by the hydraulic classification of atomised products, and by the optimisation of dehydration procedure. The rate of powder-water interaction strongly depends on the value of pH. While the rate of room temperature reactions is very slow at pH 3.0-4.0, the increase of pH to 6.0 leads to an intensive powder oxidation. A set of powder metallurgy (PM) alloys for various applications was produced on the base of water atomised powders. The characteristics of tensile strength of such alloys essentially exceed those of cast materials of similar compositions.

  4. Water atomised aluminium alloy powders

    The new rapid solidification (RS) process based on high-pressure water atomisation (WA) of the melt for manufacturing of advanced aluminium alloys was realised in the form of a pilot plant. The problems of safe operation in the course of Al alloy powder production and powder quality were solved by the use of water solutions of inhibitors, by the control of suspension temperature and hydrogen ion exponent (pH), by the hydraulic classification of atomised products, and by the optimisation of dehydration procedure. The rate of powder-water interaction strongly depends on the value of pH. While the rate of room temperature reactions is very slow at pH 3.0-4.0, the increase of pH to 6.0 leads to an intensive powder oxidation. A set of powder metallurgy (PM) alloys for various applications was produced on the base of water atomised powders. The characteristics of tensile strength of such alloys essentially exceed those of cast materials of similar compositions

  5. Effect of ZrB{sub 2} particles on the microstructure and mechanical properties of hybrid (ZrB{sub 2} + Al{sub 3}Zr)/AA5052 insitu composites

    Gautam, Gaurav, E-mail: gauravgautamm1988@gmail.com; Mohan, Anita, E-mail: amohan.app@iitbhu.ac.in

    2015-11-15

    Present study outlines the effect of ZrB{sub 2} particles variation on the morphology and mechanical properties of (ZrB{sub 2}+Al{sub 3}Zr)/AA5052Al alloy composites. Composites with varying amount of ZrB{sub 2} particles have been produced by direct melt reaction (DMR) technique. These composites have been characterized by X-ray diffractometer (XRD) and energy-dispersive spectroscopy (EDS) to confirm the presence of ZrB{sub 2} and Al{sub 3}Zr particles. Optical microscopy (OM) and scanning-electron microscopy (SEM) have been used to understand the morphology. To see the effect of ZrB{sub 2} variation on mechanical properties, hardness and tensile properties have been evaluated. The XRD and EDS results confirm the successful formation of ZrB{sub 2} particles in matrix of AA5052Al alloy. SEM and TEM studies exhibit that ZrB{sub 2} particles are mostly in hexagonal and some rectangular shape while Al{sub 3}Zr particles are in polyhedron and rectangular shapes. Most of ZrB{sub 2} particles are within a size range of 10–190 nm. Interface region is free of any impurity. OM studies show grain refinement of AA5052Al alloy matrix with formation of second phase ZrB{sub 2} particles. Tensile results indicate that the UTS and YS improve up to 3 vol.% of ZrB{sub 2} but beyond this composition a decreasing trend is observed. The strength coefficient increases with increase in ZrB{sub 2} particles up to 3 vol.% in the Al{sub 3}Zr/Al alloy composites, whereas strain hardening decreases. While beyond 3 vol.% ZrB{sub 2} particles in the Al{sub 3}Zr/Al alloy composite, opposite trend is observed in strength coefficient and strain hardening. Percentage elongation also improves with 1vol.% ZrB{sub 2}, but further addition of ZrB{sub 2} shows an adverse effect. However, a continuous increasing trend has been observed in bulk hardness. Fracture studies show facets of Al{sub 3}Zr particles and dimples of matrix, but with inclusion of ZrB{sub 2} dimple size decreases. Increase in Zr

  6. Investigation & Analysis of Different Aluminium Alloys t

    Nibedita Sethi*¹,; Ajit Senapati²

    2014-01-01

    Aluminium alloy LM-29, A-356 AND A-6060 was fabricated in sand casting method. Mach inability of aluminium alloy LM-29, A-356 AND A-6060 was investigated and evaluate the mach inability studying the different parameter such as cutting force, surface roughness, chip thickness, and power consumption during turning at different cutting speed and constant depth of cut and feed rate. In this paper also studies the mechanical properties means hardness, density and tensile strength o...

  7. Study on hardening mechanisms in aluminium alloys

    P. K. Mandal

    2016-01-01

    Full Text Available The Al-Zn-Mg alloys are most commonly used age-hardenable aluminium alloys. The hardening mechanism is further enhanced in addition of Sc. Sc additions to aluminium alloys are more promising. Due to the heterogeneous distribution of nano-sized Al3Sc precipitates hardening effect can be accelerated. Mainly, highlight on hardening mechanism in Al-Zn-Mg alloys with Sc effect is to study. In addition, several characterisations have been done to age-hardening measurements at elevated temperatures from 120oC to 180 oC. The ageing kinetics has also been calculated from Arrhenius equation. Furthermore, friction stir processing (FSP can be introduced to surface modification process and hardened the cast aluminium alloys. In this study, hardening mechanism can be evaluated by Vicker’s hardness measurement and mechanical testing is present task.

  8. Alloys oxidation of aluminium-scandium system

    Alloys and compounds of rare earth metals with aluminium thanks to their high corrosion stability, durability and small specific weight find to apply in various new techniques. On the base of carried out investigation it could be recommend as de oxidizing and alloying compositions containing 15-50 % of scandium as in possession of minimal oxidation

  9. Mechanical alloying of aluminium-lithium-magnesium alloy powders

    The production of high-purity aluminium-lithium-magnesium alloy powders, by mechanical alloying through grinding in a vibratory mill under high vacuum at room temperature, is described in details. The source materials for the grinding mixture were: aluminium-lithium alloy powder obtained by thermal vacuum-dehydrogenization of AlLiH4 hydride; magnesium metal powder; and chemically deoxidized aluminium metal powder. The implications which arose from the high reactivity of the component elements are discussed, and the measures taken to overcome them are described. The procedures used for the chemical analysis and powder characterization are given. (orig.)

  10. Friction Welding of Aluminium and Aluminium Alloys with Steel

    Andrzej Ambroziak

    2014-01-01

    Full Text Available The paper presents our actual knowledge and experience in joining dissimilar materials with the use of friction welding method. The joints of aluminium and aluminium alloys with the different types of steel were studied. The structural effects occurring during the welding process were described. The mechanical properties using, for example, (i microhardness measurements, (ii tensile tests, (iii bending tests, and (iv shearing tests were determined. In order to obtain high-quality joints the influence of different configurations of the process such as (i changing the geometry of bonding surface, (ii using the interlayer, or (iii heat treatment was analyzed. Finally, the issues related to the selection of optimal parameters of friction welding process were also investigated.

  11. Steam generated conversion coating on aluminium alloys

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    into functional conversion coatings in order to enhance corrosion resistance and adhesion to paint systems. Chromium based conversion coatings have been extensively used on aluminium alloys to improve adhesion of subsequent paint layers and corrosion resistance. However, the use of hexavalent chromium...

  12. Steam Initiated Surface Modification of Aluminium Alloys

    Din, Rameez Ud

    detailed analysis of the structure and morphology of the coating, and interface structure with and without organic top coat. Corrosion performance of the coatings was investigated using electrochemical methods, AASS, and FFC test. The morphology, microstructure, chemical composition, adhesion, and......The extensive demand of aluminium alloys in various industries such as in transportationis mainly due to the high strength to weight ratio, which could be translated into fuel economy and efficiency. Corrosion protection of aluminium alloys is an important aspect for all applications which includes......-friendly alternative processes. In the present work high temperature steam-based process has been investigated as a possible chromate free conversion coating. Investigations in the thesis includes the effect of alloy type, substrate microstructure, surface finish, and various chemistries on the coating formation, and...

  13. Softening Behaviour of Selected Commercially Pure Aluminium Model Alloys

    Sande, Gunnar

    2012-01-01

    A characterization of the softening behaviour of four different commercially pure aluminium alloys has been carried out. The work is related to the MOREAL project (Modelling towards value-added recycling friendly aluminium alloys), where the main goal is to quantify the effect of the elements in recyclable aluminium alloys on microstructure and mechanical properties during thermo-mechanical processing. Typical elements are iron (Fe), silicon (Si) and manganese (Mn), and the alloys studied in ...

  14. Steam Assisted Accelerated Growth of Oxide Layer on Aluminium Alloys

    Din, Rameez Ud; Yuksel, Serkan; Jellesen, Morten Stendahl; Møller, Per; Ambat, Rajan

    2013-01-01

    Corrosion resistance of aluminium alloys is related to the composition and morphology of the oxide film on the surface of aluminium. In this paper we investigated the use of steam on the surface modification of aluminium to produce boehmite films. The study reveals a detailed investigation of the...... effect of vapour pressure, structure of intermetallic particles and thickness of boehmite films on the corrosion behaviour of aluminium alloys....

  15. Mechanical behaviour of aluminium-lithium alloys

    N Eswara Prasad; A A Gokhale; P Rama Rao

    2003-02-01

    Aluminium-lithium alloys hold promise of providing a breakthrough response to the crying need for lightweight alloys for use as structurals in aerospace applications. Considerable worldwide research has gone into developing a range of these alloys over the last three decades. As a result, substantial understanding has been developed of the microstructure-based micromechanisms of strengthening, of fatigue and fracture as well as of anisotropy in mechanical properties. However, these alloys have not yet greatly displaced the conventionally used denser Al alloys on account of their poorer ductility, fracture toughness and low cycle fatigue resistance. This review aims to summarise the work pertaining to study of structure and mechanical properties with a view to indicate the directions that have been and can be pursued to overcome property limitations.

  16. FSW characterization of 6082 aluminium alloys sheets

    K. Mroczka; A. Pietras

    2009-01-01

    Purpose: The purpose of the investigations was to elaborate a set of FSW parameters for connecting 6082 aluminium alloy sheets allowing to produce welds of highest strength.Design/methodology/approach: The FSW was tried at different speeds and at additional cooling. The welds microstructure was studied using optical and scanning electron microscopes. The mechanical properties of produced connections are discussed regarding their tensile test and microhardness measurements.Findings: The FSW we...

  17. Perforation of aluminium alloy thin plates

    ANTOINAT, Léonard; Kubler, Régis; BAROU, Jean Luc; VIOT, Philippe; BARRALLIER, Laurent

    2015-01-01

    Low velocity perforation of aeronautical aluminium alloy sheets 2024 T3 is studied in this paper. After a literature review on recent experiments and models of plate’s perforation, experimental results for 2 thicknesses (2 mm and 4 mm) of plates are presented. Perforation tests are performed with an instrumented drop test. The striker has a large diameter and a conical shape nose. Two models for perforation are presented and calibrated to bring a better understanding of the experiments. The f...

  18. Friction factor of CP aluminium and aluminium–zinc alloys

    N Vidhya Sagar; K S Anand; A C Mithun; K Srinivasan

    2006-12-01

    Friction factor has been determined for CP aluminium and aluminium–zinc alloys using ring compression test at different temperatures from 303 K to 773 K. It is found that CP aluminium exhibits sticking whereas Al–Zn alloys do not exhibit sticking at elevated temperatures. Hot working of Al–Zn alloy is easier than that of CP aluminium at 773 K. As zinc content increases up to 10 wt% the friction factor decreases up to 0.02.

  19. Study of fatigue behaviour of 7475 aluminium alloy

    B B Verma; J D Atkinson; M Kumar

    2001-04-01

    Fatigue properties of a thermomechanically treated 7475 aluminium alloy have been studied in the present investigation. The alloy exhibited superior fatigue life compared to conventional structural aluminium alloys and comparable stage II crack growth rate. It was also noticed that the fatigue crack initiated from a surface grain and the crack extension was dominated by ductile striations. Analysis also revealed that this alloy possessed fracture toughness and tensile properties superior to that noticed with other structural aluminium alloys. Therefore the use of this alloy can safely reduce the overall weight of the aircraft.

  20. Corrosion of Metal-Matrix Composites with Aluminium Alloy Substrate

    B. Bobic; Mitrovic, S.; M. Babic; I. Bobic

    2010-01-01

    The corrosion behaviour of MMCs with aluminium alloy matrix was presented. The corrosion characteristics of boron-, graphite-, silicon carbide-, alumina- and mica- reinforced aluminium MMCs were reviewed. The reinforcing phase influence on MMCs corrosion rate as well as on various corrosion forms (galvanic, pitting, stress corrosion cracking, corrosion fatique, tribocorrosion) was discussed. Some corrosion protection methods of aluminium based MMCs were described

  1. Aluminium alloys containing iron and nickel

    The first part of this report addresses mechanism, kinetics and structure factors of aluminium alloys containing iron and nickel in water and high temperature steam. The studied alloys contain from 0.3 to 0.7 per cent of iron, and 0.2 to 1.0 per cent of nickel. Corrosion resistance and corrosion structure have been studied. The experimental installation, process and samples are presented. Corrosion structures in water at 350 C are identified and discussed (structure of corrosion products, structure of metal-oxide interface), and then in steam at different temperatures (350-395 C). Corrosion kinetics is experimentally studied (weight variation in time) in water at 350 C and in steam at different temperatures. Reactions occurring at over-heated steam (more than 400 C) are studied, and the case of welded alloys is also addressed. The second part addresses the metallurgical mechanism and processes influencing aluminium alloy resistance to corrosion by high temperature water as it appeared that separated phases protect the solid solution through a neighbourhood action. In order to avoid deep local corrosions, it seems necessary to multiply protective phases in an as uniform as possible way. Some processes enabling this result are described. They belong to conventional metallurgy or to powder metallurgy (with sintering and extrusion)

  2. Behaviour and design of aluminium alloy structural elements

    Su, Meini; 蘇玫妮

    2014-01-01

    Aluminium alloys are nonlinear metallic materials with continuous stress-strain curves that are not well represented by the simplified elastic, perfectly plastic material model used in most existing design specifications. The aims of this study are to develop a more efficient design method for aluminium alloy structures by rationally exploiting strain hardening. The key components of this study include laboratory testing, numerical modelling and development of design guidance for aluminium al...

  3. Aluminium Alloy Cast Shell Development for Torpedoes

    Vijaya Singh

    2005-01-01

    Full Text Available The sand-cast aluminium alloy cylindrical shells were developed for the advanced experimental torpedo applications. The components had intricate geometry, thin-walled sections, and stringent property requirements. The casting defects, such as shrinkage, porosity, incomplete filling of thin sections, cold shuts, inclusions and dimensional eccentricity, etc were found inthe initial castings trials. improvements in casting quality were achieved through modified methodology, selective chilling, risering, and by introducing ceramic-foam filters in the gatingsystem. The heat-treated and machined components met radiographic class I grade C/E standards, mechanical properties to BS1490 specifications, and leakage and hydraulic pressure testrequirements relevant for such applications.

  4. Roll casting of 5182 aluminium alloy

    Haga, T; M. Mtsuo; D. Kunigo; Hatanaka, Y; R. Nakamuta; H. Watari; S. Kumai

    2009-01-01

    Purpose: of this paper is investigation of the ability of the high speed roll casting of 5182 aluminium alloy. Appropriate twin roll caster to cast the 5182 strip was researched.Design/methodology/approach: Method used in the present study was an unequal diameter twin roll caster and a vertical type high speed twin roll caster equipped with mild steel rolls without parting material.Findings: are that the vertical type high speed twin roll caster was effective to cast 5182 strip at high speed....

  5. TEM microstructure investigations of aluminium alloys used for laser alloying

    K. Labisz

    2012-12-01

    Full Text Available Purpose: In this paper there are presented results of Transmission Electron Microscope investigation concerning the structure of the AlSi7Cu4 cast aluminium alloy using for alloying and remelting with the high power diode laser (HPDL. There are also presented the results of the thermo-derivative analysis performed using the UMSA (Universal Metallurgical Simulator and Analyser device, allowing to determine the specific points of the solidifying alloy, what is helpful for phase determination occurred in this alloy. In this work especially the changes of the precipitation type, size and shape were determined.Design/methodology/approach: The investigations were performed using electron microscopy for the microstructure and phases determination. By mind of the transmission electron microscopy, especially selected area diffraction method appliance it was possible to determine the phases occurred in the alloy in the as cast state. The morphology and size of the Mg2Si was also possible to determine as well the lattice parameters for this phase.Findings: : The reason of this work was also to present the laser treatment technology, which will be used for further alloying and remelting with ceramic powders – especially carbides and oxides. Particularly the overview will be directed on the laser power to achieve good layer hardness for protection of this hot work tool steel from losing their work stability and to make the tool surface more resistant to action in external conditions. The structure of the surface laser tray changes in a way, that there are very high roughness of the surface zone and the flatness or geometry changes in an important manner, crucial for further investigation.Research limitations/implications: The aluminium samples were examined metallographically using transmission electron microscope with different image techniques.Practical implications: Developing of new technology with appliance of Al alloys, High Power Diode Laser and

  6. Lubricated sliding wear behaviour of aluminium alloy composites

    J. C. Walker; Rainforth, W. M.; Jones, H.

    2005-01-01

    Interest in aluminium alloy (Al-alloy) composites as wear resistant materials continues to grow. However, the use of the popular Al-alloy-SiC composite can be limited by the abrasive nature of the SiC, leading to increased counterface wear rates. This study reports new Al-alloy composites that offer high wear resistance, to a level similar to Al-alloy-SiC. Aluminium alloy (2124, 5056) matrix composites reinforced by nominally 15 vol.% of Cr3Si, MoSi2, Ni3Al and SiC particles were prepared by ...

  7. Local electrochemical behaviour of 7xxx aluminium alloys

    F. Andreatta

    2004-01-01

    Aluminium alloys of the 7xxx series (Al-Zn-Mg-Cu) are susceptible to localized types of corrosion like pitting, intergranular corrosion and exfoliation corrosion. This represents a limitation for the application of these alloys in the aerospace components because localized corrosion might have a negative effect on safety and costs. This PhD thesis investigates the relation between electrochemical behaviour and microstructure of a number of 7xxx aluminium alloys: AA7075, AA7349 and an experime...

  8. Crystallographic orientation-spray formed hypereutectic aluminium-silicon alloys

    Hamilta de Oliveira Santos; Marilene Morelli Serna; Nelson Batista de Lima; Isolda Costa; Jesualdo Luiz Rossi

    2005-01-01

    Aluminium-silicon alloys have been wide accepted in the automotive, electric and aerospace industries. Preferred orientation is a very common condition for metals and alloys. Particularly, aluminium induces texture during the forming process. The preparation of an aggregate with completely random crystal orientation is a difficult task. The present work was undertaken to analyse the texture by X-ray diffraction techniques, of three spray formed hypereutectic Al-Si alloys. Samples were taken f...

  9. The dissolution and formation enthalpy of alloys and intermetallics of aluminium-lanthanum and aluminium-cerium systems

    Present article is devoted to dissolution and formation enthalpy of alloys and intermetallics of aluminium-lanthanum and aluminium-cerium systems. Therefore the dissolution temperatures of alloys and intermetallics of aluminium-lanthanum and aluminium-cerium systems were defined by means of calorimetry method. The enthalpy of formation of intermetallics of Al-Ce system was defined as well. The regularities in changes of dissolution and formation enthalpy of alloys and intermetallics depending on composition were studied.

  10. Effect of filtration on reoxidation proceses in aluminium alloys

    D. Bolibruchova

    2010-01-01

    Full Text Available This article is focused on reoxidation processes during filtration of aluminium alloys. Many of our experimental works pointed out, that using filtration media placed in gating system causes reoxidation of poured aluminium alloy. Main aim of our latest work was to validate our arguments, that filter in gating system can be considered as obstacle for continuous pouring, with help of computer simulations. This article is only a small part of our researches focused on reoxidation processes during filtration of aluminium alloys.

  11. Tribological characteristics of coatings on aluminium and its alloys

    Abdul-Mahdi, Fadhil S

    1987-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Hard anodising on aluminium and its alloys has been widely practised for many years in order to improve the resistance of the otherwise poor wear characteristics of aluminium. In recent years there has been an increasing interest in other treatments and coatings, on both aluminium and other base metals. The aim of this investigation is to explain the tribological performance and wear mechanis...

  12. Corrosion of Metal-Matrix Composites with Aluminium Alloy Substrate

    B. Bobic

    2010-03-01

    Full Text Available The corrosion behaviour of MMCs with aluminium alloy matrix was presented. The corrosion characteristics of boron-, graphite-, silicon carbide-, alumina- and mica- reinforced aluminium MMCs were reviewed. The reinforcing phase influence on MMCs corrosion rate as well as on various corrosion forms (galvanic, pitting, stress corrosion cracking, corrosion fatique, tribocorrosion was discussed. Some corrosion protection methods of aluminium based MMCs were described

  13. Influence of aluminium alloy type on dissimilar friction stir lap welding of aluminium to copper

    Galvão, I; Verdera, D; Gesto, D; Loureiro, A.; Rodrigues, D. M.

    2013-01-01

    A heat-treatable (AA 6082) and a non-heat treatable (AA 5083) aluminium alloys were friction stir lap welded to copper using the same welding parameters. Macro and microscopic analysis of the welds enabled to detect important differences in welding results, according to the aluminium alloy type. Whereas important internal defects, resulting from ineffective materials mixing, were detected for the AA 5083/copper welds, a relatively uniform material mixing was detected in the AA 6082/copper wel...

  14. Internal friction in iron-aluminium alloys having a high aluminium content

    By using a torsion pendulum to measure the internal friction of iron-aluminium alloys containing between 25 and 50 atom per cent of aluminium, it has been possible to show the existence of three damping peaks due to interstitial carbon. Their evolution is followed as a function of the carbon content, of the thermal treatment and of the aluminium content. A model based on the preferential occupation of tetrahedral sites is proposed as an interpretation of the results. A study of the Zener peak in these substitution alloys shows also that a part of the short distance disorder existing at high temperatures can be preserved by quenching. (author)

  15. Adhesive Bonding of Aluminium Alloy A5754 by Epoxy Resins

    Ivan Michalec

    2013-01-01

    Full Text Available Joining thin sheets of aluminium and its alloys is a promising area in the field of joining materials. Nowadays, joining methods that do not melt the material itself are increasingly being utilised. This paper deals with adhesive bonding of aluminium alloy A5754 by two-component epoxy resins. Theresults show that joints bonded by Hysol 9466 have appropriate mechanical properties, but that joints bonded by Hysol 9492 have better thermal stability.

  16. TORSIONAL DEFORMATION AND FATIGUE BEHAVIOUR OF 6061 ALUMINIUM ALLOY

    Marini Marno; Ahmad Badri Ismail

    2012-01-01

    Torsional deformation and fatigue behaviour of both solid and thin-walled tubular specimens were made from as-received and heat treated 6061 aluminium alloy were studied. 6061 aluminium alloy have been widely used as a candidate material in automobile, aerospace, aircraft and structural application because of their superior mechanical properties such as high strength to weight ratio, good ductility and others. The differences in cyclic deformation and fatigue behaviours between round and soli...

