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Sample records for reinforced aluminium alloy

  1. Fatigue properties of particle reinforced aluminium alloys

    International Nuclear Information System (INIS)

    Tabernig, B.J.

    2000-06-01

    In this work the particle reinforced Al-alloys 359 T6 + 20 % SiC and 2124 + 17 % SiC which differ significantly in their production and microstructure are investigated. Standard and in-situ tensile tests show, that in the powder metallurgically produced alloy 2124 reinforcement leads to a higher Young's modulus, yield and ultimate tensile stress where the cast alloy 359 + 20 % SiC exhibit increased stiffness, but low ductility due to cast porosity of some 100 μm. The failure mechanism governed by microstructural parameters is found to play an important role for ductility. The fatigue properties are investigated with specific regard to the influence of the in-service condition (load ratio, temperature, variable amplitude loading) in the foreseen applications in the automobile- and aerospace industry. Standard fatigue tests point out that the endurance limit is improved by reinforcement, but is strongly dependent on the size of given initial defects. The fatigue crack properties are characterised by standard crack growth curves and r(esistance)-curves for the threshold of stress intensity factor range. Both composites exhibit a higher effective threshold than their unreinforced alloys. Furthermore the fatigue resistance described by the R-curve as well as the long crack threshold are improved in the alloy 2124 + 17 % SiC. While in crack growth tests under constant amplitude loading the alloy 2124 + 17 % SiC shows lower crack growth rates than its unreinforced alloy, the opposite case is in the alloy 359 + 20 % SiC at high DK. Periodic overloads lead in the 359 + 20 % SiC to particle fracture at the crack tip and to a steeper increase in the crack growth rate. In the 2124 + 17% SiC the fatigue crack grows predominately in the matrix and a retardation effect due to overloads is observed. In order to describe the fatigue limit of components as a function of initial defect size an analytical concept is developed assuming that the fatigue limit is controlled by the

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

    Science.gov (United States)

    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.

  3. Ballistic impact velocity response of carbon fibre reinforced aluminium alloy laminates for aero-engine

    Science.gov (United States)

    Mohammed, I.; Abu Talib, A. R.; Sultan, M. T. H.; Saadon, S.

    2017-12-01

    Aerospace and other industries use fibre metal laminate composites extensively due to their high specific strength, stiffness and fire resistance, in addition to their capability to be tailored into different forms for specific purposes. The behaviours of such composites under impact loading is another factor to be considered due to the impacts that occur in take-off, landing, during maintenance and operations. The aim of the study is to determine the specific perforation energy and impact strength of the fibre metal laminates of different layering pattern of carbon fibre reinforced aluminium alloy and hybrid laminate composites of carbon fibre and natural fibres (kenaf and flax). The composites are fabricated using the hand lay-up method in a mould with high bonding polymer matrix and compressed by a compression machine, cured at room temperature for one day and post cure in an oven for three hours. The impact tests are conducted using a gun tunnel system with a flat cylindrical bullet fired using a helium gas at a distance of 14 inches to the target. Impact and residual velocity of the projectile are recorded by high speed video camera. Specific perforation energy of carbon fibre reinforced aluminium alloy (CF+AA) for both before and after fire test are higher than the specific perforation energy of the other composites considered before and after fire test respectively. CF +AA before fire test is 55.18% greater than after. The same thing applies to impact strength of the composites where CF +AA before the fire test has the highest percentage of 11.7%, 50.0% and 32.98% as respectively compared to carbon fibre reinforced aluminium alloy (CARALL), carbon fibre reinforced flax aluminium alloy (CAFRALL) and carbon fibre reinforced kenaf aluminium alloy (CAKRALL), and likewise for the composites after fire test. The considered composites in this test can be used in the designated fire zone of an aircraft engine to protect external debris from penetrating the engine

  4. Investigation of Selective Laser Melting Surface Alloyed Aluminium Metal Matrix Dispersive Reinforced Layers

    Science.gov (United States)

    Kamburov, V. V.; Dimitrova, R. B.; Kandeva, M. K.; Sofronov, Y. P.