  17. Ball Pad Mold Electromagnetic Forming Process for Aluminium Alloy Sheet

    Wang, Wen-ping; Wu, Xiang-Dong; Wan, Min; Chen, Xiao-wei; Xiong, Wei-Ren

    2014-01-01

    In order to meet requirements of lightweight technology in the field of aerospace, the new forming technology for aluminium alloy skin parts and integral panel are brought to more attention. Based on the principle of electromagnetic forming (EMF) and energy distribution, a new electromagnetic forming process using ball as pad mold for aluminium alloy sheet forming was suggested and test apparatus was designed. The new method was verified by the finite element simulation and exp...

  18. Adhesive Bonding of Aluminium Alloy A5754 by Epoxy Resins

    Ivan Michalec; Milan Marônek

    2013-01-01

    Joining thin sheets of aluminium and its alloys is a promising area in the field of joining materials. Nowadays, joining methods that do not melt the material itself are increasingly being utilised. This paper deals with adhesive bonding of aluminium alloy A5754 by two-component epoxy resins. Theresults show that joints bonded by Hysol 9466 have appropriate mechanical properties, but that joints bonded by Hysol 9492 have better thermal stability.

  19. A study on the recycling of aluminium alloy 7075 scrap

    Oezer, Goekhan [Yildiz Technical Univ., Yildiz (TR). Balkan Centre of Advanced Casting Technologies (BACAT); Marsoglu, Muezeyyen [Yildiz Technical Univ., Yildiz (Turkey). Dept. for Metal and Materials Science Engineering; Burgucu, Sarp

    2012-07-01

    Aluminium and its alloys have recently become an important metal whose area and amount of usage increase more and more, due to their mechanical properties, recycling ability, and penetrability. If it is considered that the bauxite, which is the raw material of aluminium is rare on earth, and also the area and amount of aluminium usage increases over time, the importance of aluminium recycling goes up. aluminium recycling has become crucial by means of both, the potential of the scrap's dependant increase on usage and the primary aluminium production, as it is providing energy and cost savings. 7xxx grades of scrap are collected with other scrap of aluminium alloys in one turn and recycled all together. As the regain of these alloys is not done by isolation of the various grades, the finally recycled ingots result in lower grades. High value aluminium scrap is regrettably not recovered, as it was anticipated. This study is dealing with 7075 aluminium alloys originated from discharged blow molding tools and the rest piece cuttings of blocks and plates. The material has been subjected to an induction furnace, and has been remelted into small ingots and hardened according to 7075 aluminium alloy parameters (hardening aluminium tooling). [German] Aluminium und seine Legierungen sind in den letzten Jahren aufgrund ihrer mechanischen Eigenschaften, ihrer Recyclingfaehigkeit und ihrer Durchlaessigkeit immer bedeutendere metallische Werkstoffe geworden. Unter Beruecksichtigung, dass Bauxit als Rohmaterial selten auf der Erde vorkommt und der Verbrauch mit der Zeit steigt, waechst die Bedeutung des Recyclings von Aluminium. Aluminiumrecycling, zumal es Energieund Kosteneinsparungen ermoeglicht, ist sowohl fuer die schrottabhaengigen Verwendungspotentiale und die PrimaerAluminiumproduktion gleichermassen bedeutend geworden. Die 7xxxx Schrottlegierungen werden in einem Arbeitsgang mit dem Schrott aus anderen Aluminiumlegierungen gesammelt und recycled. Da die

  20. A Reaction Coating on Aluminium Alloys by Laser Processing

    Zhou, X.B.; De Hosson, J. Th. M.

    1993-01-01

    An aluminium oxide layer of 100 µm in thickness has been successfully coated on aluminium alloy 6061 and pure aluminium using a powder mixture of silicon oxide and aluminium by laser processing. A strong Al/Al2O3 interface was formed. The exothermic chemical reaction between SiO2 and Al may promote the metal/oxide wetting and the formation of Al2O3 layer. This new approach of ceramic coating on metals using a chemical reaction of other ceramics with metals may be applied to other systems.

  1. Radiation-induced creep of copper, aluminium and their alloys

    The results of creep studies on copper, aluminium and their alloys with and without neutron irradiation are presented. The experiments are carried out at the WWR-K reactor at the neutron fluence of 1.4.1016 n/m2.s (2.5.1016 n/m2.s, E>0.1 MeV). Polycrystalline copper (99.99 and 99.95%), aluminium (99.99%) and the alloys of copper with 4 at% of titanium, of aluminium with 4.2% of copper are studied within the temperature interval 0.31-0.51 Tm. (orig.)

  2. First wall design of aluminium alloy R-tokamak

    A design study of a low-activation D-T tokamak Reacting Plasma Project In Nagoya has been finished. The study emphasizes the vacuum vessel and the bumper limiter. Our choice of materials (aluminium vacuum vessel, copper conductors, aluminium TF coil case and lead shield) results in a radiation level of about 1 x 10-3 times that of a TFTR type design, and 1 x 10-4 times that of JET type design, at 2 weeks after one D-T shot. Thick graphite tiles will be fixed directly on the aluminium vacuum vessel using aluminium spring washers and bolts. With this simplified structure of the bumper limiter, the inner surface temperature of the thick aluminium vacuum vessel will be less than 1200C which is required to reduce the overaging effect of the aluminium alloy. (orig.)

  3. Local electrochemical behaviour of 7xxx aluminium alloys

    Andreatta, F.

    2004-01-01

    Aluminium alloys of the 7xxx series (Al-Zn-Mg-Cu) are susceptible to localized types of corrosion like pitting, intergranular corrosion and exfoliation corrosion. This represents a limitation for the application of these alloys in the aerospace components because localized corrosion might have a neg

  4. SOLUBILITY OF SILICON IN CAST ALUMINIUM ALLOY AFTER ELECTROHYDROPULSE TREATMENT

    Dyachenko, S.; Fedchenko, N.

    2006-01-01

    The structure of cast aluminium alloy AЛ9 exposed to electrohydropulse treatment (EHPT) was studied. It has been shown that after EHPT solubility of silicon in alloy matrix was increased. With the help of thermodynemic analysis the structural changes in metal after EHPT were explained.

  5. Residual stress in 7449 aluminium alloy forgings

    The through thickness residual stress distributions within three 120 mm thick rectilinear forgings, made from the high strength aluminium alloy 7449 have been measured using both neutron diffraction and deep hole drilling. Neutron diffraction measurements were made on two instruments, one using a pulsed spallation neutron source, the other a steady state reactor source. Heat treatment of the forgings included a rapid quench into cold water and it was the residual stresses arising from this step that were initially measured. Neutron diffraction measurements indicated large magnitude (>250 MPa) tensile residual stresses in the centre of an as quenched forging, balanced by surface regions stressed in compression (<-200 MPa). Sufficient measurements were made to permit the description of the residual stress distribution using area maps. Two forgings were stress relieved by cold compression immediately after quenching. The degree of plastic strain was either 2.5% or 4%, and was applied by a single application of force in the short transverse direction. Cold compressed forgings were found to have far lower residual stress when compared to the as quenched condition. The amount of cold compression was found to cause an insignificant difference in the final residual stress distribution. The neutron diffraction results are compared to measurements made by deep hole drilling and a new incremental variation of the technique. The deep hole was drilled through the centre of the forgings in the short transverse direction. Multiple neutron diffraction measurements were also made on the extracted cores from the deep hole measurements to assess the variation of the unstrained lattice parameter through the thickness of the forgings.

  6. Aluminium and its alloys: weldability, welding metallurgy; L'aluminium et ses alliages: soudabilite, metallurgie du soudage

    Boucher, Ch.

    2000-07-01

    The aim of this book is to give technological and use elements of the welding processes as well as the knowledge in weldability and metallurgy required for a better control of the welding of aluminium alloys. In the first part are detailed the generalities on aluminium alloys, their properties and uses sectors. The bases of the physical metallurgy of the aluminium alloys are dealt with too. The second part concerns the welding and the related techniques as well as the properties of the assemblies. Several supplements give useful data for the construction with aluminium alloys. This book is particularly devoted to engineers and technicians using or having to use for the first time the welding of aluminium alloys. (O.M.)

  7. Role of acidic chemistries in steam treatment of aluminium alloys

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    The effect of acidic chemistry on the accelerated growth of oxide on aluminium alloys Peraluman 706TM and AA6060 under exposure to high temperature steam was investigated. Studied chemistries were based on citrates and phosphates. Results showed that the presence of citrate and phosphate anions...

  8. Effect of Low Strain Rate on Formability of Aluminium Alloy

    Bidulská, J.; T. Kvačkaj; Bidulský, R.; Cabbibo, M.; Evangelista, E.

    2007-01-01

    Effect of low strain rate on formability of aluminium alloy 2014 by means of torsion test was performed. The presented experimental results exhibit decrease of the ductility with increase and decrease of ε and T, respectively, and optimal values of , ε T are thus obtained.

  9. Crystallographic orientation-spray formed hypereutectic aluminium-silicon alloys

    Hamilta de Oliveira Santos

    2005-06-01

    Full Text Available Aluminium-silicon alloys have been wide accepted in the automotive, electric and aerospace industries. Preferred orientation is a very common condition for metals and alloys. Particularly, aluminium induces texture during the forming process. The preparation of an aggregate with completely random crystal orientation is a difficult task. The present work was undertaken to analyse the texture by X-ray diffraction techniques, of three spray formed hypereutectic Al-Si alloys. Samples were taken from a billet of an experimental alloy (alloy 1 and were subsequently hot-rolled and cold-rolled (height reduction, 72% and 70%, respectively. The other used samples, alloys 2 and 3, were taken from cylinders liners. The results from the Laue camera showed texture just in the axial direction of alloy 3. The pole figures also indicated the presence of a typical low intensity deformation texture, especially for alloy 3. The spray formed microstructure, which is very fine, hinders the Al-Si texture formation during mechanical work.

  10. Weldability of high strength aluminium-scandium alloys

    Australia possesses a significant percentage of the world reserves of the ores required for the production of light alloys such as aluminium, magnesium and titanium. However, most of these minerals deposits are exported for processing, losing the potential of value adding benefits. Scandium has been known for some time to possess excellent grain refining properties when alloyed with aluminium. Although this adds considerable benefits to the mechanical properties of these alloys, it has not been fully exploited due to the high cost of producing the scandium metal. Deposits of scandium containing ore have recently been identified in Australia that are far more accessible than other deposits throughout the world. CSIRO Manufacturing Science and Technology had initiated a research project to investigate the effect of scandium and other grain refining additions on the properties of selected aluminium alloys in order to develop the market and maximise the potential benefits from Australian resources. The major objective of the project is to develop high strength aluminum alloys that exhibit good processing characteristics, particularly good weldability

  11. Effects and mechanisms of grain refinement in aluminium alloys

    K T Kashyap; T Chandrashekar

    2001-08-01

    Grain refinement plays a crucial role in improving characteristics and properties of cast and wrought aluminium alloys. Generally Al–Ti and Al–Ti–B master alloys are added to the aluminium alloys to grain refine the solidified product. The mechanism of grain refinement is of considerable controversy in the scientific literature. The nucleant effects i.e. which particle and its characteristics nucleate -Al, has been the subject of intensive research. Lately the solute effect i.e. the effect of dissolved titanium on grain refinement, has come into forefront of grain refinement research. The present paper attempts to review the literature on the nucleant effects and solute effects on grain refinement and addresses the importance of dissolved titanium in promoting nucleation of -Al on nucleant particles.

  12. Fatigue behaviour of 6061 aluminium alloy and its composite

    Hwa, Ping

    2001-01-01

    Fatigue behaviour of an artificial aged powder metallurgy 6061 aluminium alloy, and a composite made of this alloy with 15% volume fraction of SiCp was investigated. The alloy was subjected to T6 heat treatment, as was the composite material chosen (which incorporated SiC particles of average size 30pm). An extensive experimental programme was carried out in which fatigue lives were determined using load-controlled axial loading of unnotched cylindrical samples, at stress ratios of-1 and 0.1....

  13. TEM microstructure investigations of aluminium alloys used as coating substrate

    T. Tański

    2013-01-01

    Full Text Available Purpose: The aim of this paper was investigated structure and properties of gradient coatings produced in PVD process on AlSi9Cu aluminium alloys.Design/methodology/approach: The following results concern the structures of the substrates and coatings with the application of electron transmission and scanning microscopy; phase composition of the coatings using X-ray diffraction and grazing incident X-ray diffraction technique (GIXRD; microhardness and wear resistance.Findings: The deposited coatings are characterized by a single, double, or multi-layer structure according to the applied layers system, and the individual layers are coated even and tightly adhere to the substrate as well to each other. The analysis of coatings obtained on the surface of cast aluminium alloys by the PVD processes show a clear - over 100% - increase of the microhardness, compared to the base material microhardness.Practical implications: Achieving of new operational and functional characteristics and properties of commonly used materials, including the Al-Si-Cu alloys is often obtained by heat treatment, ie, precipitation hardening and/or surface treatment due to application or manufacturing of machined surface layer coatings of materials in a given group of materials used for different surface engineering processes.Originality/value: The paper presents the research involving the PVD coatings obtained on an unconventional substrate such as aluminium alloys. Contemporary materials should possess high mechanical properties, physical and chemical, as well as technological ones, to ensure long and reliable use. The above mentioned requirements and expectations regarding the contemporary materials are met by the non-ferrous metals alloys used nowadays, including the aluminium alloys.

  14. Aluminium-lithium alloys with scandium

    The influence of scandium on phase composition and properties of Al-Li alloys is considered. It is shown that the alloying with scandium increases strength properties, improves the weldability and affects the character and the velocity of decomposition of a supersaturated solid solution. The best compromise between strength and plastic properties is stated to be provided by combined introduction of Sc and Zr to Al-Li alloys

  15. Positron annihilation observations of shot peened aluminium alloys

    Samples of two aluminium alloys, 7075 and 2024, were used to examine the damage caused by surface shot peening. The 7075 alloy was in the T6 condition, which significs solution heat treatment and artificial aging to maximum hardness. The 2024 alloy was in the T3 condition, which signifies solution heat treatment followed by cold work. 2024 - T3 is quite sensitive to positron measurements of damage when compared with 7075 - T6 alloy. The main reason for the intensitivity of the 7075 - T6 to positron measurements is very likely the presence of a fully developed state of precipitation hardening as denoted by the T6 coding. The cold work used in the T3 condition did not bring the 2024 - T3 alloy above the upper limit of detectability for positron trapping prior to peening

  16. Metallurgical Characterisation of Recovered Aluminium Alloys in Cameroon

    T. Tchotang

    2013-07-01

    Full Text Available This article is a comparative study of metallurgical characteristics of the different aluminium alloys gotten through recycling of recovered aluminium in Cameroon. A simple experimental device for the foundry of secondary aluminium blend, of very good quality built around a movable charcoal furnace is presented. It enables better energy efficiency, a better distribution of the heat around the crucible and indirectly assures good quality of the products obtained, while respecting the economic constraints and users' safety. Six refining methods are proposed by the addition of polyvinyl chloride (method A, coke rich in carbon CHS (method C, ammonium chloride NH4Cl (method E, manganese dioxide MnO (method T, acrylic nitrite (C2H3Cln (method P and sodium chloride NaCl (method S. A critical analysis of the different recycling techniques is presented as well as a proposed process of melting and refining that enables the obtaining products with high degrees of purity. The results are then compared to the results obtained from the industrial methods of aluminium refining such as fractional crystallization (FC, granular filtration (GF and dissolution in a metal solvent (DS. The later (DS gives the rate of 6.540% of accumulated alloy elements and enables the best purification (93.460%, while the NaCl gives the lowest global rate of additive elements (9.478%, with the best purity index (90.522% amount the proposed methods. Results obtained show that this method of refining improves the metallurgical properties of secondary aluminium alloy blends and guarantees better safety, as well as reducing the risks of environmental pollution.

  17. TORSIONAL DEFORMATION AND FATIGUE BEHAVIOUR OF 6061 ALUMINIUM ALLOY

    marini marno

    2012-02-01

    Full Text Available Torsional deformation and fatigue behaviour of both solid and thin-walled tubular specimens were made from as-received and heat treated 6061 aluminium alloy were studied. 6061 aluminium alloy have been widely used as a candidate material in automobile, aerospace, aircraft and structural application because of their superior mechanical properties such as high strength to weight ratio, good ductility and others. The differences in cyclic deformation and fatigue behaviours between round and solid specimens where a stress gradient exist, and thin-walled tubular specimens where a uniform stress state is commonly assumed, are also discussed. Von Mises and Tresca criteria has been used to predict the monotonic and cyclic deformation curve and compared to the torsional data obtained from the experiment. The S-N curve was used to present and evaluate the fatigue life of the specimens. Through fractographic analysis, failure criteria of fracture surfaces were observed and discussed. 

  18. Gas accumulation at grain boundaries during 800 MeV proton irradiation of aluminium and aluminium-alloys

    Samples of pure aluminium (99.9999%) and commercial Al-2.7%Mg (AlMg3) and Al-1.1%Mg-0.5%Si (Al6061) alloys were irradiated with 800 MeV protons at the Los Alamos Meson Physics Facility (LAMPF) at a temperature between 40-1000C to a maximum dose of 0.2 dpa. Transmission electron microscopy (TEM) showed a complete absence of voids or bubbles in the grain interiors of the aluminium and the aluminium-alloys. Bubbles were clearly visible by TEM at grain boundaries in pure Al and the AlMg3 alloy; but bubbles were not visible in the Al6061 alloy. The bubble density in the AlMg3 alloy was considerably higher than in pure Al. The amount of gas accumulation at grain boundaries was found to depend on gas generation rate, alloying and cold-work microstructure. (orig.)

  19. Melting defect characterization in aluminium alloys by using computerized tomography

    This paper analyses the performance of parallel beam X-ray transmission computerized tomography, in the characterization of melting defects on a aluminium alloy. The results obtained presented a spatial resolution approximately of 0.8 mm. The porosity distribution existent in the piece appears as noise at the tomographic images with impossible detection. From the tomograms analyses it was possible to classify two defect regions at the pieces: empty and large pore concentration

  20. Wrought Aluminium Alloy Corrosion Propensity in Domestic Food Cooking Environment

    Adeosun, S. O.; E. I. Akpan; S. A. Balogun

    2012-01-01

    The study on corrosion behaviour of wrought aluminium alloy in domestic food cooking conditions has been examined using the gravimetric approach. Flat cold rolled and annealed sheets were subjected to solutions of Capsicum annuum, L. esculentum, Allium cepa, and their blend under three conditions, namely, heating and cooling in still air, heating and cooling in refrigerator, and leaving some in open still atmosphere. Results show that corrosion occurred within the test period (288 hours) in t...

  1. Outstanding inhibitive effect of colchicine on aluminium alloy 6061 corrosion

    Mudigere Krishnegowda Pavithra; Thimmappa Venkatarangaiah Venkateha; Mudigere Krishnegowda Punith Kumar; Nanjanagudu Subba Rao Anantha

    2015-01-01

    The corrosion protection ability of colchicine (CC) on Aluminium alloy 6061 (AA6061) in 3.5% NaCl medium was examined by potentiodynamic polarization, electrochemical impedance, and chronoamperometric techniques. About 99 % of protection efficiency was achieved by 2 mM concentration of CC in 3.5% NaCl solution.The adsorption of CC on AA6061 surface obeys Langmuir isotherm by following both physisorption and chemisorption mechanism. Variation in the surface morphology of inhibited and uninhibi...

  2. State diagram of copper-aluminium alloys after neutron irradiation

    It is ascertained that under reactor irradiation of copper-aluminium alloys (18.0-31.2 at% of Al) radiation-induced phase transformations occur, alpha-phase is decomposed into two ones with alpha'-phase precipitation, in gamma2-phase separate regions of its high-temperature disordered modification (gamma1-phase) are formed. Thermal stability of precipitations is investigated, regions of their existence are defined on the state diagram

  3. Oxidation of solid aluminium-magnesium alloy doped by scandium

    The oxidation of solid aluminium-magnesium alloy with scandium was studied by means of thermogravimetry method. The kinetic and energy parameters of oxidation process were defined. The kinetics of oxidation was studied by means of thermogravimetry method. The apparent activation energy was defined as well. The products of oxidation were studied by means of X-ray analysis method. It was shown that the main products of oxidation were γ-Al2O3 and Mg O.

  4. LASER CLADDING ON ALUMINIUM BASE ALLOYS

    Pilloz, M.; Pelletier, J; Vannes, A.; Bignonnet, A.

    1991-01-01

    laser cladding is often performed on iron or titanium base alloys. In the present work, this method is employed on aluminum alloys ; nickel or silicon are added by powder injection. Addition of silicon leads to sound surface layers, but with moderated properties, while the presence of nickel induces the formation of hard intermetallic compounds and then to an attractive hardening phenomena ; however a recovery treatment has to be carried out, in order to eliminate porosity in the near surface...

  5. Mechanical behaviour of nitrogen-implanted aluminium alloys

    Guzman, L. [Centro Materiali e Biofisica Medica, Trento (Italy); Bonini, G. [Dipt. di Ingegneria Nucleare del Politecnico, Milano (Italy); Adami, M. [Dipt. di Meccanica Strutturale, Univ. degli Studi di Trento (Italy); Ossi, P.M. [Dipt. di Ingegneria Nucleare del Politecnico, Milano (Italy)]|[Trento Univ., Povo (Italy). Dipt. di Fisica; Miotello, A. [Ist. Nazionale per la Fisica della Materia, Univ. degli Studi di Trento (Italy)]|[Trento Univ., Povo (Italy). Dipt. di Fisica; Vittori-Antisari, M. [ENEA, C.R. Casaccia, Settore Nuovi Materiali, Roma (Italy); Serventi, A.M. [ENEA, C.R. Casaccia, Settore Nuovi Materiali, Roma (Italy); Voltolini, E. [Centro Materiali e Biofisica Medica, Trento (Italy)

    1996-09-01

    The effect of nitrogen implantation into pure aluminium has been extensively explored, taking into account the variation of several physical and technological properties of the implanted layer. In particular, the formation of aluminium nitride, which occurs under specific choices of the implantation parameters, is associated with an increase in hardness. In this work, we consider two Al alloys (Al-7075 and Al-2011), frequently employed in the mechanical industry, with properties strongly dependent on the thermomechanical treatment. Molecular nitrogen bombardment at 150 keV (75 keV N{sup +}) was employed, up to a total dose of 3.10{sup 17} N cm{sup -2}, varying the substrate temperature from 373 to 473 K. The samples were then characterized with respect to composition, structure, morphology, microhardness, scratch resistance (also performing multi-pass testing) and friction coefficient. The results were interpreted within the framework of micromechanical models describing the hardness of thin coatings deposited onto soft substrates; the microhardness of the implanted layer increased by a factor of five. It appears that nitrogen-implanted aluminium alloy layers, in spite of their shallow thickness, behave better than hard TiN coated surfaces. Care must be taken to implant both alloys at the lowest possible temperature to avoid degradation of the substrate properties. (orig.)