    2018-01-01

    The aim of the paper is to investigate the improvement of mechanical properties and in particular wear resistance of laser surface alloyed dispersive reinforced thin layers produced by selective laser melting (SLM) technology. The wear resistance investigation of aluminium matrix composite layers in the conditions of dry friction surface with abrasive particles and nanoindentation tests were carried out. The process parameters (as scan speed) and their impact on the wear resistant layers have been evaluated. The alloyed layers containing metalized SiC particles were studied by Optical and Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray microanalysis (EDX). The obtained experimental results of the laser alloyed thin layers show significant development of their wear resistance and nanohardness due to the incorporated reinforced phase of electroless nickel coated SiC particles.

  5. Effect of Lubrication on Sliding Wear of Red Mud Particulate Reinforced Aluminium Alloy 6061

    Directory of Open Access Journals (Sweden)

    N. Panwar

    2017-09-01

    Full Text Available In present study, Red mud, an industrial waste, has been utilized as a reinforcement material to fabricate Aluminium 6061 matrix based metal matrix composite. Taguchi L18 orthogonal array has been employed for fabrication of composite castings and for conducting the tribological experimentation. ANOVA analysis has been applied to examine the effect of individual parameters such as sliding condition: dry and wet, reinforcement weight fraction, load, speed, and sliding distance on specific wear rate obtained experimentally. It has been found that tensile strength and impact energy increases while elongation decreases, with increasing weight fraction and decrease in particle size of red mud. The percentage contribution of the effect of factors on SWR is Sliding condition (73.17, speed (7.84, percentage reinforcement (7.35, load (5.75, sliding distance (2.24, and particle size (1.25. It has also been observed that specific wear rate is very low in wet condition. However, it decreases with increase in weight fraction of reinforcement, decrease in load and sliding speed. Al6061/red mud metal matrix composites have shown reasonable strength and wear resistance. The use of red mud in Aluminium composite provides the solution for disposal of red mud and can possibly become an economic replacement of Aluminium and its alloys.

  6. Numerical modelling in friction lap joining of aluminium alloy and carbon-fiber-reinforced-plastic sheets

    Science.gov (United States)

    Das, A.; Bang, H. S.; Bang, H. S.

    2018-05-01

    Multi-material combinations of aluminium alloy and carbon-fiber-reinforced-plastics (CFRP) have gained attention in automotive and aerospace industries to enhance fuel efficiency and strength-to-weight ratio of components. Various limitations of laser beam welding, adhesive bonding and mechanical fasteners make these processes inefficient to join metal and CFRP sheets. Friction lap joining is an alternative choice for the same. Comprehensive studies in friction lap joining of aluminium to CFRP sheets are essential and scare in the literature. The present work reports a combined theoretical and experimental study in joining of AA5052 and CFRP sheets using friction lap joining process. A three-dimensional finite element based heat transfer model is developed to compute the temperature fields and thermal cycles. The computed results are validated extensively with the corresponding experimentally measured results.

  7. Aluminium EN AW-2124 alloy matrix composites reinforced with Ti(C,N), BN and Al2O3 particles

    International Nuclear Information System (INIS)

    Dobrzanski, L.A.; Wlodarczyk, A.; Adamiak, M.

    2003-01-01

    Investigation results of the aluminium alloy EN AW-2124 matrix composite materials with particles of the powders Ti(C,N), BN and Al 2 O 3 (15 wt.%) are presented in the paper. In order to obtain uniform distribution of reinforcement particles in aluminium alloy matrix powders of composite components have been milled in the rotary ball-bearing pulverizer. The composites have been pressed in laboratory vertical press at room temperature under the pressure of 500 kN. Obtained die samplings have been heated to the temperature 520-550 o C and extruded. Bars of diameter 8 mm have been received as a final product. Metallographic examination of the composites materials' structure shows non-uniform distribution of reinforced powders in the aluminium alloy matrix banding of reinforcements particles corresponds to the extrusion direction. Particles of reinforcement distribution in aluminium alloy matrix is irregular, some agglomerations of powder of aluminium oxide and porosity of different size have been noticed. Investigations of hardness and ultimate compressive strength show that the particles of reinforcement improve mechanical properties of composite materials. Investigations of compressive strength, carried out at room temperature, enable to compare mechanical properties of matrix and composite. (author)

  8. Mechanical spectroscopy of thermal stress relaxation in aluminium alloys reinforced with short alumina fibres

    Energy Technology Data Exchange (ETDEWEB)

    Carreno-Morelli, E.; Schaller, R. [Ecole Polytechnique Federale, Lausanne (Switzerland). Inst. de Genie Atomique; Urreta, S.E.