  6. Improvement in Wear Properties of a Hypereutectic Aluminium Silicon Alloy with Manganese

    Prabhkiran Kaur; D.K. Dwivedi; P.M. Pathak; Sunil Kumar

    2014-01-01

    Improvement in wear properties of rare earth Cerium base hypereutectic Aluminium-Silicon alloy with Manganese modification has been reported in this paper. Wear studies were carried out on cast samples of hypereutectic Aluminium-Silicon alloy (Al-Si) with rare earth Cerium oxide (CeO2) and Manganese (Mn) modification. Final wear properties of rare earth Cerium oxide and Manganese modified hypereutectic Aluminium Silicon alloy were compared with the values of author?s previous work on rare ear...

  7. Sintering behaviour of Alumix 321 and 6061 aluminium alloys

    The sintering behaviour of two aluminium alloys, Alumix 321 and 6061, was studied in this paper. Both have a similar Mg, Cu and Si contents, but have been obtained by different methods. the Alumix 321 alloy is produced by mixing the initial elements as powders and the 6061 is obtained by water atomization. The work carried out includes the study of the green properties, the determination of the compressibility and green strength curves as well as the microstructural characterization of the powders. Thermal analyses (DTAs and Dilatometries) were performed in order to study the behaviour of both alloys with temperature. furthermore, different sintering temperatures were studied by characterizing the mechanical properties of the sintered materials. It can be concluded that the 6061 alloys has better properties than the Alumix 321, when both were sintered at 600 degree centigree. (Author) 27 refs

  8. Microstructure of Nitrided Aluminum Alloys Using an Electron-Beam-Excited-Plasma (EBEP)

    L. Liu; A. Yamamoto; T. Hishida; H. Shoyama; T. Hara; T. Hara

    2004-01-01

    Nitriding of surface of aluminum alloys was carried out with using an electron-beam-excited-plasma (EBEP)technique. The EBEP is sustained by electron impact ionization with energetic electron beam. Two kinds of substrates,aluminum alloys AA5052 and AA5083, were exposed to the down flow of EBEP source at 843 K for 45min. The specimens were characterized with respect to following properties: crystallographic structure (XRD), morphology (SEM) and the cross sectional microstructures of the nitrided layer was observed using a scanning electron microscopy (SEM). There are some Al2O3 particles on the surface of the nitrided AA5052 and AA5083. The AIN layers were formed on the substrates with the thickness of 4.5 μ m for AA5052 and 0.5 μ m for AA5083. A relatively uniform nitrided surface layer composed of AIN can be observed on the AA5052 substrate. The grains size near the interfaces between the substrate and AIN layer were smaller than that near the surface. On the surface of AIN layer, the concentration of nitrogen was high and in the middle of AIN layer it had a constant concentration like the aluminum and the concentration was decreased with approaching to the interface. On the surface of nitrided AA5083, a uniform AIN layer was not formed as the reason for the high nitriding temperature.

  9. Thixoextrusion of A357 aluminium alloy

    Forn Alonso, Antonio; Vaneetveld, Gregory; PIERRET, Jean-Christophe; Menargues Muñoz, Sergi; Baile Puig, Maria Teresa; Campillo Betbese, Manel; RASSILI, Ahmed

    2010-01-01

    The aim of this work is to attempt the application of A357 Al-Si-Mg cast alloy in the thixoextrusion process, evaluating the different forming parameters effect. Thixoextrusion offers several advantages compared with traditional hot-extrusion such as lower pressure, minor friction forces, higher material fluidity and longer tool life. This type of semi-solid process requires high solid fraction (0.7

  10. Superplastic blow forming of 2219 aluminium alloy

    Kaibyshev, R.; Kazakulov, I.; Gromov, D. [Inst. for Metals Superplasticity Problems, Ufa (Russian Federation); Lesuer, D.R.; Nieh, T.G. [Lawrence Livermore National Lab., Livermore, CA (United States)

    2004-07-01

    Superplasticity in 2219 aluminum alloy was achieved through thermomechanical processing. Tension tests showed that the alloy exhibits superplastic behavior in the temperature range of 450-540 C and strain rates ranging from 2.2 x 10{sup -5} to 1.1 x 10{sup -1} s{sup -1}. A maximum elongation-to-failure of 670% was recorded at 500 C and at the initial strain rate of 2.2 x 10{sup -4} s{sup -1}. High cavitation level and intensive grain growth were observed. Sheet of the 2219 aluminum alloy was blow formed into conical shape using two different methods: simple negative and backpressure forming. A strain of 2.1 was obtained at 500 C under the backpressure blow forming condition. It was found that elongation to failure under blow forming with backpressure is about 1.5 times higher than that under a simple female forming. Microstructural evolution of blow formed parts was also examined. (orig.)

  11. Aluminium. II - A review of deformation properties of high purity aluminium and dilute aluminium alloys.

    Reed, R. P.

    1972-01-01

    The elastic and plastic deformation behavior of high-purity aluminum and of dilute aluminum alloys is reviewed. Reliable property data, including elastic moduli, elastic coefficients, tensile, creep, fatigue, hardness, and impact are presented. Single crystal tensile results are discussed. Rather comprehensive reference lists, containing publications of the past 20 years, are included for each of the above categories. Defect structures and mechanisms responsible for mechanical behavior are presented. Strengthening techniques (alloys, cold work, irradiation, quenching, composites) and recovery are briefly reviewed.

  12. Recycling of Glass Fibre Reinforced Aluminium Laminates and Silicon Removal from Aerospace Al Alloy

    Zhu, G.

    2012-01-01

    Aerospace aluminium alloys (7xxx and 2xxx series Al alloy) is one of the important Al alloys in our life. The recycling of aerospace Al alloy plays a significant role in sustainable development of Al industry. The fibre reinforced metal laminates GLARE including 67 wt.% 2024 Al alloy was used as upp

  13. A super-ductile alloy for the die-casting of aluminium automotive body structural components

    Watson, D.; Ji, S; Fan, Z.

    2014-01-01

    Super-ductile die-cast aluminium alloys are critical to future light-weighting of automotive body structures. This paper introduces a die-cast aluminium alloy that can satisfy the requirements of these applications. After a review of currently available alloys, the requirement of a die-cast aluminium alloy for automotive body structural parts is proposed and an Al-Mg-Si system is suggested. The effect of the alloying elements, in the composition, has been investigated on the microstructure an...

  14. Enhancement of wear and ballistic resistance of armour grade AA7075 aluminium alloy using friction stir processing

    I. Sudhakar; V. Madhu; G. Madhusudhan Reddy; K. Srinivasa Rao

    2015-01-01

    Industrial applications of aluminium and its alloys are restricted because of their poor tribological properties. Thermal spraying, laser surfacing, electron beam welding are the most widely used techniques to alter the surface morphology of base metal. Preliminary studies reveal that the coating and layering of aluminium alloys with ceramic particles enhance the ballistic resistance. Furthermore, among aluminium alloys, 7075 aluminium alloy exhibits high strength which can be compared to tha...

  15. Subgrain Growth, Recovery Kinetics and Nucleation of Recrystallization of Cold Deformed Aluminium Alloys

    Bunkholt, Sindre

    2013-01-01

    Phenomena related to annealing of aluminium alloys are among the least understood in aluminium metallurgy but very important for industrial thermo-mechanical processing i.e. deformation and annealing. Physical models are used to predict recovery and recrystallization behaviour, and associated material properties, industrially. However, alloy development, e.g. to incorporate more recycled aluminium, has shown that current softening models are not satisfactory. Thus, improvements do require a b...

  16. Slip lines in scandium and lithium containing aluminium alloys

    Intensive slip lines in cold rolled sheets of scandium or lithium containing aluminium base alloys are under study. Slip lines are shown to be the places of concentrated shear strain which arise due to the occurrence of secondary δ'(Al3Li) and Al3Sc particles completely coherent to the matrix. The formation of slip lines has a detrimental effect on cold rolled sheet mechanical properties after heat hardening. To avoid the appearance of slip lines it is necessary to roll sheets with low reductions in area and to choose appropriate conditions of intermediate heat treatments. 5 refs., 5 figs., 2 tabs

  17. The fracture of boron fibre-reinforced 6061 aluminium alloy

    Wright, M. A.; Welch, D.; Jollay, J.

    1979-01-01

    The fracture of 6061 aluminium alloy reinforced with unidirectional and cross-plied 0/90 deg, 0/90/+ or - 45 deg boron fibres has been investigated. The results have been described in terms of a critical stress intensity, K(Q). Critical stress intensity factors were obtained by substituting the failure stress and the initial crack length into the appropriate expression for K(Q). Values were obtained that depended on the dimensions of the specimens. It was therefore concluded that, for the size of specimen tested, the values of K(Q) did not reflect any basic materials property.

  18. Determination of phosphorus in hypereutectic aluminium-silicon alloys.

    Mukai, K

    1972-04-01

    A reproducible method is described for determination of small amounts of phosphorus (from 0.0005% to 0.02%) in hypereutectic aluminium-silicon complex alloys. The method permits the separate determination of phosphorus in acid-soluble and acid-insoluble fractions. Phosphomolybdate is extracted with n-butanol-chloroform solvent mixture and back-extracted with a btannous chloride reducing solution. The phosphorus content of a sample cut into small pieces decreases during storage; loss of phosphorus is negligible on acid dissolution under oxidizing conditions. PMID:18961077

  19. Friction stir welding of 6061 aluminium alloy

    6061 AA (Al-Mg-Si alloy) has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to-weight ratio and good corrosion resistance such as marine frames, pipelines, storage tanks, and aircraft components [1]. It is also used for the manufacturing of fuel elements in the nuclear research reactors. Compared to many of the fusion welding processes that are routinely used for joining structural alloys, friction stir welding (FSW) is a solid state joining process in which the material that is being welded is not melted and recast [2]. The welding parameters such as tool rotational speed, welding traverse speed, and tool profile play a major role in deciding the weld quality. Several FSW tools (differ from each other in pin angle, shoulder diameter, and shoulder concavity) have been used to fabricate a number of joints in order to obtain a tool with which a sound weld can be produced. It was found that the FSW tool with tapered cone pin, concave shoulder, and shoulder diameter equal to four times the welded plate thickness is suitable to produce a sound weld. The effect of the traverse speed on the global and local tensile properties of friction stir welded joints has been investigated in the 6061-T6 AA. The global tensile properties of the FSW joints were improved with increasing the traverse speed at constant rotation rate. It is found that the global tensile strength of the FSW joint is limited by the local tensile strength of the nearest region to the weld center at which the cross section is composed mainly of the HAZ. The effect of the initial butt surface on the formation of the zigzag line on the tensile properties of the welds was examined by using three types of welding samples differ in the preparation of the initial butt surface. The first type of samples welded without removing the oxide layer from the initial butt surface (uncleaned butt surfaces joint). In the second type of samples the oxide layer was removed from

  20. Precipitation kinetics of Si in aluminium alloys

    The precipitation kinetics of Si in an Al-1.7 wt.%Si alloy after different thermal treatments has been studied by means of transmission electron microscopy (TEM), dilatometry and differential scanning calorimetry (DSC). The results obtained are explained by a model based on simple nucleation and growth/dissolution laws and are compared with measured precipitate size distributions. The evolution of precipitates in water-quenched samples during linear heating depicts the exothermic formation of platelets and globular Si precipitates (200-300 deg. C). The endothermal dissolution of Si platelets starts at lower temperatures than that of the globular precipitates. Coarsening and finally dissolution of globular precipitates is observed with increasing temperature. Samples slowly cooled from the solution treatment temperature present mostly globular precipitates, which are nucleated during cooling. Here, an exothermal effect related to the growth of Si precipitates increasing their volume fraction is observed at relatively high temperatures (350-460 deg. C) during linear heating. The formed precipitates are stable up to ∼460 deg. C, where the modelled critical radius becomes bigger than most of the Si precipitates formed so far

  1. Modelling technological properties of commercial wrought aluminium alloys

    The purpose of this paper is to model three important technological properties for aluminium alloys, based on their performance indices. The models are based on the chemical compositions and microstructure characteristics which are calculated using thermodynamical calculations. The properties that were modelled are the general corrosion, the weldability (MIG and TIG) and the machinability. The results from these models are to be used in materials selection and optimisation. The models clearly show that the general corrosion resistance is reduced for all alloy additions, except for small amounts of titanium. The largest influence on the corrosion is from copper and zinc. The weldability is negatively influenced by the copper and zinc-content, and for small additions of zirconium and titanium it is increased. The machinability is positively influenced by the hardness of the alloy or by adding lead or bismuth. For the non-heat-treatable alloys there was no influence from the composition to the corrosion resistance or the weldability. Copper and zinc which are added to increase the strength to the alloy strongly reduce both the weldability and the corrosion resistance but due to the increase in hardness increase the workability.

  2. About resonance frequencies of aluminium alloy bending vibrations

    Using ultrasonic method resonance frequencies of bending vibrations and elastic moduli of aluminium alloy SAV-1 samples are investigated. On the base of spectra of bending vibrations in low-frequency range data on values of a number of elastic properties are obtained as well as dispersion characteristics of main moduli for number of frequencies before and after ionizing irradiation (60Co, 5x103-1.6x107 Gy) of samples. Considerable stability of sample elastic moduli during common storage conditions and nonlinear dose dependence of these parameters within wide range of absorbed doses are pointed out. Possible causes of revealed effects of radiation modification of elastic properties of SAV-1 alloy are analyzed

  3. Frictional conditions between alloy AA6060 aluminium and tool steel

    Widerøe, Fredrik; Welo, Torgeir

    2011-05-01

    The frictional conditions in the new process of screw extrusion of aluminium have been investigated. The contact behaviour between the aluminum alloy and the tool steel in the extruder is vital for understanding the extrusion process. Using a compressive-rotational method for frictional measurements the conditions for unlubricated sticking friction between aluminum alloy AA6060 and tool steel at different combinations of temperatures and pressures have been investigated. In this method the samples in the form of disks are put under hydrostatic pressure while simultaneously being rotated at one end. Pins made from contrast material have been inserted into the samples to measure the deformation introduced. This approach along with 3D simulations form a method for determining the frictional conditions. The paper describes the test method and the results. It was found that the necessary pressure for sticking to occur between the aluminum AA6060 and the different parts of the extruder is heavily influenced by the temperature.

  4. Frictional conditions between alloy AA6060 aluminium and tool steel

    The frictional conditions in the new process of screw extrusion of aluminium have been investigated. The contact behaviour between the aluminum alloy and the tool steel in the extruder is vital for understanding the extrusion process. Using a compressive-rotational method for frictional measurements the conditions for unlubricated sticking friction between aluminum alloy AA6060 and tool steel at different combinations of temperatures and pressures have been investigated. In this method the samples in the form of disks are put under hydrostatic pressure while simultaneously being rotated at one end. Pins made from contrast material have been inserted into the samples to measure the deformation introduced. This approach along with 3D simulations form a method for determining the frictional conditions. The paper describes the test method and the results. It was found that the necessary pressure for sticking to occur between the aluminum AA6060 and the different parts of the extruder is heavily influenced by the temperature.

  5. Image analysis used for aluminium alloy microstructure investigation

    M. Krupiński

    2010-09-01

    Full Text Available Purpose: In this work the metallographic microstructure analysis of the investigated AlSi7Cu3Mg aluminium cast alloy was performed for samples cooled with different cooling rate settings. The preformed investigations are subjected to the analysis of cooling rate influence on the phase morphology.Design/methodology/approach: The solidification process itself is analysed using the UMSA device by appliance of the Derivative Thermo Analysis. The influence of the cooling rate on the alloy microstructure was investigated using computer aided image analysis, in this work also the content of particular phases was analysed, as well the percentage of pinholes compared to the chosen cooling rate.Findings: The treated sample is without holes, cracks and defects as well as has a slightly higher hardness value compared to the as-cast material.Research limitations/implications: The investigated samples were made of the cylindrical shape and were cooled in the range of 0.2°C/s to 1.25°C/s. In this work also the derivative thermoanalysis was performed to determine the correlation between the chosen cooling rate and the microstructure as well changes in the derivative curve shape. For alloy cooling with chosen cooling rate as well for the derivative thermo-analysis the UMSA analysator was applied.Practical implications: The investigated material can find its use in the foundry industry; an improvement of component quality depends mainly on better control over the production parameters.Originality/value: The originality of this work is based on applying of regulated cooling rate of aluminium alloy for structure and mechanical properties changes. As an effect of this study it will be possible to understand and to influence the mechanism of structure forming, refinement and nucleation. Also a better understanding of the thermal characteristics will be provided to achieve a desirable phase morphology required for application of this material under production

  6. Solidification and precipitation in aluminium-zirconium alloys. Pt. 1

    The cast structure and the precipitating primary phases were investigated in Al-Zr alloys on the basis of high-purity Aluminium with 0.1 to 1.2 wt.% Zr after fast solidification in a watercooled mold. With higher Zr-saturation of the melt the tetragonal ZrAl3-equilibrium phase appears, which is already known from slowly cooled samples. In alloys with lower Zr-supersaturation with respect to the raised Zr-solubility of about 0.6 wt.% due to the fast solidification there appears solely or additionally the new metastable cubic ZrAl3-phase as the primary precipitation. The particles show cubic or fourfold symmetric star form and have nearly the same lattice parameters as Aluminium. By coherent epitaxi of the Al-lattice they act as prefered nuclei for the solidification of the α-phase. Consequently an intensive grain refining takes place in a critical concentration range depending on temperature of pouring and cooling rate. (orig.)

  7. Contradictory effect of chromate inhibitor on corrosive wear of aluminium alloy

    Research highlights: → Corrosive wear of aluminium alloy in inhibited artificial acid rain was studied. → Tribometer with linear reciprocating ball-on-flat geometry was used.→ Corrosion potential, polarization current and friction coefficient were measured. → Chromate decreases corrosion of aluminium alloy under wear conditions. → Chromate in general accelerates corrosive wear of the alloy in acid rain. - Abstract: The corrosive wear of D16T aluminium alloy in artificial acid rain was studied. A special tribometer with the linear reciprocating ball-on-flat geometry was used. The setup allows to measure simultaneously an open circuit potential, to carry out potentiostatic and potentiodynamic polarization studies of the alloy corrosion and to record the friction coefficient. It was established that the addition of strontium chromate inhibitor to the working environment decreases an electrochemical corrosion of the aluminium alloy under wear conditions, but in general accelerates its destruction due to insufficient wear resistance of a formed surface film.

  8. Laser surface alloying of aluminium-transition metal alloys

    Almeida, A.

    1998-04-01

    Full Text Available Laser surface alloying has been used as a tool to produce hard and corrosion resistant Al-transition metal (TM alloys. Cr and Mo are particularly interesting alloying elements to produce stable highstrength alloys because they present low diffusion coefficients and solid solubility in Al. To produce Al-TM surface alloys a two-step laser process was developed: firstly, the material is alloyed using low scanning speed and secondly, the microstructure is modified by a refinement step. This process was used in the production of Al-Cr, Al-Mo and Al-Nb surface alloys by alloying Cr, Mo or Nb powder into an Al and 7175 Al alloy substrate using a CO2 laser. This paper presents a review of the work that has been developed at Instituto Superior Tecnico on laser alloying of Al-TM alloys, over the last years.

    En el presente trabajo se estudia la aleación superficial mediante láser de aluminio con metales de transición. El cromo y el molibdeno son particularmente interesantes porque producen aleaciones de alta resistencia y por el bajo coeficiente de difusión y solución sólida en aluminio. Para producir estas aleaciones se ha seguido un procedimiento desarrollado en dos partes. En primer lugar, el material se alea usando una baja velocidad de procesado y en segundo lugar la estructura se modifica mediante un refinamiento posterior. Este procedimiento se ha empleado en la producción de aleaciones Al-Cr, Al-Mo y Al-Nb mediante aleación con láser de CO2 de polvos de Cr, Mo o Nb en aluminio y la aleación 7175. Este trabajo es una revisión del desarrollado en el Instituto Superior Técnico de Lisboa en los últimos años.

  9. Low temperature oxidation of niobium alloy with silicon-aluminium coating

    Using the gravimetry methods heat resistance of niobium-titanium-aluminium alloy in the air and at 700 deg C in the initial state and when it is protected by silicide-aluminium coatings (with variable content of aluminium) is investigated. Using X-ray diffraction and micro X-ray diffraction analyses, mechanisms of the alloy oxidation and the coating protective effect are studied. The role of aluminium in the formation of coatings is analyzed and according to bend tests the plasticity of the coatings is evaluated

  10. Thermoelectric power in low-density interstitial-free iron-aluminium alloys

    Rana, Radhakanta; Liu, Cheng

    2013-09-01

    Thermoelectric power (TEP) studies on low-density interstitial-free iron-aluminium alloys reveal that the TEP decreases with increase in the aluminium content on account of the introduction of lattice dispersion centres. The TEP coefficients, determined from the Nordheim-Gorter law, for 6.8 and 8.1 wt.% aluminium additions to α-iron are found to be higher than values reported in previous literature for small aluminium additions. The grain size has a very weak effect on the TEP of these alloys.

  11. Corrosion Behaviour of Friction Stir Welded AA5xxx Aluminium Alloys

    Abuaisha, Ramadan R

    2013-01-01

    Friction stir welding (FSW) is a well recognised method for joining aluminium alloys and other engineering materials at a temperature below their melting point. However, the microstructure of the alloys may be modified during the welding process due to frictional heat and severe plastic deformation.In this study, the microstructures of friction stir welded AA5754-H111 and AA5083-O aluminium alloys have been investigated using optical microscopy, transmission and scanning electron microscopy e...

  12. A study of the anodic behaviour of aluminium alloys in alkaline electrolytes

    Walters, B N

    1988-01-01

    Recent studies an the discharge performance of aluminium alloys in alkaline media have led to improved alloys with significantly lower corrosion rates and more anodic potentials. Performance, of various alkaline electrolytes have also been examined and considerable progress has been made in this area. A review of the available literature reveals a list of several elements which are suitable for alloying with aluminium as regards reducing corrosion and overpotential. Previous work at the Chemi...

  13. Ultrasonic Welding of Aluminium to Titanium: Microstructure, Properties, and Alloying Effects

    Zhang, Chaoqun

    2015-01-01

    Use of welded titanium alloy to aluminium alloy structures in the aerospace industry has a number of potential benefits for both cost and weight saving by enabling titanium to be used only in the most critical parts, with the cheaper and lighter aluminum alloy making up the rest of the structure. However, due to the formation of brittle intermetallic compounds (IMC) at interface and the enormous gap in melting point, the welding of titanium to aluminium remains a major challenge. Solid state ...

  14. Microstructure and mechanical properties of thixoformed A319 aluminium alloy

    Highlights: • A319 was successfully thixoformed at 50% liquid, i.e. at 571 °C. • T6 heat treatment has increased the strength and hardness of the thixoformed alloy. • The elongation after T6 heat treatment is even significantly improved. • The iron-rich intermetallic phase reduces the strength of the thixoformed alloy. - Abstract: Thixoforming is a viable technology for forming alloys in a semisolid state into near net-shaped products. In the present study, the effect of a thixoforming process on the microstructure and mechanical properties of A319 aluminium alloy was investigated. The ingots obtained from the cooling slope were thixoformed in a press after they remained at 571 °C for 5 min, yielding a microstructure predominantly composed of α-Al globules and inter-globular Si particles. Some of the thixoformed samples were treated with an ageing process (T6) and then, hardness and tensile samples were prepared from the as-cast, as-thixoformed and thixoformed T6. All the thixoformed samples were characterised using optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) as well as hardness measurements and tensile tests. The results indicate that the mechanical properties of the thixoformed A319 alloy increased after the T6 heat treatment (hardness of 124.2 ± 3.2 HV, tensile strength of 298 ± 3.0 MPa, yield strength of 201 ± 2.6 MPa and elongation to fracture of 4.5 ± 0.3%). The fracture samples from the tensile test were analysed, revealing that the iron-rich intermetallic observed in the samples reduced the tensile strength and ductility of the thixoformed A319 alloys

  15. PROCESS CAPABILITY STUDY OF A RAPID CASTING SOLUTION FOR ALUMINIUM ALLOYS USING THREE-DIMENSIONAL PRINTING

    R. Singh

    2011-12-01

    Full Text Available In the present work, the best shell wall thickness of a mould cavity was investigated in a process capability study of a rapid casting solution for aluminium alloys using three-dimensional printing (3DP. Starting from the identification of a component/benchmark, an aluminium-alloy casting prototype was produced with different shell wall thicknesses by three dimensional printing. The results of the study suggest that, at the best shell wall thickness (5 mm for aluminium alloys, the rapid casting solution using a 3DP process lies within the ±3.999 sigma (σ limit.

  16. Selected properties of the aluminium alloy base composites reinforced with intermetallic particles

    M. Adamiak

    2005-01-01

    Purpose: The main aim of this work is to investigate two types of intermetallics TiAl and Ti3Al as reinforcement and their influence on selected properties and microstructure of aluminium matrix composites.Design/methodology/approach: Aluminium matrix composites were produced employing the atomised aluminium alloy AA6061 as metal matrix, when as reinforcement TiAl and Ti3Al intermetallics particles were used. The powders were cold pressed and then hot extruded. To evaluate the effect of mecha...

  17. Electrodeposition of aluminium film on P90 Li-Al alloy as protective coating against corrosion

    U. Bardi; Caporali, S; M. Craig; A. Giorgetti; Perissi, I; Nicholls, J. R.

    2009-01-01

    In this paper we report on the electrodeposition of thin aluminium layers on P90 lithium–aluminium alloy at room temperature from a chloroaluminate ionic liquid (1-butyl-3-methyl imidazolium heptachloroaluminate [BMIm]Al2Cl7). We found that the treatment of the P90 sample's surface is a key point to obtain good quality coatings. On freshly mechanically polished surfaces, thin (about 24 µm), homogeneous and dense aluminium layers were obtained at 10 µm h− 1 deposition rate. F...

  18. Fabrication And Mechanical Properties Of A Nanostructured Complex Aluminum Alloy By Three-Layer Stack Accumulative Roll-Bonding

    Lee S.-H.

    2015-06-01

    Full Text Available A multi-layered complex aluminum alloy was successfully fabricated by three-layer stack accumulative roll bonding(ARB process. The ARB using AA1050 and AA5052 alloy sheets was performed up to 7 cycles at ambient temperature without lubrication. The specimen processed by the ARB showed a multi-layer aluminum alloy sheet in which two aluminum alloys are alternately stacked. The grain size of the specimen decreased with the number of ARB cycles, became about 350nm in diameter after 7cycles. The tensile strength increased with the number of ARB cycles, after 6c it reached 281MPa which is about twice higher than that of the starting material. The microstructures and mechanical properties of a three-layer AA1050/AA5052 alloy fabricated by the ARB were compared to those of the conventional ARB-processed material.

  19. Characteristics of electric parameters in aluminium alloy MAO coating process

    Long, B H [College of Physics and Department of Materials Science, Jilin University, Changchun 130021 (China); Wu, H H [College of Physics and Department of Materials Science, Jilin University, Changchun 130021 (China); Long, B Y [College of Physics and Department of Materials Science, Jilin University, Changchun 130021 (China); Wang, J B [National Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Wang, N D [College of Physics and Department of Materials Science, Jilin University, Changchun 130021 (China); Lue, X Y [National Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Jin, Z S [National Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China); Bai, Y Z [State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Department of Physics, Dalian University of Technology, Dalian 116024 (China)

    2005-09-21

    Characteristics of electric parameters in the microarc oxidation (MAO) process of aluminium alloy at constant voltage were studied by a homemade data collecting system. The experimental results show that (1) the variations of the cathodic and anodic current amplitudes and the effective working current reflect obviously five different stages in the course of treatment and (2) variations of the dynamic forward resistance and electric resistivity of coatings have different stages too, while changes of the dynamic backward resistance and resistivity with treatment time are not evident. During the MAO process, the dynamic forward resistance is not equal to the backward resistance at any time, and the former is generally greater than the latter. Scanning electron microscopy analysis shows that these changes are attributed to variations of the coating porous structure during different treating times.

  20. The influence of alloy composition on residual stresses in heat treated aluminium alloys

    Robinson, J.S., E-mail: jeremy.robinson@ul.ie [Department of Mechanical, Aeronautical and Biomedical Engineering, University of Limerick (Ireland); Redington, W. [Materials and Surface Science Institute, University of Limerick (Ireland)

    2015-07-15

    The as quenched properties of eight different heat treatable aluminium alloys are related to residual stress magnitudes with the objective being to establish if there is a relationship between the residual stress and the as quenched alloy hardness and strength. Near surface residual stresses were assessed with X-ray diffraction using both the established sin{sup 2}ψ method and the more recent cos α technique. Through thickness residual stresses were also characterised using neutron diffraction. The alloys were chosen to encompass a wide range of strengths. The low to medium strength alloys were 6060 and 6082, medium to high strength 2618A, 2014A, 7075, 7010 and two variants of 7449, while the very high strength alloy was the powder metallurgy alloy N707. To assess the as quenched strength, dynamic hardness and tensile properties were determined from samples tested immediately after quenching to minimise the influence of precipitation hardening by natural aging. In addition, hot hardness measurements were made in situ on samples cooled to simulate quench paths. Within the experimental constraints of the investigation, the distribution of residual stress through the thickness was found to follow the same pattern for all the alloys investigated, varying from tensile in the interior to surface compression. The influence of alloy strength was manifested as a change in the observed residual stress magnitudes, and surface residual stresses were found to vary linearly with as quenched hardness and strength. - Highlights: • As quenched aluminium alloys contain high magnitude residual stresses. • Surface is compressive balance by a tensile core. • As quenched surface residual stress is linear function of alloy strength. • In situ hot hardness demonstrates rapid change in intrinsic hardness during rapid cooling.

  1. The influence of alloy composition on residual stresses in heat treated aluminium alloys

    The as quenched properties of eight different heat treatable aluminium alloys are related to residual stress magnitudes with the objective being to establish if there is a relationship between the residual stress and the as quenched alloy hardness and strength. Near surface residual stresses were assessed with X-ray diffraction using both the established sin2ψ method and the more recent cos α technique. Through thickness residual stresses were also characterised using neutron diffraction. The alloys were chosen to encompass a wide range of strengths. The low to medium strength alloys were 6060 and 6082, medium to high strength 2618A, 2014A, 7075, 7010 and two variants of 7449, while the very high strength alloy was the powder metallurgy alloy N707. To assess the as quenched strength, dynamic hardness and tensile properties were determined from samples tested immediately after quenching to minimise the influence of precipitation hardening by natural aging. In addition, hot hardness measurements were made in situ on samples cooled to simulate quench paths. Within the experimental constraints of the investigation, the distribution of residual stress through the thickness was found to follow the same pattern for all the alloys investigated, varying from tensile in the interior to surface compression. The influence of alloy strength was manifested as a change in the observed residual stress magnitudes, and surface residual stresses were found to vary linearly with as quenched hardness and strength. - Highlights: • As quenched aluminium alloys contain high magnitude residual stresses. • Surface is compressive balance by a tensile core. • As quenched surface residual stress is linear function of alloy strength. • In situ hot hardness demonstrates rapid change in intrinsic hardness during rapid cooling

  2. The role of magnesium in the electrochemical behaviour of 5XXX aluminium-magnesium alloys

    Flores Ramirez, J.R.

    2006-01-01

    An investigation concerning the effects of magnesium on the intergranular corrosion susceptibility of AA5XXX aluminium alloys was carried out. In the present work, magnesium is found to be highly mobile in the bulk metal as well as in the aluminium oxide. This mobility is also found to be dependent

  3. GAS-CREATION OF SEPARATING COVERINGS FOR MOULDS FOR DIE CASTING OF ALUMINIUM ALLOYS

    A. M. Mihaltsov; A. A. Pivovarchik; A. A. Subota

    2016-01-01

    The methods of experiments on determination of gascreating ability of different separating coverings for the moulds of aluminium alloys die casting are given and described in the article, and the results of investigation are given as well.

  4. The adsorption of an epoxy acrylate resin on aluminium alloy conversion coatings

    Grilli, R; Abel, ML; Baker, MA; Dunn, B.; Watts, JF

    2011-01-01

    A thermodynamic study of the adsorption of an epoxy acrylate resin used for UV-cured coatings on two different anticorrosion pretreatments on aluminium alloys relevant to aerospace industry has been undertaken. Aluminium alloy Al2219 specimens, treated with an inorganic chromate based conversion coating (Alodine 1200S) and an organic titanium based conversion coating (Nabutan STI/310), were immersed in solutions of different concentrations of the resin and adsorption isotherms were determined...

  5. Development and optimization of an AA2014 powder metallurgy aluminium alloy, characterization and corrosion behavior

    Redondo Ruiz, Enrique

    2014-01-01

    The light density of aluminium has make it one of the main materials used in the aeronautic and automotive industries. Both industries are constantly trying to reduce weight to save costs in combustibles. When heat treated, aluminium alloys obtain values of specific strength that allows them to compete with ferrous alloys. Powder metallurgy is an alternative to conventional manufacturing techniques, such as casting or forging. It can produce small pieces at high rate with a high complexity...

  6. Sol-gel derived nanocomposite materials for corrosion protection of aluminium alloys

    Schmidt, Helmut K.; Müller, Peter; Dittfurth, Carola; Albayrak, Sener; Puhl, Anne

    2000-01-01

    Thermally curable nanocomposite coating materials have been developed to seal and protect copper-containing aluminium alloys against corrosion. The coating material was prepared via the sol-gel-process starting from epoxy functionalised silanes, nanoscaled silica and organic diole crosslinker. This coating matrix was additionally supplied with a varying content of cerium oxide (1-20 wt.%). The corrosion protective efficiency of these coatings was investigated on aluminium alloys Al 6013-T6 an...

  7. Surface Chemistry of Aluminium Alloy Slid against Steel Lubricated by Organic Friction Modifier in Hydrocarbon Oil

    Ichiro Minami; Ayumi Sugibuchi

    2012-01-01

    The lubrication mechanism of aluminium alloy slid against steel was investigated from the standpoint of surface chemistry. Low friction and low wear were observed using glycerol mono-olate in a hydrocarbon as lubricant. Increase in the silicon content in the aluminium alloy during rubbing was observed by surface analyses using (1) Auger electron spectroscopy, (2) scanning electron microscopy along with energy dispersive X-ray spectroscopy, and (3) X-ray photoelectron spectroscopy. Mild remova...

  8. Microstructure Scaling Properties and Fatigue Resistance of Pre-Strained Aluminium Alloys (Part 1: Al-Cu alloy)

    Froustey, C.; NAIMARK, O.; BANNIKOV, M.; Oborin, V.

    2010-01-01

    Abstract The objective of this work is to provide the link between the fatigue behaviour of pre-strained aluminium alloys and the scaling properties of damage induced on the fracture surface. Fatigue tests performed on pre-strained aluminium alloys revealed a large difference in their residual fatigue resistance linked to the material: the Al-Cu alloy demonstrated a sharp decrease of HCF life-time due to the pre-straining whereas the insensitivity of the Al-Mg alloy was clear. For ...

  9. Surface mechanical behaviour of composite Ni-P-fly ash/zincate coated aluminium alloy

    Ni-P-fly ash coatings were produced on zincate coated 5083 wrought aluminium alloy substrates with the aid of an electroless deposition technique. Structural and chemical characterization of the produced coatings was performed with the aid of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron dispersive X-ray analysis (EDS) techniques. The Ni-P-fly ash coating was found to consist of an amorphous Ni-P matrix with dispersed fly ash particles. The wear resistance of the Ni-P-fly ash coating on zincate treated aluminium alloy was observed to be higher than that of the bare aluminium alloy, when sliding against a stainless steel counterface. In addition, the adhesion between the Ni-P-fly ash/zincate coating and the aluminium alloy substrate was also studied with a scratch testing apparatus. The adhesion strength of Ni-P-fly ash/zincate coating on the aluminium alloy substrate was observed to be higher in comparison to the Ni-P/zincate coating on the same aluminium alloy.

  10. Microscopic observation of pattern attack by aggressive ions on finished surface of aluminium alloy sacrificial anode

    This paper presents the results of a microscopic observation on submerged finished surface of aluminium alloy sacrificial anode. Experimental tests were carried out on polished surface aluminium anode exposed to seawater containing aggressive ions in order to observe of pattern corrosion attack on corroding surface of anode. Results have shown, at least under the present testing condition, that surface of sacrificial anode were attack by an aggressive ion such as chloride along grain boundaries. In addition, results of microanalysis showed that the corrosion products on surface of aluminium alloy have Al, Zn and O element for all sample and within the pit was consists of Al, Zn, O and Cl element. (author)

  11. Analysis of the influence oxygen and hydrogen during melting aluminium and his alloys

    A. W. Bydałek

    2011-07-01

    Full Text Available In the work was stated term the analysis of ion influences in melting codnuction of aluminium and his alloys. Influence from hydrogen and oxygen, hydrogen and oxygen and steam water together was distinguished. Where have worked out the scheme of influences leading to gas porosity of aluminium and his alloys. In analysis was referred to theory of double electric layer. It was conducted the analysis regularity of opinion influence oxygen and hydrogen in melt aluminium in support on Allena - Hewitta dependence.

  12. Corrosion Behaviour of Alpha Phase Aluminium Bronze Alloy in Selected Environments

    Oluwayomi BALOGUN; Joseph BORODE; Kenneth ALANEME; Michael BODUNRIN

    2014-01-01

    This research investigated the corrosion behaviour of aluminium (8 wt %) bronze alloys produced via sand casting in acidic, alkaline, and marine environments. The aluminium bronze was produced from aluminium (6063) alloy and copper scraps by sand casting according to European standard specification (UNS. C61400-CuAl8), after which they were cut into smaller sizes and immersed in the selected corrosive media for corrosion test investigation. H2SO4, NaCl, NaOH, and HCl of 0.1 M, 0.2 M, 0.3 M, 0...

  13. Scandium effect on corrosion resistance of aluminium and its alloys in 3% NaCl solution

    Scandium effect on corrosion and electrochemical features of aluminium and its high-impact alloys in NaCl 3%-solution is studied. Positive effect of scandium doping of alloys was determined. Mechanism of scandium behaviour when aluminium corrosion resistance is improved is suggested. The suggested mechanism takes account of scandium ability to be selectively dissolved and oxidized by water oxygen with formation of Sc2O3 oxide accumulated at the surface in the form of fine-dispersed precipitation insoluble in electrolyte and forming no mixed oxides with aluminium

  14. Effect of mechanical alloying and Ti addition on solution and ageing treatment of an AA7050 aluminium alloy

    Kátia Regina Cardoso; Dilermando Nagle Travessa; Asunción García Escorial; Marcela Lieblich

    2007-01-01

    In this work, solution heat treatments at different temperatures were performed in a commercial based AA7050 aluminium alloy, with and without titanium addition, produced by mechanical alloying and hot extrusion with the aim to investigate the effect of titanium addition and mechanical alloying in the precipitates stability. The same heat treatment conditions were used in a reference sample obtained from a commercial AA7050 alloy. Solution heat treated samples were characterised by differenti...

  15. Determination of ultratrace amounts of uranium and thorium in aluminium and aluminium alloys by electrothermal vaporization/ICP-MS

    A method has been developed for determining the 0.01 ng g-1 level of uranium and thorium in aluminium and aluminium alloys by electrothermal vaporization (ETV)/ICP-MS. This method was found to be significantly interfered with any matrices or other elements contained. An ion-exchange technique was therefore applied to separate uranium and thorium from aluminium and other elements. It was known that uranium are adsorbed on an anion-exchange resin and thorium are adsorbed on cation-exchange resin. However, aluminium and copper were eluted with 6 M hydrochloric acid. Dissolve the sample with hydrochloric acid containing copper which was added for analysis of pure aluminium, and oxidize with hydrogen peroxide. Concentration of hydrochloric acid in the solution was adjusted to 6 M, and then passed the solution through the mixed ion-exchange resin column. After the uranium and thorium were eluted with 1 M hydrofluoric acid-0.1 M hydrochloric acid, the solution was evaporated to dryness. It was then dissolved with 1 M hydrochloric acid. Uranium and thorium were analyzed by ETV/ICP-MS using tungsten and molybdenum boats, respectively, since the tungsten boat contained high-level thorium and the molybdenum boat contained uranium. The determination limit of uranium and thorium were 0.003 and 0.005 ng g-1, respectively. (author)

  16. Radiation effects in the aluminium alloys irradiated with neutrons

    Full text: Materials of fuel elements for water cooled nuclear reactors are exposed to simultaneous action of an ionizing radiation, temperature and yields of water radiolysis. In particular, irradiation by fast neutrons (En> 0.1 MeV) in research reactors influences mainly the mechanical properties of aluminium alloys, increasing their strength and reducing the plasticity. Radiation can essentially affect the stability of the heat-generating assembly material, changing its structure state. The structure change may also be the result of post-radiation ageing. This paper presents the results of studying the influence of reactor neutrons (research reactor of INP AS RU) on microstructure, electrical characteristics and length changes of SAV-1 and AMG-2 aluminium alloys used in nuclear industry. These alloys are low-alloyed solid solutions and intermetallic phases of CuAl2, Mg2Si, CuMgAl2, CuMg4Al6, Al2Mg2 in an equilibrium state. Samples were cut with orientation in 111 crystallographic axis in the shape of disks with the diameter d= 15 mm and thickness h= 3 mm for the metallographic analysis, and rods with the length of 40 mm and width d = 5 mm for measuring specific electrical resistance and linear dimension changes prior and after irradiations. For precise measurements the sample surfaces were mechanically handled and polished in a chemical solution, and then washed out in the distilled water and ethanol. Further samples, were put into the aluminum container and irradiated in a vertical channel of the reactor to fluencies 1018, 1019, 1020 n/cm2. The relative elongation (extension) δ was calculated as the measured length ratio of the non-irradiated and irradiated sample: δ=L0/L1x100%. Determination of element composition and the metallographic analysis of studied samples were done at the X-ray microanalyzer 'Jeol' JSM 5910 IV. Specific resistance (ρ) values were measures with four probe technique by compensation method at the direct voltage. The sample lengths

  17. Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content

    The present study embodies the results obtained with iron-aluminium alloys whose composition runs from 0 to nearly 50 atoms per cent aluminium. Conditions of elaboration and transformation have been studied successively, as well as the Young's modulus and the flow stress; the last chapter embodies, a study of the Portevin-le-Chatelier effect in alloys of 40 atoms per cent of aluminium. I) The principal difficulty to clear up consisted in the intergranular brittleness of ordered alloys; this brittleness has been considerably reduced with appropriate conditions of elaboration and transformation. II) The studies upon the Young's modulus are in connection with iron-aluminium alloys; transformation temperatures are well shown up. The formation of covalent bonds on and after 25 atoms per cent show the highest values of the modulus. III) The analysis of variations of the flow stress according to the temperature show some connection with ordered structures, the existence of antiphase domains and the existence of sur-structure dislocations. IV) In the ordered Fe Al domain the kinetics of the Portevin-le-Chatelier effect could be explained by a mechanism of diffusion of vacancies. The role they play has been specified by the influence they exert upon the dislocations; this has led us to the inhomogeneous Rudman order; this inhomogeneous order could explain the shape of the traction curves. (author)

  18. Residual stress measurements in laser clad aircraft aluminium alloys

    Fatigue and corrosion damage of structural components threatens the safety and availability of civil and military aircrafts. There is no sign of relief from these threats as civil and military aircrafts worldwide are continuously being pushed further into and past their initial design fatigue lives in tight financial circumstances. Given fatigue and corrosion damage often initiates at the surface and sub-surface of the components, there has been extensive research and development worldwide focused on advanced aircraft repair technologies and surface enhancement methods. The Deep Surface Rolling (DSR) is one of advanced surface enhancement technologies that can introduce deep compressive residual stresses into the surface of aircraft metallic structure to extend its fatigue life. For the development of cost-effective aircraft structural repair technologies such as laser cladding, in this study, aluminium alloy 7075-T651 specimens with simulated corrosion damage were repaired using laser cladding technology. The surface of the laser cladding region was then processed by DSR. The experimental results from subsequent fatigue testing of laser cladded baseline, DSR and post-heat treated laser cladded specimens discovered that the DSR process can significantly increase fatigue life in comparison with the ascladded baseline. The three dimensional residual stresses were measured by neutron diffraction and the results confirmed the beneficial compressive residual stresses at the cladding surface can be achieved in depth more than 1.0 mm.

  19. Mushy Zone Properties and Castability of Aluminium Foundry Alloys

    Dahle, A.K.