    1998-05-01

    The mechanical behaviour under low temperature thermal cycling of aluminium-based composites reinforced with short Al{sub 2}O{sub 3} SAFFIL fibres has been investigated by mechanical spectroscopy (mechanical loss and elastic shear modulus measurements). A mechanical loss maximum has been observed during cooling which originates in the relaxation of thermal stresses at the interfaces due to the differential thermal expansion between matrix and reinforcement. The maximum height increases with the volumetric fibre content. In addition, if the matrix strength is increased by the appropriated choice of alloy and thermal treatment, the maximum diminishes and shifts to lower temperatures. No damage accumulation at the interfaces has been detected during long period thermal cycling in the range 100 to 500 K. A description of the damping behaviour is made in terms of the development of microplastic zones which surround the fibres. (orig.) 9 refs.

  9. Microstructural characterization of fly ash particulate reinforced AA6063 aluminium alloy for aerospace applications

    Science.gov (United States)

    Razzaq, A. M.; Majid, D. L. Abang Abdul; Ishak, M. R.; Uday, M. B.

    2017-12-01

    Aluminium-fly ash (FA) particulate reinforced composites (AA6063-FA) have been used in automotive and aerospace industries because of their low density and good mechanical properties. Three different weight fraction of FA: 2%, 4% and 6% are added to AA6063 alloy using compocasting method. The effect of FA particulates on microstructure, density and compression strength of AA6063- FA composites are investigated. Field Emission Scanning Electron Microscope (FESEM) micrographs reveal that the FA particulates are uniformly distributed in AA6063 alloy. The results also show that density, compression strength and microstructure of the AA6063-FA composites are significantly influenced by the FA amount. The increase in the weight fraction of FA will improve the microstructure and enhance the compression strength. The density of AA6063-FA composites decreases as the incorporation of FA increases.

  10. Wear behaviour of A356 aluminium alloy reinforced with micron and nano size SiC particles

    CSIR Research Space (South Africa)

    Camagu, ST

    2013-07-01

    Full Text Available A method for producing metal matrix composites MMC was successfully implemented for mixing nano and low micron (“Hybrid”) sized SiC reinforcing particles in an aluminium alloy matrix. Due to the improved specific modulus and strength, MMC...

  11. Evaluation of Mechanical Properties of MWCNT / Nanoclay Reinforced Aluminium alloy Metal Matrix Composite

    Science.gov (United States)

    Ratna Kumar, P. S. Samuel; Robinson Smart, D. S.; Alexis, S. John

    2018-04-01

    Aluminium alloy 5083 (AA5083) is a widely used material in aerospace, marine, defence and structural applications were mechanical and corrosion resistance property plays a vital role. For the present work, MWCNT / Nanoclay (montmorillonite (MMT) K10) mixed with AA5083 for different composition in weight percentage to enhance the mechanical property. Semi-solid state casting method (Compo-casting) was used to fabricate the composite materials. By using Field-emission scanning electron microscope (FESEM) the uniform dispersion of the reinforcement and microstructure were studied. Finally, the addition of Nanoclay shows decrease in tensile strength compared to the AA5083 / MWCNT composites and hardness value of the composites (AA5083 / MWCNT and AA5083 / Nanoclay) was found to increase significantly.

  12. Effect of Lubrication on Sliding Wear of Red Mud Particulate Reinforced Aluminium Alloy 6061

    OpenAIRE

    N. Panwar; R.P. Poonia; G. Singh; R. Dabral; A. Chauhan

    2017-01-01

    In present study, Red mud, an industrial waste, has been utilized as a reinforcement material to fabricate Aluminium 6061 matrix based metal matrix composite. Taguchi L18 orthogonal array has been employed for fabrication of composite castings and for conducting the tribological experimentation. ANOVA analysis has been applied to examine the effect of individual parameters such as sliding condition: dry and wet, reinforcement weight fraction, load, speed, and sliding distance on specific wear...