    1996-01-01

    The growing application and market share of aluminium castings demand better understanding of the mechanisms of defect formation during casting. Although casting is a cost-effective production route, inadequate reproducibility and quality of the cast structure often restrict the utilization of castings. This doctoral thesis aims to (1) determine how the solidification conditions affect the rheological behaviour in the partially solidified state, (2) to measure how alterations in solidification variables influence castability, and (3) to investigate the relationship between mushy zone rheology and castability. The development of mechanical strength in the mushy zone was measured as a function of chemical composition. Measurements of the dendrite coherency point provided accurate determination of the point where the dendrite network is established. The strength measurements confirm that the dendrites are largely independent and free-floating before dendrite coherency. The point and rate of strength development in the subsequently established interdendritic network strongly depend on the size and morphology of the dendrites and fraction solid. The castability investigation was limited to evaluations of fluidity and feeding. Fluidity measurements showed a complex effect of increased grain refinement. Alterations of the concentration and type of main alloying element gave a direct relationship between mushy zone rheology and fluidity. The range of the operating feeding mechanisms during solidification is directly related to the rheological properties of the mushy zone. 251 refs., 77 refs., 25 tabs.

  20. Comparison of modification with strontium and the refining with antimony in A 356 aluminium alloys

    Strontium and Antimony treated A356 aluminium alloy samples were metallographically characterized in the as cast and solution and aged conditions. Antimony treated alloy has shown slower spheroidizing kinetics of the Silicon particles during solution treatment, lower porosity level and higher tensile strength and elongation than Strontium treated one. (author)

  1. Gas accumulation at grain boundaries during 800 MeV proton irradiation of aluminium and aluminium-alloys

    Singh, Bachu Narain; Horsewell, Andy; Sommer, W. F.;

    1986-01-01

    Samples of pure aluminium (99.9999%) and commercial Al-2.7%Mg(AlMg3) and Al-1.1%Mg-0.5%Si(Al6061) alloys were irradiated with 800 MeV protons at the Los Alamos Meson Physics Facility (LAMPF) at a temperature between 40-100°C to a maximum dose of 0.2 dpa. Transmission electron microscopy (TEM) sho...... higher than in the pure Al. The amount of gas accumulation at grain boundaries was found to depend on gas generation rate, alloying and cold-work microstructure...

  2. Effect of Alloying Elements to Aluminium on the Wettability of AL/SiC System

    CANDAN, Ercan

    2002-01-01

    The wettability at a liquid Al-alloy/SiC interface was evaluated by the sessile drop method at 750oC. The wetting angle, q ,of a sessile drop on SiC substrate decreased with the addition of Pb, Mg and Ca to pure aluminium. The reduction in q of the Al-Pb alloy was proportional to the reduction in surface tension, glv, of aluminium, whereas in Al-Mg and Al-Ca alloys the reduction in q was greater than the reduction in g lv of Al. This was attributed to reactions that took place at the Al-all...

  3. BEHAVIOUR OF COPPER AND ALUMINIUM ELECTRODES ON EDM OF EN-8 ALLOY STEEL

    DHANANJAY PRADHAN; Dr. S. C. JAYSWAL

    2011-01-01

    Electrical discharge machining (EDM) has been recognized as an efficient production method for precision machining of electrically conducting hardened materials. Copper and aluminium are used as electrode materials in this process with Kerosene oil as the dielectric medium. In this work, the behavior of copper and aluminium electrodes on electric discharge machining of EN-8 alloy steel had been studied. Keeping all other machining parameters same, the hardened work material was machined with ...

  4. Tribological Behaviour of W-DLC against an Aluminium Alloy Subjected to Lubricated Sliding

    S. Bhowmick; A. Banerji; A.T. Alpas

    2015-01-01

    Diamond like carbon (DLC) coatings mitigate aluminium adhesion and reduce friction under the ambient conditions but their tribological behaviour under lubricated sliding need to be further investigated. In this study, tribological tests were performed to evaluate the friction and wear characteristics of W-DLC and H-DLC coatings sliding against an aluminium alloy (319 Al) under unlubricated (40 % RH) and lubricated sliding conditions. For unlubricated sliding, coefficient of friction (COF) val...

  5. Effect of Slow Cooling in Reducing Pore Size in a Sintered Powder Metallurgical 6061Aluminium Alloy

    S. Solay Anand; B.Mohan; T. R. Parthasarathy

    2011-01-01

    The usage of powder metallurgy aluminium compacts in lieu of ferrous components in automotives helps to lower vehicle weight. The major drawback in the commercially available press sintered aluminium alloy is porosity which is mainly dependent on the powder metallurgical process parameters such as compaction pressure, sintering temperature and cooling rate after sintering. In this paper the effect of particle size and furnace controlled cooling after sintering on porosity level and micro hard...

  6. Additive manufacture of an aluminium alloy: processing, microstructure, and mechanical properties

    Aboulkhair, Nesma T.

    2016-01-01

    Additive manufacturing of aluminium alloys using selective laser melting (SLM) is of research interest nowadays because of its potential benefits in industry sectors such as aerospace and automotive. However, in order to demonstrate the credibility of aluminium SLM for industrial needs, a comprehensive understanding of the interrelation between the process parameters, produced microstructure, and mechanical behaviour is still needed. This thesis aims at contributing to developing this compreh...

  7. Interaction of lead-borate glass with aluminium and iron-nickel alloys

    Interaction of aluminium (AMG-6) and iron-nickel (47ND) alloys with lead-borate glass of PbO-73, BeO3-12, ZnO-10, Al2O3-3, SiO2-2 (mas. %) composition is investigated. It is determined that components of both soldered alloys interact actively with lead-borate glass melt that allows to obtain strong cohesion of glass with AMG-6 and 47ND metal alloys

  8. Recycling of Glass Fibre Reinforced Aluminium Laminates and Silicon Removal from Aerospace Al Alloy

    Zhu, G

    2012-01-01

    Aerospace aluminium alloys (7xxx and 2xxx series Al alloy) is one of the important Al alloys in our life. The recycling of aerospace Al alloy plays a significant role in sustainable development of Al industry. The fibre reinforced metal laminates GLARE including 67 wt.% 2024 Al alloy was used as upper fuselage in Airbus A380, but the solution for GLARE recycling is not available. Thermal recycling which uses high temperature to decompose the resin and separate the reinforcement fibres and fil...

  9. HIGH PURITY ALUMINIUM-LITHIUM MASTER ALLOY BY MOLTEN SALT ELECTROLYSIS

    Watanabe, Y.; Toyoshima, M.; Itoh, K.

    1987-01-01

    The aim of this work is to develop the economical production process of the Al-Li master alloy free from metallic sodium, calcium and potassium. This master alloy can be used for aluminium-lithium alloys for structual materials of aircrafts, automobiles and robots. Moreover the Al-Li master alloy with lithium content of 18-20wt. % is applicable to the blanket of fusion reactors and the active mass of batteries. This Al-Li master alloy can be produced by means of LiCl-KCl molten salt electroly...

  10. Process parameters optimization for friction stir welding of RDE-40 aluminium alloy using Taguchi technique

    A.K.LAKSHMINARAYANAN; V.BALASUBRAMANIAN

    2008-01-01

    Taguchi approach was applied to determine the most influential control factors which will yield better tensile strength of the joints of friction stir welded RDE-40 aluminium alloy. In order to evaluate the effect of process parameters such as tool rotational speed, traverse speed and axial force on tensile strength of friction stir welded RDE-40 aluminium alloy, Taguchi parametric design and optimization approach was used. Through the Taguchi parametric design approach, the optimum levels of process parameters were determined. The results indicate that the rotational speed, welding speed and axial force are the significant parameters in deciding the tensile strength of the joint. The predicted optimal value of tensile strength of friction stir welded RDE-40 aluminium alloy is 303 MPa. The results were confirmed by further experiments.

  11. The research of corrosion defects in aluminium alloy SAV-1, irradiated by neutrons

    The study of corrosion resistance of rod from low aluminium alloy SAV-1 after a long term operating in the nuclear reactor WWR-K and in water pool storage are resulted. The corrosion tests executed with usage of chemical and electrochemical methods of an estimation of a fixed potential and corrosion rate in chlorine solution to the environment on an accelerated mode on samples cut from the top and bottom end of a atomic reactor rod. With application of methods of a volume determination by hydrostatic weighting of corrosion of aluminium alloy SAV-1 irradiated by a different fluency of neutrons. Is showing, that the irradiation decrease periods of passivation and accelerates a rate corrosion of aluminium alloy SAV-1. (author)

  12. Image analysis of atmospheric corrosion of field exposure high strength aluminium alloys

    Tao, Lei; Song, Shizhe; Zhang, Xiaoyun; Zhang, Zheng; Lu, Feng

    2008-08-01

    The corrosion morphology image acquisition system which can be used in the field was established. In Beijing atmospheric corrosion exposure station, the image acquisition system was used to capture the early stage corrosion morphology of five types of high strength aluminium alloy specimens. After the denoise treatment, wavelet-based image analysis method was applied to decompose the improved images and energies of sub-images were extracted as character information. Based on the variation of image energy values, the corrosion degree of aluminium alloy specimens was qualitatively and quantitatively analyzed. The conclusion was basically identical with the result based on the corrosion weight loss. This method is supposed to be effective to analysis and quantify the corrosion damage from image of field exposure aluminium alloy specimens.

  13. Determination of lithium in lithium-aluminium alloy by capillary electrophoresis

    A simple and rapid method for the determination of lithium in lithium-aluminium alloy using capillary electrophoresis (CE) is developed. The method separates Li from other metal ions and it does not require prior separation of aluminium, which is major constituent of the alloy. Separation of Li was achieved using BGE of 20mM Imidazole (pH 2) with an applied voltage of 20kV. The precision of the method is better than 10% at 0.5 ppm of Li and LOD is 0.12 ppm. (author)

  14. Adherence of electrodeposited Zn-Ni coatings on EN AW2024 T3 aluminium alloy

    Alexis, Joël; Adrian, Denise; Masri, Talal; Petit, Jacques-Alain

    2004-01-01

    The use of hexavalent chromium in surface treatments will be reduced in the future, as it is suspected to be carcinogenic. Electrodeposition of Zn-Ni, which is currently used on steel, represents a non-chromate alternative surface treatment for the corrosion protection of aluminium alloys. Zn-Ni coatings were electrodeposited onto an EN AW2024 T3 aluminium alloy sheet in a laboratory flow cell. To obtain several percentages of Ni in the coatings, solutions with different Ni2+ concentrations w...

  15. Integrated Precipitate Simulation for Friction Stir Welding of Age Hardening Aluminium Alloys

    Hersent, Emmanuel

    2010-01-01

    Friction stir welding (FSW) is a recent welding process invented by The Welding Institute (TWI). It is particularly interesting for the aeronautical sector due to its capacity to weld 2XXX and 7XXX age-hardening aluminium alloys, which were previously considered unweldable. This relatively new process is currently the subject of active research. This work aims to simulate the hardness profile of an AA2024-T3 friction stir weld. AA2024-T3 is an age hardening aluminium alloy, so it is necessary...

  16. Predicting the thermal conductivity of aluminium alloys in the cryogenic to room temperature range

    Woodcraft, Adam L.

    2005-06-01

    Aluminium alloys are being used increasingly in cryogenic systems. However, cryogenic thermal conductivity measurements have been made on only a few of the many types in general use. This paper describes a method of predicting the thermal conductivity of any aluminium alloy between the superconducting transition temperature (approximately 1 K) and room temperature, based on a measurement of the thermal conductivity or electrical resistivity at a single temperature. Where predictions are based on low temperature measurements (approximately 4 K and below), the accuracy is generally better than 10%. Useful predictions can also be made from room temperature measurements for most alloys, but with reduced accuracy. This method permits aluminium alloys to be used in situations where the thermal conductivity is important without having to make (or find) direct measurements over the entire temperature range of interest. There is therefore greater scope to choose alloys based on mechanical properties and availability, rather than on whether cryogenic thermal conductivity measurements have been made. Recommended thermal conductivity values are presented for aluminium 6082 (based on a new measurement), and for 1000 series, and types 2014, 2024, 2219, 3003, 5052, 5083, 5086, 5154, 6061, 6063, 6082, 7039 and 7075 (based on low temperature measurements in the literature).

  17. Recent developments of the aluminium-lithium system alloys for aircraft uses

    A brief review is made of the latest developments in the production of Aluminium-Lithium alloys. The necessity for new materials in the field of aeronautics has speeded up research on metallic and non-metallic materials. Lately, a good part of the research in the field of metallic components has been directed at Al-Li alloys. More recently, with the development of quaternary alloys Al-Li-X-X, the old problem of low toughness was overcome. The finality of this study is to cover the developments of the mentioned alloys, including the fundamentals of physical metallurgy of the complex system recently developed Al-Li-Cu-Mg. (author)

  18. MICROSTRUCTURAL AND MECHANICAL STUDY OF ALUMINIUM ALLOYS SUBMITTED TO DISTINCT SOAKING TIMES DURING SOLUTION HEAT TREATMENT

    Valmir Martins Monteiro

    2014-12-01

    Full Text Available This work studies the microstructural characteristics and mechanical properties for different aluminium alloys (1100, 3104 and 8011 hot rolled sheets that were subjected to a solution heat treatment with distinct soaking times, in order to promote microstructural and mechanical changes on these alloys with solute fractions slightly above the maximum solubility limit. Scanning Electronic Microscopy (SEM / Energy Dispersive Spectroscopy X-Ray (EDS, X-Ray Diffraction (XRD and Hardness Tests were employed to observe the microstructural / compositional and mechanical evaluation. For the 1100 and 8011 alloys the more suitable soaking time occur between 1 and 2 hours, and for the 3104 alloy occurs between 2 and 3 hours.

  19. Structure and selected properties of high-aluminium Zn alloy with silicon addition

    A. Zyska; Z. Konopka; M. Łągiewka; M. Nadolski

    2011-01-01

    The results of examinations concerning the abrasive wear resistance, hardness, and thermal expansion of high-aluminium zinc alloys are presented. The examinations were carried out for five synthetic ZnAl28 alloys with variable silicon content ranging from 0.5% to 3.5%, and – for the purpose of comparison – for the standardised ZnAl28Cu4 alloy. It was found that silicon efficiently increases the tribological properties and decreases the coefficient of thermal expansion of zinc alloys. The most...

  20. Evaluation of the mechanical properties of microarc oxidation coatings and 2024 aluminium alloy substrate

    Xue Wen Bin; Deng Zhi Wei; Chen Ru Yi; Li Yong Liang; Zhang Ton Ghe

    2002-01-01

    A determination of the phase constituents of ceramic coatings produced on Al-Cu-Mg alloy by microarc discharge in alkaline solution was performed using x-ray diffraction. The profiles of the hardness, H, and elastic modulus, E, across the ceramic coating were determined by means of nanoindentation. In addition, a study of the influence of microarc oxidation coatings on the tensile properties of the aluminium alloy was also carried out. The results show that the H-and E-profiles are similar, and both of them exhibit a maximum value at the same depth of coating. The distribution of the alpha-Al sub 2 O sub 3 phase content determines the H- and E-profiles of the coatings. The tensile properties of 2024 aluminium alloy show less change after the alloy has undergone microarc discharge surface treatment.

  1. Evaluation of the mechanical properties of microarc oxidation coatings and 2024 aluminium alloy substrate

    Xue Wenbin [Key Laboratory for Radiation Beam Technology and Materials Modification, Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing, 100875 (China); Wang Chao [Key Laboratory for Radiation Beam Technology and Materials Modification, Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing, 100875 (China); Deng Zhiwei [Key Laboratory for Radiation Beam Technology and Materials Modification, Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing, 100875 (China); Chen Ruyi [Key Laboratory for Radiation Beam Technology and Materials Modification, Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing, 100875 (China); Li Yongliang [Analytical and Testing Centre, Beijing Normal University, Beijing, 100875 (China); Zhang Tonghe [Key Laboratory for Radiation Beam Technology and Materials Modification, Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing, 100875 (China)

    2002-11-11

    A determination of the phase constituents of ceramic coatings produced on Al-Cu-Mg alloy by microarc discharge in alkaline solution was performed using x-ray diffraction. The profiles of the hardness, H, and elastic modulus, E, across the ceramic coating were determined by means of nanoindentation. In addition, a study of the influence of microarc oxidation coatings on the tensile properties of the aluminium alloy was also carried out. The results show that the H-and E-profiles are similar, and both of them exhibit a maximum value at the same depth of coating. The distribution of the {alpha}-Al{sub 2}O{sub 3} phase content determines the H- and E-profiles of the coatings. The tensile properties of 2024 aluminium alloy show less change after the alloy has undergone microarc discharge surface treatment.

  2. Recovery of actinides from actinide–aluminium alloys by chlorination: Part II

    Souček, P., E-mail: pavel.soucek@ec.europa.eu [European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany); Cassayre, L. [Laboratoire de Génie Chimique (LGC), Département Procédés Electrochimiques, CNRS-UMR 5503, Université de Toulouse III – Paul Sabatier, 31062 Toulouse Cedex 9 (France); Eloirdi, R.; Malmbeck, R.; Meier, R.; Nourry, C.; Claux, B.; Glatz, J.-P. [European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany)

    2014-04-01

    A chlorination route is being investigated for recovery of actinides from actinide–aluminium alloys, which originate from pyrochemical recovery of actinides from spent metallic nuclear fuel by electrochemical methods in molten LiCl–KCl. In the present work, the most important steps of this route were experimentally tested using U–Pu–Al alloy prepared by electrodeposition of U and Pu on solid aluminium plate electrodes. The investigated processes were vacuum distillation for removal of the salt adhered on the electrode, chlorination of the alloy by chlorine gas and sublimation of the AlCl{sub 3} formed. The processes parameters were set on the base of a previous thermochemical study and an experimental work using pure UAl{sub 3} alloy. The present experimental results indicated high efficiency of salt distillation and chlorination steps, while the sublimation step should be further optimised.

  3. Modelling the corrosion behaviour of Al2CuMg coarse particles in copper-rich aluminium alloys

    Blanc, Christine; Freulon, Alexandre; Lafont, Marie-Christine; Kihn, Yolande; Mankowski, Georges

    2006-01-01

    The corrosion behaviour of 2024 aluminium alloy in sulphate solutions was studied; attention was focused on the influence of coarse intermetallic Al2CuMg particles on the corrosion resistance of the alloy. Model alloys representative of the aluminium matrix and of Al2CuMg coarse intermetallics were synthesized by magnetron sputtering. Open-circuit potential measurements, current–potential curve plotting and galvanic coupling tests were performed in sulphate solutions with or without chlorides...

  4. Emeraldine base as corrosion protective layer on aluminium alloy AA5182, effect of the surface microstructure

    Cecchetto, L; Ambat, Rajan; Davenport, A.J.;

    2007-01-01

    AA5182 aluminium alloy cold rolled samples were coated by thin Wlms of emeraldine base (EB) obtained from a 5% solution in N-methylpyrrolidinone. Accelerated corrosion tests prove this coating very eVective for corrosion protection of aluminium alloys in neutral environment. This study underlines...... the prominent role of surface cathodic intermetallic particles in pit initiation and coating break down in enhanced corrosion conditions and suggest that, beside the EB barrier properties, the enhanced corrosion resistance observed on the EB coated samples could partly arise from two other mains...... factors: • a weak redox activity of the polymer which passivate the metal, • a proton involving self-healing process taking place at the polymer–metal interface, which contributes to delay local acidiWcation in Wrst steps of corrosion on EB coated aluminium surfaces....

  5. High Pressure Die Casting of Aluminium and Magnesium Alloys : Grain Structure and Segregation Characteristics

    Laukli, Hans Ivar

    2004-01-01

    Cold chamber high pressure die casting, (HPDC), is an important commercial process for the production of complex near net shape aluminium and magnesium alloy castings. The work presented in the thesis was aimed at investigating the microstructure formation in this type of casting. The solidification characteristics related to the process and the alloys control the formation of grains and defects. This again has a significant impact on the mechanical properties of the castings.The investigatio...

  6. Arc welding of high strength aluminium alloys for armour systems applications

    Pickin, Craig Graeme

    2011-01-01

    The ternary Al-Cu-Mg system 2xxx series aluminium alloys were examined as construction materials for armour system applications based upon comparable ballistic properties to the currently employed Al-7xxx series alloys. Utilising MIG welding solidification cracking was evident when welding constrained Al-2024 candidate base material using Al-2319 filler, the only available consumable wire for this series. A previously developed thermodynamic model suggested that an incompatible...

  7. Corrosion Control of Friction Stir Welded AA2024-T351 Aluminium Alloys

    Younes, Yousif Younes Abo

    2010-01-01

    Friction stir welding (FSW) is a modern solid state welding technique developed at thewelding institute (TWI) in 1991. The joining is achieved by heat generation, materialsoftening and plastic deformation following the travelling of non-consumable pin throughthe gap between the two workpieces to be joined.In present study, joining of AA 2024-T3 aluminium alloy, is achieved by FSW. Theinfluence of the FSW on the alloy microstructure and corrosion behaviour is determined.The effect of laser sur...

  8. THE EFFECT OF THE ALUMINIUM ALLOY SURFACE ROUGHNESS ON THE RESTITUTION COEFFICIENT

    Stanisław Bławucki; Kazimierz Zaleski

    2015-01-01

    The paper presents the results of research on the effect of the surface roughness of aluminum alloy on its coefficient of restitution. It describes the current method of finishing the workpiece surface layer after cutting and innovative measuring device which was used in the research. The material used in the research was aluminium alloy EN AW 7075. The paper also presents a relationship between the coefficient of restitution and surface roughness of the milled samples as well as impressions ...

  9. Identification of the metallurgical parameters explaining the corrosion susceptibility in a 2050 aluminium alloy

    Guérin, Mathilde; Alexis, Joël; Andrieu, Eric; Laffont-Dantras, Lydia; Lefebvre, Williams; Odemer, Grégory; Blanc, Christine

    2016-01-01

    The corrosion behaviour of a 2050 aluminium alloy was studied in a NaCl solution. The structure ofprecipitation did not fully explain the susceptibility to intergranular (in the -T34 state) and intragran-ular corrosion for the aged state (the -T8 state). A relationship between the nature of interfaces, thegrains characteristics (size, internal misorientation and orientation according to the plane exposed tothe electrolyte) on one hand and the corrosion susceptibility of the alloy on the other...

  10. Aluminium Alloy-Based Metal Matrix Composites: A Potential Material for Wear Resistant Applications

    Rupa Dasgupta

    2012-01-01

    Aluminium alloy-based metal matrix composites (AMMCs) have been by now established themselves as a suitable wear resistant material especially for sliding wear applications. However, in actual practice engineering components usually encounter combination of wear types. An attempt has been made in the present paper to highlight the effect of dispersing SiC in 2014 base alloy adopting the liquid metallurgy route on different wear modes like sliding, abrasion, erosion, and combinations of wear m...

  11. Influence of modification on structure, fluidity and strength of 226D aluminium alloy

    A. Dolata-Grosz; M. Dyzia; J. Śleziona

    2008-01-01

    In the article the fluidity, solidification conditions, microstructure and tensile properties have been studied for the non-modified and modified 226D aluminium silicon alloy.Realized investigations concerned modification of alloy 226D for application as the matrix to carbon fibre reinforcement composite (MMC-Cf). One of main factors determining to good connection between metal matrix and fibres reinforcement is good wettability. It is possible to obtain suitable conditions of wettability by ...

  12. Use of acoustic energy in the processing of molten aluminium alloys

    Puga, Hélder; Barbosa, J; Costa, Sónia; Ribeiro, Carlos Silva

    2013-01-01

    During the last years aluminium alloys have been gaining increased acceptance as structural materials in the automotive and aeronautical industries, mainly due to their light weight, good formability and corrosion resistance. However, improvement of mechanical properties is a constant in research activities, either by the development of new alloys or by microstructure manipulation. This presentation focuses a novel effective dynamic methodology to perform microstructural refinement / modi...

  13. Latest investigations for determination of oxygen content in aluminium and its alloys

    Thin layer on the surface of metal prevents to determine oxygen content in the high purity aluminium and in its alloys. Experiments and their results have been presented, directed towards elimination of errors appearing due to the surface oxides during activation analysis by means of a neutron generator application

  14. The Interaction between Particles and Low Angle Boundaries during Recovering of Aluminium-Alumina Alloys

    Jones, A.R.; Hansen, Niels

    1981-01-01

    Certain quantitative and qualitative aspects both of subgrain growth and of the interaction between particles and low angle grain boundaries during recovery have been investigated in two aluminium alloys containing low volume fractions of small alumina particles. Quantitative data have been...

  15. Small fatigue crack growth in aluminium alloy EN-AW 6082/T6

    Jíša, D.; Liškutín, P.; Kruml, Tomáš; Polák, Jaroslav

    2010-01-01

    Roč. 32, č. 12 (2010), s. 1913-1920. ISSN 0142-1123 R&D Projects: GA ČR GA101/07/1500 Institutional research plan: CEZ:AV0Z20410507 Keywords : Aluminium alloy s * small cracks * grack growth rate Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.799, year: 2010

  16. Influência do superaquecimento nas variáveis térmicas de solidificação e na formação da microestrutura de ligas de alumínio Overheating influence on solidification - thermal variables and microstructure formation of aluminium alloy

    Jean Robert Pereira Rodrigues

    2009-12-01

    Full Text Available O objetivo do trabalho é o desenvolvimento de uma análise comparativa do processo de solidificação da liga de alumínio com diferentes taxas de superaquecimento. Os principais parâmetros de solidificação foram determinados experimentalmente afetados pelo grau de superaquecimento e sua influência na formação da microestrutura. Foi escolhida a liga de AA5052 contendo 3% de magnésio pelo seu interesse comercial. A liga foi vazada com três diferentes graus de superaquecimento, em um dispositivo que permite a solidificação unidirecional e o monitoramento, através de um sistema de aquisição de dados, das variações de temperatura em diferentes posições da peça. A partir dos resultados de temperatura são determinados outros parâmetros do processo. Os espaçamentos interdendríticos são determinados a partir das micrografias. Através da análise experimental, é determinada a influência do grau de superaquecimento nos seguintes parâmetros relativos ao processo de solidificação: coeficiente de transferência de calor na interface metal/molde, velocidade de avanço da frente de solidificação, gradiente de temperatura em frente à isoterma liquidus, taxa de resfriamento, tempo local de solidificação e espaçamentos interdendríticos primário e secundário. Também é analisada a transição entre a estrutura colunar e equiaxial.A comparative analysis of the 5052 aluminum alloy solidification process involving different overheating ranges is presented herein. Experimentally determined, the main parametersof the solidification process were affected in the overheating range and influenced the microstructure arrangement. The 5052 aluminium alloy was selected.It contains about 3% magnesium and is used for commercial purposes. The aluminium alloy was poured into a device that allows unidirectional solidification and was programmed with three different overheating ranges. Temperature variation at different sample positions was

  17. Study of localized corrosion in AA2024 aluminium alloy using electron tomography

    Highlights: ► SEM tomography of localized corrosion has been achieved. ► Nanotomography provides evidence that links microstructure and corrosion propagation path. ► IGC stemmed from localized corrosion associated with buried clusters of intermetallics. ► IGC started beneath the alloy surface and may emerge on the alloy surface. - Abstract: SEM based tomography of localized corrosion has been achieved using selective detection of backscattered electrons. The high resolution tomography provides direct evidence that links the surface appearance of corroded alloy, the alloy microstructure and the corrosion propagation path. Stable localized corrosion of AA2024-T351 aluminium alloy was initiated at locations where large clusters of S phase particles were buried beneath the surface. Propagating away from the initiation sites, corrosion developed preferentially along the grain boundary network. The grain boundary attack started beneath the alloy surface, proceeded along preferred grain boundaries and may emerge at the alloy surface.

  18. Aging of maraging steel welds during aluminium alloy die casting

    Klobčar, Damjan; Pleterski, Matej; Taljat, Boštjan; Kosec, Ladislav; Tušek, Janez

    2015-01-01

    The aim of this study is to evaluate precipitation annealing of 18% Ni maraging steel repair welds during aluminium die casting and to predict the prolonged in-service tool life. The emphasis of this study is the influence ofpost-weld precipitation annealing heat treatment and aluminium die casting thermal cycling on metallurgical and mechanical properties. A series of specimens of 1.2344 tool steel is prepared to which 1.6356 maraging steel is GTA weld cladded. Analysis of weld microstructur...

  19. Oxidation behavior of FeCr and FeCrY alloys coated with an aluminium based paint

    Marina Fuser Pillis; Olandir Vercino Correa; Edval Gonçalves de Araújo; Lalgudi Venkataraman Ramanathan

    2008-01-01

    A variety of metallic components rely on properties that are specific to the alloy and its surface. Coatings have been extensively used to protect metallic surfaces from the aggressive effects of the environment to which it is exposed. In this investigation, the high temperature oxidation behavior of a FeCr and a FeCrY alloy coated with an aluminium based paint has been studied. The objective was to form the more resistant alumina surface layer on an aluminium free alloy. Aluminium based pain...

  20. Aluminium enriched diffusion layers on NiAl alloy

    Bartuška, Pavel; Lašek, Jiří; Paidar, Václav

    2003-01-01

    Roč. 19, č. 3 (2003), s. 185-188. ISSN 0267-0844 R&D Projects: GA AV ČR IAA1041302 Institutional research plan: CEZ:AV0Z1010914 Keywords : intermetallics based on Ni-Al * aluminium enriched diffusion layers * local elemental analysis Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.571, year: 2003

  1. The effect of nickel on alloy microstructure and electrochemical behaviour of AA1050 aluminium alloy in acid and alkaline solutions

    The study investigates the influence of nickel and magnesium additions to AA1050 aluminium alloy on the alloy electrochemical behaviour in sodium hydroxide and hydrochloric solutions under conditions relevant to industries that use alkaline etching as a standard surface treatment procedure and to the lithographic and electronic industries where surface convolution is assisted by pitting in hydrochloric acid. Scanning and transmission electron microscopes were used to characterize the intermetallic particles, and scanning Kelvin probe microscopy was utilised in monitoring the surface potential. Nickel is shown to be incorporated into second phase particles, which mostly consisted of Al3Fe and α-(AlFeSi) phases, resulting in enhanced cathodic activity on the aluminium surface. Consequently, the dissolution rates of the superpure aluminium, alloys without nickel addition and alloy with nickel addition are increased respectively in sodium hydroxide, and increased pitting is respectively promoted in hydrochloric acid. In contrast, the addition of magnesium to the alloy had negligible influence on the etching and pitting behaviour.

  2. Steam assisted oxide growth on aluminium alloys using oxidative chemistries: Part II corrosion performance

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    Surface treatment of aluminium alloys using steam with oxidative chemistries, namely KMnO4 and HNO3 resulted in accelerated growth of oxide on aluminium alloys. Detailed investigation of the corrosion performance of the treated surfaces was carried out using potentiodynamic polarisation and...... standard industrial test methods such as acetic acid salt spray (AASS) and filiform corrosion on commercial AA6060 alloy. Barrier properties of the film including adhesion were evaluated using tape test under wet and dry conditions. Electrochemical results showed reduced cathodic and anodic activity, while...... the protection provided by steam treatment with HNO3was a function of the concentration of NO3−ions. The coating generated by inclusion of KMnO4showed highest resistance to filiform corrosion. Overall, the performance of the steam treated surfaces under filiform corrosion and AASS test was a result of...

  3. The influence of alloying elements in aluminium on the grain refinement with ALTI5B1

    Naglič I.

    2009-07-01

    Full Text Available This work deals with the influence of alloying elements in aluminium on the grain refinement with various additions of AlTi5B1. Grain-refinement tests were made at a cooling rate of 15 °C/s. The results revealed that in both aluminium and an Al-Fe alloy the grain size decreases with increasing additions of the AlTi5B1 grain refiner. We found that for the same boron content the grain size was smaller in the case of the Al-Fe alloy. The difference in the grain sizes for the same content of boron was approximately 15 μm; this is considerably smaller than the difference between the grain sizes in samples with the same difference of growth-restricting factor made at slower cooling rates.

  4. Characterization of steam generated anti-corrosive oxide films on Aluminium alloys

    Din, Rameez Ud; Jellesen, Morten Stendahl; Ambat, Rajan

    2014-01-01

    hexavalent chromium is strictly regulated due to its toxic nature and suspected carcinogenicity. So, it is highly imperative to develop other alternatives for chrome conversion coatings. Treatment of aluminium with natural water at elevated temperatures results in the formation of different forms of...... converted or transformed into functional conversion coatings in order to enhance corrosion resistance and adhesion to paint systems. Chromium based conversion coatings have been extensively used on aluminium alloys to improve adhesion of subsequent paint layers and corrosion resistance. However, the use of...

  5. Semi-Solid Processing by Electric Current During Sand Casting of Aluminium Alloys

    Prodhan, Anjan

    2016-02-01

    This study reports the effect of DC and 50Hz AC treatment (ECT) on aluminium or aluminium alloys during solidification in sand moulds i.e., at their semisolid state. Castings, with different geometry, were made in open or closed sand moulds. It is observed that ECT (a) reduces dissolved gas, (b) reduces internal shrinkage and (c) metal mould reactions in castings. It is also observed that the AC treatment is more effective compared to DC treatment. ECT changes the movement of solidification front. The optical microstructures of ECT samples are quite similar to the samples treated in other semisolid processing methods.

  6. Abrasive wear response of aluminium alloy-sillimanite particle reinforced composite under low stress condition

    Singh, M. [Regional Research Laboratory (CSIR), Hoshangabad Road, Near Habibganj Naka, Bhopal 462 026 (India)]. E-mail: mulayam_singh@hotmail.com; Mondal, D.P. [Regional Research Laboratory (CSIR), Hoshangabad Road, Near Habibganj Naka, Bhopal 462 026 (India); Das, S. [Regional Research Laboratory (CSIR), Hoshangabad Road, Near Habibganj Naka, Bhopal 462 026 (India)

    2006-03-15

    The abrasive wear behaviour of aluminium alloy-sillimanite particle reinforced composite under low stress condition has been reported and the results have been compared with the corresponding matrix alloy which was produced and cast under similar conditions. The study showed that wear resistance (inverse of wear rate) of the composite was higher than the matrix alloy. The wear rate decreased with sliding distance and increased with applied load irrespective of materials. The worn surfaces and subsurfaces of the tested samples were examined in the scanning electron microscope in order to understand the material removal mechanism during low stress abrasive wear process.

  7. Application of artificial neural networks for modelling correlations in age hardenable aluminium alloys

    F. Musharavati

    2010-07-01

    Full Text Available Purpose: This paper discusses some of the preliminary results of an ongoing research on the applications of artificial neural networks (ANNs in modelling, predicting and simulating correlations between mechanical properties of age hardenable aluminium alloys as a function of alloy composition.Design/methodology/approach: Appropriate combinations of inputs and outputs were selected for neural network modelling. Multilayer feedforward networks were created and trained using datasets from public literature. Influences of alloying elements, alloy composition and processing parameters on mechanical properties of aluminium alloys were predicted and simulated using ANNs models.Two sample t-tests were used to analyze the prediction accuracy of the trained ANNs.Findings: Good performances of the neural network models were achieved. The models were able to predict mechanical properties within acceptable margins of error and were able to provide relevant simulated data for correlating alloy composition and processing parameters with mechanical properties. Therefore, ANNs models are convenient and powerful tools that can provide useful information which can be used to identify desired properties in new aluminium alloys for practical applications in new and/or improved aluminium products.Research limitations/implications: Few public data bases are available for modelling properties. Minor contradictions on the experimental values of properties and alloy compositions were also observed. Future work will include further development of simulated data into property charts.Practical implications: Correlations between mechanical properties and alloy compositions can help in identifying a suitable alloy for a new or improved aluminum product application. In addition, availability of simulated structure-process-property data or charts assists in reducing the time and costs of trial and error experimental approaches by providing near-optimal values that can be used

  8. BEHAVIOUR OF COPPER AND ALUMINIUM ELECTRODES ON EDM OF EN-8 ALLOY STEEL

    DHANANJAY PRADHAN

    2011-07-01

    Full Text Available Electrical discharge machining (EDM has been recognized as an efficient production method for precision machining of electrically conducting hardened materials. Copper and aluminium are used as electrode materials in this process with Kerosene oil as the dielectric medium. In this work, the behavior of copper and aluminium electrodes on electric discharge machining of EN-8 alloy steel had been studied. Keeping all other machining parameters same, the hardened work material was machined with the two electrodes at different values of peak current, pulse-on time & duty factor according to 23 full factorial design. It has been found that copper shows better results than aluminium in term of surface finish (μm in same dielectric media. Therefore, copper is recommended as a good electrode material.

  9. Microstructure and interfaces of a reaction coating on aluminium alloys by laser processing

    This paper reports an approach to coat a ceramic layer on aluminium alloys by means of chemical reaction. The reaction product of Al2O3 layer of 100 μm in thickness has been formed using a powder mixture of silicon oxide and aluminium by laser processing. It turns out that the large amount of heat from the exothermic reaction has a predominate effects on the formation of the oxide layer. Further, the negative free energy of the reaction may promote the metal/oxide wetting. The micro-hardness and wear tests proved that the oxide layer is hard and strong. A mullite intermediate layer between aluminium and oxide have been identified by TEM. The atomic structure and defects of the reaction layer have been imaged at high resolution electron microscope. (orig.)

  10. Electrodeposition of iron and iron-aluminium alloys in an ionic liquid and their magnetic properties.

    Giridhar, P; Weidenfeller, B; El Abedin, S Zein; Endres, F

    2014-05-28

    In this work we show that nanocrystalline iron and iron-aluminium alloys can be electrodeposited from the ionic liquid 1-butyl-1-methylpyrrolidinium trifluoromethylsulfonate, [Py1,4]TfO, at 100 °C. The study comprises CV, SEM, XRD, and magnetic measurements. Two different sources of iron(ii) species, Fe(TfO)2 and FeCl2, were used for the electrodeposition of iron in [Py1,4]TfO. Cyclic voltammetry was employed to evaluate the electrochemical behavior of FeCl2, Fe(TfO)2, and (FeCl2 + AlCl3) in the employed ionic liquid. Thick iron deposits were obtained from FeCl2/[Py1,4]TfO at 100 °C. Electrodeposition of iron-aluminium alloys was successful in the same ionic liquid at 100 °C. The morphology and crystallinity of the obtained deposits were investigated using SEM and XRD, respectively. XRD measurements reveal the formation of iron-aluminium alloys. First magnetic measurements of some deposits gave relatively high coercive forces and power losses in comparison to commercial iron-silicon samples due to the small grain size in the nanometer regime. The present study shows the feasibility of preparing magnetic alloys from ionic liquids. PMID:24715034

  11. Predicting tensile strength of friction stir welded AA6061 aluminium alloy joints by a mathematical model

    AA6061 aluminium alloy (Al-Mg-Si alloy) has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to weight ratio and good corrosion resistance. Compared to the fusion welding processes that are routinely used for joining structural aluminium alloys, friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force etc., and tool pin profile play a major role in deciding the joint strength. An attempt has been made to develop a mathematical model to predict tensile strength of the friction stir welded AA6061 aluminium alloy by incorporating FSW process parameters. Four factors, five levels central composite design has been used to minimize number of experimental conditions. Response surface method (RSM) has been used to develop the model. Statistical tools such as analysis of variance (ANOVA), student's t-test, correlation co-efficient etc. have been used to validate the developed model. The developed mathematical model can be effectively used to predict the tensile strength of FSW joints at 95% confidence level

  12. Application of spectral analysis of the electrochemical noise to the investigation of aluminium alloy pitting corrosion

    The objective of this research is to decode (at least partially) the nature of the information contained in the electrochemical noise associated with the pitting corrosion phenomenon in aluminium alloys. After a general presentation of aluminium and its alloys and a report of a bibliographical study on the electrochemical noise, the author gives an overview of a theoretical approach of stochastic phenomena, and of an experimental approach. Then, the experimental investigation of the electrochemical noise in the case of pitting corrosion leads to a noise control law, to a study of the structure of pitting growth, and to the elaboration of a procedure of assessment of spectral characteristics of this noise. The author reports a systematic study of the electrochemical noise with respect to the parameters of the control law. Results allow a quantitative characterization of pitting corrosion resistance of the studied alloys, notably by using the kinetic aspect of pitting growth and the structure of pitting corrosion. The author discusses the physicochemical nature of random fluctuations which build up the noise. He proposes a more precise explanation of phenomena related to initiation and propagation of pitting corrosion on aluminium alloys in marine environment

  13. Investigation of Kelvin probe force microscopy efficiency for the detection of hydrogen ingress by cathodic charging in an aluminium alloy

    Larignon, Céline; Alexis, Joël; Andrieu, Eric; Lacroix, Loïc; Odemer, Grégory; Blanc, Christine

    2013-01-01

    Detecting and locating absorbed hydrogen in aluminium alloys is necessary for evaluating the contribution of hydrogen embrittlement to the degradation of the mechanical properties for corroded or cathodically hydrogen-charged samples. The capability of Kelvin probe force microscopy (KFM) to overcome this issue was demonstrated. Aluminium alloy samples were hydrogenated by cathodic polarisation in molten salts (KHSO4/NaHSO4.H2O). The presence of absorbed hydrogen was revealed; the affected zon...

  14. Aluminium EN AC-AlSi12 alloy matrix composite materials reinforced by Al2O3 porous preforms

    Nagel, A.; M. Kremzer; L.A. Dobrzański,

    2007-01-01

    Purpose: The purpose of this work is to elaborate the method of manufacturing of composite materials based on porous ceramic preforms infiltrated by eutectic aluminium alloy.Design/methodology/approach: The material for investigations was fabricated by pressure infiltration method of ceramic porous preforms. The eutectic aluminium alloy EN AC – AlSi12 was use as a matrix while as reinforcement were used ceramic preforms fabricated by sintering of Al2O3 Alcoa CL 2500 powder with addition of po...

  15. HARDNESS VERSUS TIME DEPENDENCY DURING ARTIFICIAL AGEING OF AlMgSi0.5 ALUMINIUM ALLOY

    Mimica, Ratko

    2015-01-01

    Al-Mg-Si aluminium alloy are characterized by excellent deformability, but mechanical properties are not significant in extruded state. Improvement of mechanical properties is achieved by heat treatment, a process which allows formation of metastable precipitates during subsequent ageing. In this work, hardness versus time dependency for artificially aged AlMgSi0.5 (EN AW-6060) aluminium alloy at 185°C is presented, along with qualitative and quantitative analysis of results.

  16. Study of the Fatigue Life and Weight Optimization of an Automobile Aluminium Alloy Part under Random Road Excitation

    Saoudi, A.; Bouazara, M.; Marceau, D.

    2010-01-01

    Weight optimization of aluminium alloy automobile parts reduces their weight while maintaining their natural frequency away from the frequency range of the power spectral density (PSD) that describes the roadway profile. We present our algorithm developed to optimize the weight of an aluminium alloy sample relative to its fatigue life. This new method reduces calculation time; It takes into account the multipoint excitation signal shifted in time, giving a tangle of the constraint signals of ...

  17. Appearance of anodised aluminium: Effect of alloy composition and prior surface finish

    Aggerbeck, Martin; Canulescu, Stela; Dirscherl, Kai; Johansen, Villads Egede; Engberg, Sara Lena Josefin; Schou, Jørgen; Ambat, Rajan

    2014-01-01

    Effect of alloy composition and prior surface finish on the optical appearance of the anodised layer on aluminium alloys was investigated. Four commercial alloys namely AA1050, Peraluman 706, AA5754, and AA6082 were used for the investigation. Microstructure and surface morphology of the substrate...... prior to anodising were analysed using scanning electron microscopy and atomic force microscopy. The optical appearance of the anodised surface with and without sealing was investigated using a photography setup, photospectrometry and bidirectional reflectance distribution function. It was found that...... the roughness of the as-etched surface increases with the degree of alloying due to second phase particles making the reflection more diffused, and that the as-etched surface morphology is similar to the oxide–substrate interface after anodising. Proper polishing is achieved on hard alloys and the...

  18. Corrosion of alloys of the niobium--titanium--aluminium system

    The mechanical properties and corrosion resistance of niobium--titanium--aluminum alloys in 20 percent HCl and 40--75 percent H2SO4 at 40 and 1000C are considered. Current density vs potential and corrosion rate vs potential potentiostatic curves plotted in 75 percent H2SO4 at 1400C for the alloys with different titanium contents at a constant content of aluminum and also for alloys with a constant titanium content at different contents of aluminum are given. It was shown that the corrosion resistance of the alloys in 75 percent H2SO4 at 1400C is an exponential function of the atomic content of the alloying components (Ti, Al) in them; aluminum vitiates the corrosion resistance very strongly

  19. Accelerated growth of oxide film on aluminium alloys under steam: Part I: Effects of alloy chemistry and steam vapour pressure on microstructure

    Din, Rameez Ud; Gudla, Visweswara C.; Jellesen, Morten S.;

    2015-01-01

    Aluminium alloys were treated with steam of varying vapour pressures which resulted in the growth of aluminium oxyhydroxide layers of an average thickness of ~450–825 nm. The microstructure and composition of the generated layers were characterised by GD-OES, FEG-SEM, GI-XRD and TEM. The thicknes...