  13. Diffusion bonding of an aluminium alloy (AA 2124) reinforced with SiC whiskers, using AL-Li interlayers (AA 8090)

    International Nuclear Information System (INIS)

    Urena, A.; Gomez de Salazar, J.M.; Escalera, M.D.; Escriche, E.

    1994-01-01

    The use of an AL-Li alloy as interlayer for the diffusion bonding of an aluminium matrix composite reinforced with silicon carbide whiskers has been studied. The influence of the different welding parameters on the joint microstructure and mechanical strength has also been analyzed. Besides, the failure mechanisms of shear tested joints have been investigated using fractographic techniques. (Author) 9 refs

  14. Laser welding of aluminium alloys

    OpenAIRE

    Forsman, Tomas

    2000-01-01

    This thesis treats laser welding of aluminium alloys from a practical perspective with elements of mathematical analysis. The theoretical work has in all cases been verified experimentally. The aluminium alloys studied are from the 5xxx and 6xxx groups which are common for example in the automotive industry. Aluminium has many unique physical properties. The properties which more than others have been shown to influence the welding process is its high reflection, high thermal conductivity, lo...

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

    Directory of Open Access Journals (Sweden)

    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

  16. Silicon Alloying On Aluminium Based Alloy Surface

    International Nuclear Information System (INIS)

    Suryanto

    2002-01-01

    Silicon alloying on surface of aluminium based alloy was carried out using electron beam. This is performed in order to enhance tribological properties of the alloy. Silicon is considered most important alloying element in aluminium alloy, particularly for tribological components. Prior to silicon alloying. aluminium substrate were painted with binder and silicon powder and dried in a furnace. Silicon alloying were carried out in a vacuum chamber. The Silicon alloyed materials were assessed using some techniques. The results show that silicon alloying formed a composite metal-non metal system in which silicon particles are dispersed in the alloyed layer. Silicon content in the alloyed layer is about 40% while in other place is only 10.5 %. The hardness of layer changes significantly. The wear properties of the alloying alloys increase. Silicon surface alloying also reduced the coefficient of friction for sliding against a hardened steel counter face, which could otherwise be higher because of the strong adhesion of aluminium to steel. The hardness of the silicon surface alloyed material dropped when it underwent a heating cycle similar to the ion coating process. Hence, silicon alloying is not a suitable choice for use as an intermediate layer for duplex treatment

  17. Three body abrasion of laser surface alloyed aluminium AA1200

    CSIR Research Space (South Africa)

    Mabhali, Luyolo AB

    2012-06-01

    Full Text Available Laser surface alloying of aluminium AA1200 was performed with a 4 kW Nd:YAG laser to improve the abrasion wear resistance. Aluminium surfaces reinforced with metal matrix composites and intermetallic phases were achieved. The phases present depended...

  18. Hot workability of aluminium alloys

    International Nuclear Information System (INIS)

    Yoo, Yeon Chul; Oh, Kyung Jin

    1986-01-01

    Hot Workability of aluminium alloys, 2024, 6061 and 7075, has been studied by hot torsion tests at temperatures from 320 to 515 deg C and at strain rates from 1.26 x 10 -3 to 5.71 x 10 -3 sec -1 . Hot working condition of these aluminium alloys was determined quantitatively from the constitutive equations obtained from flow stress curves in torsion. Experimental data of the logarith of the Zener-Hollomonn parameter showed good linear relationships to the logarith of sinh(ασ-bar)

  19. Recent developments in advanced aircraft aluminium alloys

    International Nuclear Information System (INIS)

    Dursun, Tolga; Soutis, Costas

    2014-01-01

    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. Effect of Welding Speed on Microstructure and Mechanical Properties due to The Deposition of Reinforcements on Friction Stir Welded Dissimilar Aluminium Alloys

    Directory of Open Access Journals (Sweden)