  20. Impact toughness improvement of high-strength aluminium alloy by intrinsic and extrinsic fracture mechanisms via hot roll bonding

    A multilayer aluminium laminate comprising 10 layers of Al-Zn-Mg-Cu alloy (82 vol.%) and nine layers of pure aluminium (18 vol.%) has been processed by hot rolling. The rolled laminate was characterized by electron backscattering diffraction, Charpy impact and shear tests. The multilayer laminate showed an outstanding Charpy impact toughness, which was 18 times higher than that for the as-received Al-Zn-Mg-Cu alloy. The improvement in damage tolerance was due to the high volume fraction of the high-strength aluminium and extrinsic fracture mechanisms.

  1. Braze Welding TIG of Titanium and Aluminium Alloy Type Al – Mg

    Winiowski A.

    2016-03-01

    Full Text Available The article presents the course and the results of technological tests related to TIG-based arc braze welding of titanium and AW-5754 (AlMg3 aluminium alloy. The tests involved the use of an aluminium filler metal (Al99.5 and two filler metals based on Al-Si alloys (AlSi5 and AlSi12. Braze welded joints underwent tensile tests, metallographic examinations using a light microscope as well as structural examinations involving the use of a scanning electron microscope and an X-ray energy dispersive spectrometer (EDS. The highest strength and quality of welds was obtained when the Al99.5 filler metal was used in a braze welding process. The tests enabled the development of the most convenient braze welding conditions and parameters.

  2. Effect of Process Parameters of Friction Stir Welded Joint for Similar Aluminium Alloys H30

    Vanita S. Thete

    2015-05-01

    Full Text Available In this paper the effect of process parameters of friction stir welded joint for similar aluminium alloys H30 was studied. Taper cylindrical with three flutes all made of High speed steel was used for the friction stir welding (FSW aluminium alloy H30 and the tensile test of the welded joint were tested by universal testing method. The optimization done using detailed mathematical model is simulated by Minitab17. In this investigation, an effective approach based on Taguchi method, has been developed to determine the optimum conditions leading to higher tensile strength. Experiments were conducted on varying rotational speed, transverse speed, and axial force using L9 orthogonal array of Taguchi method. The present study aims at optimizing process parameters to achieve high tensile strength.

  3. RESEARCH OF FATIGUE AND MECHANICAL PROPERTIES AlMg1SiCu ALUMINIUM ALLOYS

    Mária Mihaliková

    2015-11-01

    Full Text Available The paper is concerned with an analysis of utility and fatigue properties of industrially produced aluminium alloy, specifically EN AW 6061 (AlMg1SiCu, reinforced with the particles of SiC. The following properties were subject to evaluation: microstructure and sub-structure, mechanical characteristics. All of these mechanical properties in pre- and post- equal channel angular pressed (ECAP state have been studied. The hardness was evaluated by Vickers hardness test at the load of HV10. The significant part the thesis was devoted to the fatigue properties at cyclic load in torsion. The presented results demonstrate well that the combination of fractography and microscopy can give a significant contribution to the knowledge of initiation and propagation crack in the aluminium alloy.

  4. Friction Stir Processing of Aluminium-Silicon Alloys

    Chun Yip Chan

    2011-01-01

    Friction Stir Processing (FSP) has the potential for locally enhancing the properties of Al-Si alloy castings, for demanding applications within the automotive industry. In this thesis, the effect of FSP has been examined on three different cast Al-Si alloys:i) A Hypoeutectic Al-8.9wt%Si Alloyii) A Hypereutectic Al-12.1wt%Si Alloyiii) A Hypereutectic Al-12.1wt%Si-2.4wt%Ni AlloyThe influence of different processing parameters has been investigated at a fundamental level. Image analysis of part...

  5. High-Rate Compaction of Aluminium Alloy Foams

    The response of aluminium foams to impact can be categorised according to the impact velocity. Tests have been carried out at a range of impact velocities from quasi-static to velocities approaching the speed of sound in the foam. Various experimental arrangements have been employed including pneumatic launcher tests and plate impact experimants at velocities greater than 1000 m s-1. The quasi-static compression behaviour was approximately elastic, perfectly-plastic, locking. For static and dynamic compression at low impact velocities the deformation pattern was through the cumulative multiplication of discrete, non-contiguous crush bands. Selected impact tests are presented here for which the impact velocity is less than the velocity of sound, but above a certain critical impact velocity so that the plastic compression occurs in a shock-like manner and the specimens deform by progressive cell crushing. Laboratory X-ray microtomography has been employed to acquire tomographic datasets of aluminium foams before and after tests. The morphology of the underformed foam was used as the input dataset to an Eulerian code. Hydrocode simulations were then carried out on a real microstructure. These simulations provide insight to mechanisms associated with the localization of deformation

  6. Heat input effect of friction stir welding on aluminium alloy AA 6061-T6 welded joint

    Sedmak Aleksandar

    2016-01-01

    Full Text Available This paper deals with the heat input and maximum temperature developed during friction stir welding with different parameters. Aluminium alloy (AA 6061-T6 has been used for experimental and numerical analysis. Experimental analysis is based on temperature measurements by using infrared camera, whereas numerical analysis was based on empirical expressions and finite element method. Different types of defects have been observed in respect to different levels of heat input.

  7. Numerical modelling of complex shaped particle break-up with application to rolling of aluminium alloys

    Moulin, Nicolas

    2008-01-01

    The aluminium alloy AA5182, largely employed in the form of plates used for the body panels in automotive industry, contains intermetallic particles Mg2Si and AlxFe. In as cast state, these particles (of a size > 50 µm) present complex shapes. During hot rolling, the particles are broken and redistributed in the sheet metal. However, the size and the spatial distribution of the intermetallic particles mainly control the formability of sheets after cold transformation.This work identifies morp...

  8. Structure and properties of ultrafine-grained aluminium alloys prepared by equal-channel angular pressing

    Dám, Karel; Jäger, Aleš; Vystavěl, Tomáš; Lejček, Pavel

    Aachen: RWTH Aachen University, 2010 - (Epple, D.; Nick, M.; Strämke, M.; Zilkens, C.), s. 141-144 ISBN N. [ ISDM 2010. Aachen (DE), 16.09.2010-18.09.2010] R&D Projects: GA AV ČR KAN300100801 Institutional research plan: CEZ:AV0Z10100520 Keywords : Equal-Channel Angular Pressing * aluminium alloys * grain refinement Subject RIV: BM - Solid Matter Physics ; Magnetism

  9. Ultrafine-grained aluminium alloys prepared by severe plastic defomation (ECAP)

    Dám, Karel

    Leoben: The Austrian Society for Metallurgy and Materials, 2011, 203-207. ISBN 978-3-200-02155-6. [International student´s day of Metallurgy /18./. Leoben (AT), 17.03.2011-19.03.2011] R&D Projects: GA AV ČR KAN300100801 Institutional research plan: CEZ:AV0Z10100520 Keywords : Equal-Chanel Angular Pressing * aluminium alloys * grain refinement Subject RIV: BM - Solid Matter Physics ; Magnetism

  10. Micro-scale abrasion behaviour of electroless Ni-P-SiC coating on aluminium alloy

    Franco, M.; Sha, Wei; Malinov, Savko

    2014-01-01

    Electroless nickel (EN) and electroless nickel composite (ENC) coatings were deposited on aluminium alloy substrate, LM24. The micro abrasion test was conducted to study the wear behaviour of the coatings with the effect of SiC concentration. Microhardness of the coatings was tested also. The wear scars were analysed using optical microscope and scanning electron microscope (SEM). The wear resistance was found to be improved in composite coating that has higher microhardness as compared to pa...

  11. The magnitude of heat treatment induced residual stresses and the thermal stress relief of aluminium alloys

    Robinson, J S; Tanner, D.A

    2002-01-01

    To produce useful strengthening, precipitation hardenable aluminium alloys rely on rapid quenching from the solution heat treatment temperature to suppress the formation of coarse equilibrium second phases. An unavoidable consequence of the rapid quenching of thick sections is the severe thermal gradients that quickly develop in the material. The attendant inhomogeneous plastic flow can then result in the establishment of residual stresses. Established procedures exist to minim...

  12. Microstructure and hot tearing of 6000 series aluminium alloys laser welds

    Fabregue, Damien

    2004-01-01

    There has been a rapid growth in the use of the laser welding process due to its higher productivity rate compared to conventional processes. However its development in the field of aluminium alloys has been limited due to the presence of solidification defects (e.g. porosity, hot cracking). This study is focused on the understanding of the problem of hot cracking during welding. Numerous welding tests were done under different conditions, followed by microstructural examinations so as to und...

  13. Tensile behaviour of aluminium 7017 alloy at various temperatures and strain rates

    Ravindranadh Bobbili

    2016-04-01

    Full Text Available The objective of the present study is to carry out high strain rate tensile tests on 7017 aluminium alloy under different strain rates ranging from 0.01, 500, 1000 and 1500 s−1 and at temperatures of 25, 100, 200 and 300 °C. Quasi-Static tensile stress–strain curves were generated using INSTRON 8500 machine. Johnson-Cook (J-C constitutive model was developed for 7017 aluminium alloy based on high strain rate tensile data generated from split Hopkinson tension bar (SHTB at various temperatures. This study evidently showed an improvement in dynamic strength as the strain rate increases. The predictions of J-C model are observed to be in consistence with the experimental data for all strain rates and temperatures. The fracture surfaces of specimens tested were studied under SEM. The change in fracture mode has been observed at different strain rates. The shear mode of fracture is dominant at lower strain rates (0.01 and 500 s−1; whereas cup- and cone-like surface representing dimple structure is found at the higher strain rates (1000 and 1500 s−1. The numbers of dimples at high strain rates are more than the quasi-static and intermediate strain rates. It is also observed that the flow stress decreases with increase in temperature. The 7017 aluminium alloy demonstrates thermal softening at higher temperatures. So when the temperature is more than 200 °C at these strain rates, thermal softening is predominant mode of deformation mechanism. It is found that when the temperature increases to 200 °C, the number of dimples rises and the dimple size of 7017 aluminium alloy is larger than at lower temperatures.

  14. High-temperature mechanical properties of aluminium alloys reinforced with boron carbide particles

    The mechanical properties of particulate-reinforced metal-matrix composites based on aluminium alloys (6061 and 7015) at high temperatures were studied. Boron carbide particles were used as reinforcement. All composites were produced by hot extrusion. The tensile properties and fracture analysis of these materials were investigated at room temperature and at high temperature to determine their ultimate strength and strain to failure. The fracture surface was analysed by scanning electron microscopy

  15. Effect of equal channel angular pressing (ECAP) on creep in aluminium alloys

    Sklenička, Václav; Dvořák, Jiří; Král, Petr; Kvapilová, Marie; Svoboda, Milan; Saxl, Ivan; Horita, Z.

    2007-01-01

    Roč. 539-543, - (2007), s. 2904-2909. ISSN 0255-5476 R&D Projects: GA AV ČR(CZ) IAA2041301 Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z10190503 Keywords : equal-channel angular pressing * aluminium alloy s * ultrafine-grained microscructure Subject RIV: JG - Metallurgy Impact factor: 0.399, year: 2005

  16. Substantial enhancement in the anticorrosivity of aluminium alloy 6061 by doxycycline hydrochloride drug

    Pavithra, Mudigere Krishnegowda; Venkatesha, Thimmappa Venkatarangaiah; Kumar, Mudigere Krishnegowda Punith; Anantha, Nanjanagudu Subba Rao

    2015-01-01

    The significant anticorrosive property of the antibiotic drug doxycycline hydrochloride (DCH) was investigated by electrochemical techniques such as potentiodynamic polarization, electrochemical impedance and chronoamperometric techniques. DCH inhibited the pitting corrosion of aluminium alloy 6061 (AA6061) in 3.5% NaCl media with 90% efficiency. The adsorption of DCH on AA6061 conform Langmuir isotherm by means of physisorption. Quantum chemical calculations were evaluated to ascertain the ...

  17. Metallurgical bond between magnesium AZ91 alloy and aluminium plasma sprayed coatings

    Kubatík, Tomáš František; Pala, Zdeněk; Neufuss, Karel; Vilémová, Monika; Mušálek, Radek; Stoulil, J.; Slepička, P.; Chráska, Tomáš

    2015-01-01

    Roč. 282, November (2015), s. 163-170. ISSN 0257-8972 R&D Projects: GA ČR(CZ) GP14-31538P Institutional support: RVO:61389021 Keywords : Plasma spraying * AZ91 magnesium alloy * Aluminium * Metallurgical bond * X-ray diffraction Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 1.998, year: 2014 http://www.sciencedirect.com/science/article/pii/S0257897215303297

  18. Advances in aluminium alloy products for structural applications in transportation

    Staley, J.; Lege, D.

    1993-01-01

    This paper describes the needs of the aviation and automotive markets for structural materials and presents examples of developments of aluminum alloy products to fill these needs. Designers of aircraft desire materials which will allow them to design lightweight, cost-effective structures which have the performance characteristics of durability and damage tolerance. Their needs are being met by new and emerging materials varying from Al-Li alloys for thick structure, high-strength plate and ...

  19. Intergranular corrosion of AA6000-series aluminium alloys

    Svenningsen, Gaute

    2005-01-01

    Even though highly corrosion resistant in general, AlMgSi (6000-series) alloys may sometimes develop susceptibility to intergranular corrosion (IGC). In this work the effect of Cu content and various thermomechanical treatments on IGC of AlMgSi model alloy extrusions of nominal composition 0.55 wt% Mg and 0.60 wt%Si was investigated. The corrosion susceptibility was tested according to the standard BS 11846 method B, which essentially involved degreasing, alkaline etching, desmutting in conce...

  20. Inhibitive Behaviour of Corrosion of Aluminium Alloy in NaCl by Mangrove Tannin

    Anticorrosion potential of mangrove tannins on aluminium alloys AA6061 in NaCl solution has been studied using potentiodynamic polarisation method and scanning electron microscopy (SEM). The study was carried out in different pH of corrosive medium in the absence and presence of various concentrations of tannin. The corrosion inhibition behaviour of the mangrove tannin on AA6061 aluminium alloy corrosion was found to be dependant on the pH of NaCl solution. Our results showed that the inhibition efficiency increased with increasing tannins concentration in chloride solution at pH 6. Treatment of aluminium alloy 6061 with all concentrations of mangrove tannins reduced the current density, thus decreased the corrosion rate. Tannins behaved as mixed inhibitors at pH 6 and reduction in current density predominantly affected in cathodic reaction. Meanwhile, at pH 12, addition of tannins shifted the corrosion potential to more cathodic potentials and a passivating effect was observed in anodic potentials. SEM studies have shown that the addition of tannins in chloride solution at pH 12 reduced the surface degradation and the formation of pits. (author)

  1. RAPID NONDESTRUCTIVE TESTING OF HEAT-TREATMENT QUALITY OF 2014 ALUMINIUM ALLOY

    1999-01-01

    Since there is a single-valued reverse "C" shape relation between the displayed values of low frequency WJF-38 type micro-computer-based automatic metal material separator and the hardness of 2014 aluminium alloy after solid solution treatments at different temperatures and natural aging, moreover, the parts without sufficient solid solution, the over-burnt parts and the hardening crack parts respectively appear at the top and bottom of the reverse "C" shape relationship curve, the hardness of the 2014 aluminium alloy can be quantitatively determined by the WJF-38 instrument. Its Brinell hardness, Rockwell hardness and Vickers hardness values can be directly displayed. The parts without sufficient solid solution, the over-burnt parts and the hardening cracked parts can also be accurately separated by using the WJF-38 instrument. Furthermore,there is also a reverse "C" shape relation between the hardness of 2014 aluminium alloy after artificial aging treatment and the displayed value of the WJF-38 instrument. The precision of the hardness tested by the WJF-38 instrument is about HRB ± 1.3, and the separating speed can reach 1500 parts per hour.

  2. Characteristics of aluminium-scandium alloy thin sheets obtained by physical vapour deposition

    Thin sheets of an age-hardenable aluminium-scandium alloy were deposited by direct current magnetron sputtering. As targets an aluminium-scandium pre-alloy with a scandium content of 2.0 mass% (size 88 x 500 mm) was applied. The substrates to be coated consisted of thin steel sheets which after deposition were dissolved in an oxidizing medium. In this way, free-standing sheets of less than 30 μm thickness of the aluminium-scandium alloy were received. Two deposition temperatures, 37 and 160 oC, were applied. The as-received sheets showed a typical columnar structure. Two post-treatments of the sheets were applied: a cold isostatic pressing and an artificial ageing for 1 h at temperatures between 200 and 400 oC. The strength of the sheets was measured by tensile tests. The employed specimens had a width of 10 mm and were gained from the sheets by cutting. During testing, load and strain were measured by a 1000 N load cell and a video extensometer, respectively. The as-deposited specimens show a tensile strength of 350 MPa. Artificial ageing at 300 oC increases the tensile strength to more than 400 MPa. It could be shown that during tensile tests cracks are initialized at coating defects.

  3. Microstructures and Properties of Aluminium-Magnesium Alloys with Additions of Manganese, Zirconium and Scandium

    Johansen, Arve

    2000-01-01

    The present work reports on the effect of Mn-, Zr- and Sc-additions upon hot deformation properties, recrystallization properties and mechanical properties for different temper conditions of Al-Mg alloys.It can be stated that the addition of Mn, Zr and Sc improves the recrystallization properties and the mechanical properties of Al-Mg alloys. It should be emphasised that the precipitation of the metastable cubic Al3Zr and the stable cubic Al3(Sc,Zr) is favourable in an aluminium-magnesium mat...

  4. Protection of 2024-T3 aluminium alloy by corrosion resistant phytic acid conversion coating

    Shi, Hongwei; Han, En-Hou; Liu, Fuchun; Kallip, Silvar

    2013-09-01

    The corrosion protection properties of environmentally friendly phytic acid conversion coatings were studied on 2024-T3 aluminium alloy. The films were prepared under acidic conditions with various pH values and characterised by SEM, EDS, ATR-FTIR and electrochemical techniques. The results indicate that the conversion coatings obtained by immersing the alloy in phytic acid solutions at pH from 3 to 5.5 provide excellent corrosion resistance. ATR-FTIR confirms that the film is formed by deposition of reaction products between Al3+ and phosphate groups in phytic acid molecules. The conformation models of the deposition film are proposed.

  5. Aluminium Alloy AA6060 surface treatment with high temperature steam containing chemical additives

    Din, Rameez Ud; Tabrizian, Naja; Jellesen, Morten S.;

    2015-01-01

    The steam treatment process was employed to produce a conversion coating on aluminium alloy AA6060. The changes in microstructure and its effect on corrosion resistance properties were investigated. Various concentrations of KMnO4 containing Ce(NO3)3 was injected into the steam and its effect on...... the formation of steam-based conversion coating was evaluated. The use of Mn-Ce into the steam resulted in incorporation of these species into the conversion coating, which resulted in improved corrosion resistance of the alloy substrate....

  6. THE EFFECT OF THE ALUMINIUM ALLOY SURFACE ROUGHNESS ON THE RESTITUTION COEFFICIENT

    Stanisław Bławucki

    2015-08-01

    Full Text Available The paper presents the results of research on the effect of the surface roughness of aluminum alloy on its coefficient of restitution. It describes the current method of finishing the workpiece surface layer after cutting and innovative measuring device which was used in the research. The material used in the research was aluminium alloy EN AW 7075. The paper also presents a relationship between the coefficient of restitution and surface roughness of the milled samples as well as impressions left by bead in function of velocity and a sample surface roughness.

  7. Analysis of intermetallic particles in AlSi1MgMn aluminium alloy

    G. Mrówka-Nowotnik; J. Sieniawski; M. Wierzbińska

    2007-01-01

    Purpose: The main objective of this study was to analyze the morphology and composition of complexmicrostructure of the intermetallic phases in AlSi1Mg alloy.Design/methodology/approach: In this study, several methods were used such as: optical light microscopy(LM), transmission (TEM) and scanning (SEM) electron microscopy in combination with X-ray analysis (EDS)using polished sample, and X-ray diffraction (XRD) to identify intermetallics in AlSi1MgMn aluminium alloy.Findings: The results sho...

  8. Effect of Laser Feeding on Heat Treated Aluminium Alloy Surface Properties

    Labisz K.

    2016-06-01

    Full Text Available In this paper are presented the investigation results concerning microstructure as well as mechanical properties of the surface layer of cast aluminium-silicon-copper alloy after heat treatment alloyed and/ or remelted with SiC ceramic powder using High Power Diode Laser (HPDL. For investigation of the achieved structure following methods were used: light and scanning electron microscopy with EDS microanalysis as well as mechanical properties using Rockwell hardness tester were measured. By mind of scanning electron microscopy, using secondary electron detection was it possible to determine the distribution of ceramic SiC powder phase occurred in the alloy after laser treatment. After the laser surface treatment carried out on the previously heat treated aluminium alloys, in the structure are observed changes concerning the distribution and morphology of the alloy phases as well as the added ceramic powder, these features influence the hardness of the obtained layers. In the structure, there were discovered three zones: the remelting zone (RZ the heat influence zone (HAZ and transition zone, with different structure and properties. In this paper also the laser treatment conditions: the laser power and ceramic powder feed rate were investigated. The surface laser structure changes in a manner, that there zones are revealed in the form of. This carried out investigations make it possible to develop, interesting technology, which could be very attractive for different branches of industry.