    Baridula Ravinder Reddy

    2017-01-01

    Full Text Available The strength of the welded joint obtained by solid state stir welding process was found to be improved as compared to fusion welding process. The deposition of reinforcements during friction stir welding process can further enhance the strength of the welded joint by locking the movement of grain boundaries. In the present study, the aluminium alloys AA2024 and AA7075 were welded effectively by depositing the multi-walled carbon nanotubes in to the stir zone. The mechanical properties and microstructures were studied by varying the traverse speed at constant rotational speed. The results show that rotating tool pin stirring action and heat input play an important role in controlling the grain size. The carbon nanotubes were found to be distributed uniformly at a welding speed (traverse speed of 80mm/min. This enhanced the mechanical properties of the welded joint. The microstructure and Electron dispersive X-ray analysis (EDX studies indicate that the deposition of carbon nanotubes in the stir zone was influenced by the traverse speed.

  1. Irradiation effects in magnesium and aluminium alloys

    International Nuclear Information System (INIS)

    Sturcken, E.F.

    1979-01-01

    Effects of neutron irradiation on microstructure, mechanical properties and swelling of several magnesium and aluminium alloys were studied. The neutron fluences of 2-3 X 10 22 n/cm 2 , >0.2 MeV produced displacement doses of 20 to 45 displacements per atom (dpa). Ductility of the magnesium alloys was severely reduced by irradiation induced recrystallization and precipitation of various forms. Precipitation of transmuted silicon occurred in the aluminium alloys. However, the effect on ductility was much less than for the magnesium alloys. The magnesium and aluminium alloys had excellent resistance to swelling: The best magnesium alloy was Mg/3.0 wt% Al/0.19 wt% Ca; its density decreased by only 0.13%. The best aluminium alloy was 6063, with a density decrease of 0.22%. (Auth.)

  2. Surface treatments for aluminium alloys

    Science.gov (United States)

    Ardelean, M.; Lascău, S.; Ardelean, E.; Josan, A.

    2018-01-01

    Typically, in contact with the atmosphere, the aluminium surface is covered with an aluminium oxide layer, with a thickness of less than 1-2μm. Due to its low thickness, high porosity and low mechanical strength, this layer does not protect the metal from corrosion. Anodizing for protective and decorative purposes is the most common method of superficial oxidation processes and is carried out through anodic oxidation. The oxide films, resulted from anodizing, are porous, have a thickness of 20-50μm, and are heat-resistant, stable to water vapour and other corrosion agents. Hard anodizing complies with the same obtains principles as well as decorative and protective anodization. The difference is in that hard anodizing is achieved at low temperatures and high intensity of electric current. In the paper are presented the results of decorative and hard anodization for specimens made from several aluminium alloys in terms of the appearance of the specimens and of the thickness of the anodized.

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

    DEFF Research Database (Denmark)

    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...

  4. Characterization of aluminium alloys rapidly solidified

    International Nuclear Information System (INIS)

    Monteiro, W.A.

    1988-01-01

    This paper discussed the investigation of the microstructural and mechanical properties of the aluminium alloys (3003; 7050; Al-9% Mg) rapidly solidified by melt spinning process (cooling rate 10 4 - 10 6 K/s). The rapidly solidification process of the studied aluminium alloys brought a microcrystallinity, a minimum presence of coarse precipitation and, also, better mechanical properties of them comparing to the same alloys using ingot process. (author) [pt

  5. Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders

    NARCIS (Netherlands)

    De Kanter, J.L.C.G.

    2006-01-01

    Summary accompanying the thesis: Energy Absorption of Monolithic and Fibre Reinforced Aluminium Cylinders by Jens de Kanter This thesis presents the investigation of the crush behaviour of both monolithic aluminium cylinders and externally fibre reinforced aluminium cylinders. The research is based

  6. Alloys of uranium and aluminium with low aluminium content

    International Nuclear Information System (INIS)

    Cabane, G.; Englander, M.; Lehmann, J.

    1955-01-01

    Uranium, as obtained after spinning in phase γ, presents an heterogeneous structure with large size grains. The anisotropic structure of the metal leads to an important buckling and surface distortion of the fuel slug which is incompatible with its tubular cladding for nuclear fuel uses. Different treatments have been made to obtain an isotropic structure presenting high thermal stability (laminating, hammering and spinning in phase α) without success. Alloys of uranium and aluminium with low aluminium content present important advantage in respect of non allied uranium. The introduction of aluminium in the form of intermetallic compound (UAl 2 ) gives a better resistance to thermal fatigue. Alloys obtained from raw casting present an improved buckling and surface distortion in respect of pure uranium. This improvement is obtained with uranium containing between 0,15 and 0,5 % of aluminium. An even more improvement in thermal stability is obtained by thermal treatments of these alloys. These new characteristics are explained by the fine dispersion of the UAl 2 particles in uranium. The results after treatments obtained from an alloy slug containing 0,4 % of aluminium show no buckling or surface distortion and no elongation. (M.P.)

  7. Mechanical behaviour of aluminium-lithium alloys

    Indian Academy of Sciences (India)

    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 ...

  8. Developing connectivity of the phases in a short fibre reinforced aluminium piston alloy subjected to creep; Entwicklung der Konnektivitaet der Phasen in einer kurzfaserverstaerkten Aluminium-Kolbenlegierung unter Kriechbelastung

    Energy Technology Data Exchange (ETDEWEB)

    Requena, G.C.; Degischer, H.P.; Marks, E.D. [Institute of Materials Science and Technology, Vienna University of Technology, Karlsplatz 13/308 - A1040 Vienna (Australia); Boller, E. [European Synchrotron Radiation Facility (France)

    2007-11-15

    The evolution of the micro-structure during creep of an AlSi12CuMgNi piston alloy with 15 vol% of Al{sub 2}O{sub 3} short fibres is investigated by means of synchrotron micro-tomography. The results reveal a 3D morphology of the rigid phases in the composite: the eutectic-Si, the short fibres and the Fe- and Ni-rich intermetallic particles, which form an interconnected hybrid reinforcement. The connectivity of these phases increases during creep exposure at 300 C due to the diffusion induced ripening of Si and of the intermetallic particles. The hybrid reinforcement reaches almost complete percolation after 6400 h of creep exposure. The fibre orientation analysed by three-dimensional Fast Fourier Transformation does not indicate any reorientation of the fibres along the load direction. The formerly observed strengthening effect during creep exposure is attributed to the increasing load carrying capacity of the interconnected hybrid reinforcement. The analysis of creep damage during secondary creep stage shows the increase of the void volume fraction by a factor of 2 with respect to the void content from processing, while the number of voids per volume remains practically constant. The voids are located at interfaces of the rigid phases and not within the {alpha}-aluminium matrix. (Abstract Copyright [2007], Wiley Periodicals, Inc.) [German] Das drei-dimensionale Gefuege einer AlSi12CuMgNi-Kolbenlegierung verstaerkt mit 15 vol% Al{sub 2}O{sub 3}-Kurzfasern wird mittels Synchrotron Mikro-Tomographie dargestellt. Der loesungsgegluehte Ausgangszustand enthaelt ein zusammenhaengendes Netzwerk aus Kurzfasern und Fe- und Ni-reichen Primaerausscheidungen, das darueber hinaus durch eine Vielzahl von Si-Bruecken des Eutektikums verbunden wird. Die Konnektivitaet nimmt mit der Dauer der Kriechbelastung bei 300 C zu, besonders durch die Reifung der Si-Teilchen, die zu einer in sich zusammenhaengenden Struktur zusammenwachsen, die mit dem bereits vorhandenen Netzwerk mit den

  9. Corrosion characterization of in-situ titanium diboride (TiB2) reinforced aluminium-copper (Al-Cu) alloy by two methods: Salts spray fog and linear polarization resistance (LPR)

    Science.gov (United States)

    Rosmamuhamadani, R.; Talari, M. K.; Yahaya, Sabrina M.; Sulaiman, S.; Ismail, M. I. S.; Hanim, M. A. Azmah