  9. Study on segregation of aluminium-uranium alloys

    The relations between alloy solidification and solute segregation were considered. The solidification structure and the solute redistribution during the solidification of alloys with dendritic micro morphology were studied. The macro and micro segregation theories were reviewed. The mechanisms that could change the solidification structure were taken into account in the context of more homogeneous alloy production. Aluminum alloys solidification structures and segregation were studied experimentally in the 13 to 45% uranium range, usually considering solidification in static molds. The uranium alloys with up to 20% uranium were studied both for solidification in ingot molds and for controlled directional solidification. It was verified that these alloy compositions had structures similar to those of hipoeutectic alloys, showing an a phase with dendritic morphology and inter dendritic eutectic. For the alloys with more than 25% uranium, it was observed the formation of UAl3 and UAl4 phases with dendritic morphology. The dendritic UAl3, phase morphology was affected both by the solute concentration in the alloy and by the growth rate. The dendritic UAl3 phase non-singular aspect could be destroyed with decrease of the alloy solute concentration. In the alloys obtained with higher cooling rates it was found a tendency for the formation of substantial quantities of equi axial crystals of the solute enriched phases in the central regions of the ingot upper half. In the more external regions it was observed dendritic growth of these phases, for alloy compositions with over 25% uranium. An adequate reduction in the cooling rate changed the solidification structure form and distribution, as well as the segregation type and intensity. The uranium content in the solidified macro structures is presented as a function of: cooling rate, superheating, mold size, mold form and its temperature, number of remelting and time for the melt homogenization and agitation. It was observed

  10. Increasing of founding properties of secondary aluminium alloys

    O.V. Lyutova

    2013-06-01

    Full Text Available Purpose. To study the influence of metallurgical factors of production on casting properties of secondary aluminum alloy АК9М2. Methodology. For the experimental melts shaving amount in a charge, iron content and the quantity of modifier additive were chosen as independent variables. The components of modifier were being changed in the intervals of 25…40 % Na2CO3, 12…20 % SiC, 3…8 % Ti, the other – S. The microstructure of alloys was investigated under a light microscope, using the method of quantitative metallography. Influence analysis of certain parameters of alloys was conducted by mathematical statistics methods. The influence of shaving additions, iron and modifier amount on liquidity and porosity of the resulting alloys was studied. Findings. The paper shows that the increase of shaving content in the charge from 1 to 19 % and iron content in alloy from 0.66 to 2.34 % resulted in the decline of alloy liquidity on 30…35 %. Simultaneously the linear shrinkage reduction for 18…20 % and the porosity increase from 0.5 to 2.5 points were observed. The presented changes of alloy casting properties are conditioned by the amount of intermetallic phases of unfavorable form and its capacity for aeration. Increase of modifier additive from 0.02 to 0.15 % resulted in the liquidity increase on 10…15 %, the increase of linear shrinkage on 30…35 % and porosity decline from 2.5 to 0.5 points. At the same time a change of form of intermetallic phases and increase of their evenness were observed. Originality. The increase of iron concentration in silumin composition is accompanied by the decline of its liquidity. Thus, the rate of decline of alloy liquidity is proportional to the amount of dissolved iron. The character of iron influence is caused by formation of high temperature intermetallic compounds of the type Al3Fe, Al5SiFe, which promote the metal viscidity. Practical value. Practical use of the obtained scientific results would

  11. Influence of constitutional liquation on corrosion behaviour of aluminium alloy 2017A

    The purpose of this work was to investigate microstructural aspects of constitutional liquation in the aluminium alloy 2017A and to determine its effect on corrosion behaviour of this alloy. Non-equilibrium melting of the alloy in the naturally aged condition was provoked by rapid heating above the eutectic temperature and immediate cooling in air. Corrosion testing was performed by exposure to a marine onshore atmosphere. The microstructure examinations were carried out using light microscopy, scanning electron microscopy, X-ray energy dispersion and X-ray diffraction analysis. It was found that, due to rapid heating rate, coarse θ (Al2Cu) particles were melted by constitutional liquation and this way introduced strong susceptibility of 2017A alloy to intergranular corrosion.

  12. Ageing and work-hardening behaviour of a commercial AA7108 aluminium alloy

    In the 7xxx aluminium alloying system several mechanisms influence the hardening behaviour of the alloys, e.g. particle size and distribution, dislocation density and alloying elements in solid solution. This work is an experimental study of ageing and work-hardening considering a commercial AA7108 alloy in the as-cast and homogenized condition. Tensile specimens have been exposed to a solution heat treatment and a two-step age-hardening treatment with varying time at the final temperature. The tensile data for the different tempers have been evaluated in elucidation of already existing models based on a one-parameter framework. The precipitate size and distribution have been further investigated in the transmission electron microscope for a selection of tempers, and the influence of these parameters on the work-hardening behaviour has been discussed.

  13. Phase-oriented surface segregation in an aluminium casting alloy

    There have been many reports of the surface segregation of minor elements, especially Mg, into surface layers and oxide films on the surface of Al alloys. LM6 casting alloy (Al-12%Si) represents a challenging system to examine such segregation as the alloy features a particularly inhomogeneous phase structure. The very low but mobile Mg content (approximately 0.001 wt.%), and the surface segregation of modifiers such as Na, mean the surface composition responds in a complex manner to thermal treatment conditions. X-ray photoelectron spectroscopy (XPS) has been used to determine the distribution of these elements within the oxide film. Further investigation by dynamic secondary ion mass spectrometry (DSIMS) confirmed a strong alignment of segregated Na and Mg into distinct phases of the structure.

  14. Structural properties of molten dilute aluminium-transition metal alloys

    The short-range order in liquid binary Al-rich alloys (Al-Fe, Al-Ti) was studied by x-ray diffraction. The measurements were performed using a novel containerless technique which combines aerodynamic levitation with inductive heating. The average structure factors, S(Q), have been determined for various temperatures and compositions in the stable liquid state. From S(Q), the pair correlation functions, g(r), have been calculated. The first interatomic distance is nearly temperature-independent, whereas the first-shell coordination number decreases with increasing temperature for all the alloys investigated. For the Al-Fe alloys, room-temperature scanning electron microscropy (SEM) studies show the formation of a microstructure, namely the existence of Al13Fe4 inclusions in the Al matrix

  15. Development of electron beam welding of 6061-T6 aluminium alloy for the Jules Horowitz Reactor - Development of the electron beam welding of the 6061-T6 aluminium alloy

    In a text and in a Power Point presentation, the author first evokes the interesting properties of the 6061-T6 aluminium alloy and the problems its raises as far as welding is concerned. He also evokes that hundreds of tests and characterizations (destructive and non destructive testing) of TIG, MIG and EB (electron beam) welding processes have been performed before the selection of the electron beam welding process. The author discusses the weldability of aluminium alloys, and more particularly that of the 6061-T6 alloy (control of mechanical properties of the welded joint, hot cracking during welding, solidification or liquation)

  16. Corrosion behaviour of aluminium-magnesium alloys in molten sodium

    2000-01-01

    The corrosion behaviour of the Al-1% Mg, A1-3% Mg, A1-5% Mg and A1-3% Mg-0.15%Zr alloys in moltensodium was investigated. The morphology of the corrosion products and the alloying element distribution of the specimenswere analyzed by using OM, SEM and EDS. The results showed that the effects of the magnesium content and the im-mersion temperature on the corrosion of the specimens are related to β phase (Mg5Al8).

  17. Determination of anisotropy in impact toughness of aluminium alloy 2024 T3 plate

    Siddiqui, M. H.; Hashmi, F.; Junaid, A.

    The research was aimed to quantify the existence of anisotropy in fracture toughness of aluminium alloy 2024 T3 plate (used in aircraft structural members). It was further needed to establish the direction in which the fracture toughness of aluminium alloy 2024 T3 plate is maximum and minimum. This could help ascertain the structural integrity of aircraft structural components; also while designing new components, the knowledge of variation in toughness with respect to direction helps in economizing dead weight of the aircraft. In this research, pursued at the College of Aeronautical Engineering, the anisotropy in toughness of aluminium alloy 2024 T3 plate was analysed using the Charpy V-notch impact toughness test. The effect of specimen orientation on the impact toughness values of the alloy was investigated and compared with known results to verify the reliability of the work and to ascertain the extent of anisotropy in fracture toughness of the said alloy. Charpy impact tests were carried out on ASTM E 23 standard specimens machined at a reference laboratory at room temperature (23° C +/- 2° C). Four different specimen orientations analysed for the purpose of this study were L-S, L-T, T-S and T-L directions. Subsequently, the results obtained at the research centre were then analysed and correlated with morphology of microstructure of the material to establish the reliability of the experimental results. Moreover, an analysis was also done to cater for the possible errors that could affect the fracture toughness values obtained from experimental results. It was concluded that the T-S orientation of the plate had maximum toughness, whereas, minimum toughness was observed in L-T direction.

  18. Study of thermodynamic properties of binary and ternary liquid alloys of aluminium with the elements iron, cobalt, nickel and oxygen

    The present work deals with the thermodynamic study of aluminium liquid alloys with the metals iron, cobalt and nickel. The experiments carried out lead to the activity, at 1600 deg C, of aluminium in the (Al, Fe), (Al, Co), (Al, Ni) liquid alloys. The experimental method used consists in studying the partition of aluminium between the liquid immiscible phases made up with the pairs of metals (Fe, Ag), (Co, Ag), (Ni, Ag). The informations so obtained are used for drawing the isothermal equilibrium phases diagrams sections of (Al, Fe, Ag), (Al, Co, Ag), (Al, Ni, Ag) systems. The study of the partition of silver between lead and aluminium joined with the determinations of several authors allows us to determine the aluminium activity, analytically presented, in the metal M (iron cobalt and nickel). The Wagner's interaction parameters of aluminium in metal M are determined. The results obtained as the equilibrium phases diagrams of (Al, M) systems allow to compare the thermodynamic properties of the Al Fe system in liquid and solid states and to estimate the enthalpies of melting of the AlCo and AlNi intermetallic compounds. The activity, at 1600 deg C, of aluminium in (Al, Fe, Co), (Al, Fe, Ni), (Al, Co, Ni) liquid alloys is estimated through thermodynamic properties of binary components systems by application of several methods leading to results in good agreement. The study of aluminium-oxygen interactions in the liquid metallic solvants M allows us to propose an explanation for the shape of the deoxidation equilibrium line of iron, cobalt and nickel by aluminium and to compare the de-oxidizing power of aluminium toward iron, cobalt and nickel oxides. (author)

  19. Cavitation erosion resistance of microarc oxidation coating on aluminium alloy

    Cheng, Feng [School of Mechanical Engineering, Southeast University, Nanjing, 211189 (China); Jiang, Shuyun, E-mail: jiangshy@seu.edu.cn [School of Mechanical Engineering, Southeast University, Nanjing, 211189 (China); Liang, Jun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 (China)

    2013-09-01

    Two ceramic coatings are prepared on 2124 aluminum alloy by microarc oxidation (MAO) technology. To explore the cavitation erosion resistance of the MAO coating, cavitation tests were performed by using a rotating-disk test rig. The mass losses, surface morphologies, chemical compositions and the phase constituents of the samples after cavitation tests were examined by using digital balance, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The results indicate that the MAO coatings can extend the incubation period of aluminum alloy, and thus enhance the cavitation erosion resistance as compared to the untreated aluminum alloy samples. After duration of 63 h cavitation test, a lot of erosion pits and the particles in various shapes can be observed on the surfaces of the aluminum alloy samples, while only a few erosion pits are observed on the MAO coatings. Moreover, the mean depths of erosion on the MAO coatings are lower in the first 30 h and are independent on erosion time. The results show that the cavitation erosion of MAO coating is governed by water mechanical impaction, resulting from the effects of brittle fracture of the MAO coating.

  20. Microstructures and mechanical properties of an Osprey aluminium 7000 alloy

    Cottignies, L.; Brechet, Y.; Audier, M.; Livet, F.; Louchet, F.; Sainfort, P.

    1993-01-01

    An alloy from the 7000 serie obtained by the Osprey process has been studied both from the microstructural (TEM, SAXS) and from the mechanical viewpoint. The modelling of the mechanical properties and of their anisotropy was performed using both models from physical metallurgy and a self consistent eslastoplastic model.

  1. Castability tests applied to an aluminium-copper alloy

    Garda, B.; Fortin, L; Durand, F.; Durand, Franck

    1993-01-01

    Simplified castability tests were performed on an Al-2%Cu alloy. Measured values of the fluid length can be represented by Ragone's model, giving an estimate for the metal-mould heat transfer coefficient. The grain structure can be considered as a case of columnar-toequiaxed transition in relatively simple flow conditions.

  2. On the friction stir welding of aluminium alloys EN AW 2024-0 and EN AW 5754-H22

    C. Ozarpa

    2007-01-01

    Full Text Available Purpose: Purpose of this paper is investigate the friction stir welding capability of the EN AW 2024-0 and EN AW 5754-H22 Al alloys are studied, because two aluminium alloys are widely used in the industry and friction stir welding is getting widened to be used to join the aluminium alloys.Design/methodology/approach: Friction stir welding (FSW is a new solid fhase technique invented and patented for aluminium alloys. EN AW 2024-0 and EN AW 5754-H22 are aluminium alloys can be welded by fusion welding, but many welding problems arises from fusion welding. While the friction stir welding is a solid state welding process, some problems may be prevented.Findings: It is found in the course that these two aluminium alloys can be friction stir welded if fhe welding parameters are carefully selected. Hardness value in weld area for EN AW 2024-0, there is an increase about 10-40 Hv. Because of this is recrystalization and getting smaller grains. For EN AW 5754-H22 there is a decrease of hardness value because of recrystalization. Welding performance of EN AW 2024-0 is reached to 96.6 %. This value is 57 % for EN AW 5754-H22. It is possible to perform dissimilar welding using different aluminium alloys. elding performance of dissimilar aluminium alloys EN AW 2024-0 and EN AW 5754-H22 is reached a value of 66.39%.Research limitations/implications: Research limitations are that the design of the welding probe which is used in the experiments is changed, the speed of the welding can be improved. The material of the welding probe can be changed.Originality/value: The aluminium alloys EN AW 2024-0 and EN AW 5754-H22 are widely used ones but the friction stir weldability is not investigated so far. It is found that if the welding parameters are carefully selected, these aluminium alloys can be friction stir welded succesfuly.

  3. Influence of microstructure on work-hardening and ductile fracture of aluminium alloys

    Highlights: • Microstructural effects on work-hardening and fracture of aluminium are studied. • Four alloys with three different processing steps are tested in uniaxial tension. • An experimental–numerical approach is used to determine the work-hardening. • The microstructure has a strong effect on both work-hardening and ductility. • A linear decrease in failure strain with yield stress for the materials is found. - Abstract: The effect of microstructure on the work-hardening and ductile fracture of aluminium alloys was studied using an experimental–numerical approach. Four aluminium alloys with different strength and particle content were tested in uniaxial tension after the following subsequent processing steps: (1) casting and homogenisation, (2) extrusion, and (3) cold rolling followed by heat treatment. The latter processing step was carried out to obtain a recrystallized grain structure with random crystallographic texture. The alloys were two AlFe alloys with different Fe content, one AlMn alloy and one AlMgSi alloy. The grain structure, particle distribution and crystallographic texture were determined for all combinations of alloy and processing route using optical and scanning electron microscopy. Tensile tests were carried out on axisymmetric samples to obtain the true stress–strain curves to failure and the true failure strain of the materials, using a laser-based measuring system. Based on numerical simulations of the tensile tests, the equivalent stress–strain curves were determined to failure, assuming J2 flow theory. The results showed that the microstructure had a marked effect on both work-hardening and ductility, whilst the ductile fracture mechanism remained unchanged. The plastic anisotropy, induced by the extrusion process and not entirely removed by the cold rolling and heat treatment, led to a wide range of fracture modes of the axisymmetric samples. The failure strain was markedly lower for the cast and homogenised

  4. A hybrid aluminium alloy and its zoo of interacting nano-precipitates

    Wenner, Sigurd, E-mail: sigurd.wenner@ntnu.no [Department of Physics, NTNU, Høgskoleringen 5, NO-7491 Trondheim (Norway); Marioara, Calin Daniel; Andersen, Sigmund Jarle [Materials and Chemistry, SINTEF, Høgskoleringen 5, NO-7491 Trondheim (Norway); Ervik, Martin; Holmestad, Randi [Department of Physics, NTNU, Høgskoleringen 5, NO-7491 Trondheim (Norway)

    2015-08-15

    An alloy with aluminium as its base element is heat treated to form a multitude of precipitate phases known from different classes of industrial alloys: Al–Cu(–Mg), Al–Mg–Si–Cu, and Al–Zn–Mg. Nanometer-sized needle-shaped particles define the starting point of the phase nucleation, after which there is a split in the precipitation sequence into six phases of highly diverse compositions and morphologies. There are several unique effects of phases from different alloy systems being present in the same host lattice, of which we concentrate on two: the replacement of Ag by Zn on the Ω interface and the formation of combined plates of the θ′ and C phases. Using atomically resolved scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy, we investigate the formation mechanisms, crystal structures and compositions of the precipitates. - Graphical abstract: Display Omitted - Highlights: • An aluminium alloy composition in-between the 2/6/7xxx systems was investigated. • Six different phases from the three systems coexist in an over-aged state. • All phases with 〈001〉{sub Al} coherencies can nucleate on 6xxx needle precipitates. • Modified theta′ and omega interfaces are observed.

  5. Mould Filling Ability Characterisation of Cast Aluminium Alloys Using Design of Experiments

    Samavedam Santhi

    2012-01-01

    Full Text Available Mould filling ability characteristic has been influencing the liquid metal flow, heat transfer, and solidification there by affecting the quality of aerospace castings. Mould filling is a critical parameter in the production of sound and quality castings, especially in the case of complex-shaped castings where section thickness is varying considerably. The mould filling ability of aluminium alloys LM6 and LM25 has been studied in the present investigation. Experimentation has been carried out using orthogonal array experimental layout. The process parameters studied in the present investigation are alloy composition, sand fineness, mould coating, and pouring temperature. The mould filling ability of selected aluminium alloy has been studied using pin test piece with cylindrical cores. The results from experimentation are analyzed to find the influence of the process parameters on mould filling ability. Based on the above, LM6 alloy has been found to have better mould filling ability characteristics and the analysis of variance has also revealed the same optimum factor combination.

  6. A hybrid aluminium alloy and its zoo of interacting nano-precipitates

    An alloy with aluminium as its base element is heat treated to form a multitude of precipitate phases known from different classes of industrial alloys: Al–Cu(–Mg), Al–Mg–Si–Cu, and Al–Zn–Mg. Nanometer-sized needle-shaped particles define the starting point of the phase nucleation, after which there is a split in the precipitation sequence into six phases of highly diverse compositions and morphologies. There are several unique effects of phases from different alloy systems being present in the same host lattice, of which we concentrate on two: the replacement of Ag by Zn on the Ω interface and the formation of combined plates of the θ′ and C phases. Using atomically resolved scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy, we investigate the formation mechanisms, crystal structures and compositions of the precipitates. - Graphical abstract: Display Omitted - Highlights: • An aluminium alloy composition in-between the 2/6/7xxx systems was investigated. • Six different phases from the three systems coexist in an over-aged state. • All phases with 〈001〉Al coherencies can nucleate on 6xxx needle precipitates. • Modified theta′ and omega interfaces are observed

  7. The surface tension of liquid aluminium-based alloys

    In a systematic study, the surface tensions of the binary alloys Al-Fe and Al-Ni were investigated over a wide temperature and concentration range using electromagnetic levitation and the oscillating drop technique. Surface tensions were derived from the oscillation frequencies applying the formalism of Cummings and Blackburn. Temperature was measured by single-color pyrometry. Of particular interest in these alloys are melts corresponding to compositions of intermetallic phases, because potential ordering phenomena may influence all thermophysical properties. In both systems, an increase of the surface tension is observed at such concentrations. On the basis of partial excess Gibbs enthalpies, surface tensions can be calculated via the Butler equation and compared with experimental results. The agreement with our experimental data depends crucially on the quality of the thermodynamic potentials used. In addition, phenomenological models are also discussed, which describe the general trend correctly

  8. Precipitation in an AA6111 aluminium alloy and cosmetic corrosion

    Liu, Y. [Corrosion and Protection Centre, School of Materials, University of Manchester, Manchester M60 1QD (United Kingdom); Zhou, X. [Corrosion and Protection Centre, School of Materials, University of Manchester, Manchester M60 1QD (United Kingdom)]. E-mail: xiaorong.zhou@manchester.ac.uk; Thompson, G.E. [Corrosion and Protection Centre, School of Materials, University of Manchester, Manchester M60 1QD (United Kingdom); Hashimoto, T. [Corrosion and Protection Centre, School of Materials, University of Manchester, Manchester M60 1QD (United Kingdom); Scamans, G.M. [Innoval Technology, Beaumont Close, Banbury, Oxon OX16 1TQ (United Kingdom); Afseth, A. [Novelis Technology and Management, 8212 Neuhausen (Switzerland)

    2007-01-15

    The near-surface deformed layer on AA6111 automotive closure sheet alloy, generated by mechanical grinding during rectification, has an ultrafine grain microstructure, of 50-150 nm diameter, and a sharp transition with the underlying bulk alloy microstructure. Grinding and heat treatment to simulate rectification and paint baking processes result in the nucleation and growth of {approx}20 nm diameter precipitates at grain boundaries within the near-surface deformed layer. High-resolution transmission electron microscopy has shown Q phase precipitates in the deformed layer, giving dramatically increased corrosion susceptibility compared with the bulk microstructure, and this is responsible for the rapid-onset filiform corrosion. Transmission electron microscopy of the corrosion attack showed directly that the mode of corrosion was intergranular and that the Q phase precipitates were preserved after the passage of the corrosion front.

  9. Dilatometer study of rapidly solidified aluminium-silicon based alloys

    Varga, B [University TRANSILVANIA, B-dul Eroilor nr. 29, 500036, Brasov (Romania); Fazakas, E; Hargitai, H [Inst. for Materials Science and Technology, Bay Z. Foundation, Fehervari ut, 130., H-1116 Budapest (Hungary); Varga, L K, E-mail: varga@szfki.h

    2009-01-01

    Aluminum-Silicon alloys are sought in a large number of automotive and aerospace applications due to their low coefficient of thermal expansion and high wear resistance. The present study focused on structural transformations as a function of the temperature of rapidly solidified hypereutectic Al{sub 100-x}Si{sub x} (x = 12, 22 and 40) alloys. Different structures out of equilibrium have been obtained after casting in sand, graphite and copper moulds and by melt spinning. The retained Si content in supersaturated alpha Al and the precipitation of Si is discussed in the light of the dilatometer studies [1, 2, 3] complemented by metallographic microscopy, XRD and DSC [4] measurements. A Kissinger analysis was used to determine the activation energy for the precipitation of supersaturated Si content.

  10. Precipitation in an AA6111 aluminium alloy and cosmetic corrosion

    The near-surface deformed layer on AA6111 automotive closure sheet alloy, generated by mechanical grinding during rectification, has an ultrafine grain microstructure, of 50-150 nm diameter, and a sharp transition with the underlying bulk alloy microstructure. Grinding and heat treatment to simulate rectification and paint baking processes result in the nucleation and growth of ∼20 nm diameter precipitates at grain boundaries within the near-surface deformed layer. High-resolution transmission electron microscopy has shown Q phase precipitates in the deformed layer, giving dramatically increased corrosion susceptibility compared with the bulk microstructure, and this is responsible for the rapid-onset filiform corrosion. Transmission electron microscopy of the corrosion attack showed directly that the mode of corrosion was intergranular and that the Q phase precipitates were preserved after the passage of the corrosion front