    2018-05-01

    Aluminium-copper (Al-Cu) alloys is the one of most Metal Matrix Composites (MMCs) have important high-strength Al alloys. The aluminium (Al) casting alloys, based on the Al-Cu system are widely used in light-weight constructions and transport applications requiring a combination of high strength and ductility. In this research, Al-Cu master alloy was reinforced with 3 and 6wt.% titanium diboride (TiB2) that obtained from salts route reactions. The salts used were were potassium hexafluorotitanate (K2TiF6) and potassium tetrafluoroborate (KBF4). The salts route reaction process were done at 800 °C. The Al-Cu alloy then has characterized on the mechanical properties and microstructure characterization. Salts spray fog test and Gamry-electrode potentiometer instruments were used to determine the corrosion rate of this alloys. From results obtained, the increasement of 3wt.%TiB2 contents will decrease the value of the corrosion rate. In corrosion test that conducted both of salt spray fog and Gamry-electrode potentiometer, the addition of 3wt.%TiB2 gave the good properties in corrosion characterization compare to Al-Cu-6wt.%TiB2 and Al-Cu cast alloy itself. As a comparison, Al-Cu with 3wt.%TiB2 gave the lowest value of corrosion rate, which means alloy has good properties in corrosion characterization. The results obtained show that in-situ Al-Cu alloy composites containing the different weight of TiB2 phase were synthesized successfully by the salt-metal reaction method.

  10. Steam generated conversion coating on aluminium alloys

    DEFF Research Database (Denmark)

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

    Aluminium and its alloys are widely used in aerospace industry owing to their high strength to weight ratio. The surface of aluminium under normal conditions has a thin oxide film (2.5-10 nm) responsible for its inherent corrosion resistance. This oxide film can further be 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 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 aluminium oxide (γ-AlO(OH) , Al(OH)3...

  11. Steam Initiated Surface Modification of Aluminium Alloys

    DEFF Research Database (Denmark)

    Din, Rameez Ud

    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...... the use of aluminium alloys in the painted form requiring a conversion coating to improve the adhesion. Chromate based conversion coating processes are extremely good for these purposes, however the carcinogenic and toxic nature of hexavalent chromium led to the search for more benign and eco......, crystalline nano-particles, role of steam-based treatment on adhesion of industrially applied powder coating, and investigations of a failed painted aluminium window profile due to defects in the extruded profile. Chapters 13 and 14 describe the overall discussion, conclusions and future work based...

  12. Mechanical properties of aluminium matrix composites reinforced with intermetallics

    International Nuclear Information System (INIS)

    Torres, B.; Garcia-Escorial, A.; Ibanez, J.; Lieblich, M.

    2001-01-01

    In this work 2124 aluminium matrix composites reinforced with Ni 3 Al, NiAl, MoSi 2 and Cr 3 Si intermetallic powder particles have been investigated. For comparison purposes, un reinforced 2124 and reinforced with SiC have also been studied. In all cases, the same powder metallurgy route was used, i. e. the 2124 alloy was obtained by rapid solidification and the intermetallic particles by self-propagating high-temperature synthesis (SHS). The matrix and the intermetallics were mechanically blended, cold compacted and finally hot extruded. Tensile tests were carried out in T1 and T4 treatments. Results indicate that mechanical properties depend strongly on the tendency to form new phases at the matrix-intermetallic interface during processing and/or further thermal treatments. The materials which present better properties are those that present less reaction between matrix and intermetallic reinforcement, i. e. MoSi 2 and SiC reinforced composites. (Author) 9 refs

  13. Impact toughness of laser alloyed aluminium AA1200 alloys

    CSIR Research Space (South Africa)

    Mabhali, Luyolo AB

    2013-08-01

    Full Text Available ),. 559-563. [2] T. Tomida, K. Nakata, S. Saji, T. Kubo, T, Formation of metal matrix composite layer on aluminium alloy with TiC-Cu powder by laser surface alloying process; Surface and Coatings Technology; vol. 142-144, 2001, 585-589. [3] L. A. B...

  14. Friction Welding of Aluminium and Aluminium Alloys with Steel

    Directory of Open Access Journals (Sweden)

    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.

  15. Argon-arc welding of heat resisting aluminium alloys

    International Nuclear Information System (INIS)

    Ryazantsev, V.I.; Fedoseev, V.A.

    1997-01-01

    Welding of aluminium heat resisting alloys of the Al-Cu-Mg system is studied. The hot-shortness of heat-resistant alloys M40, 1150 and 1151 are at the level of aluminium alloys 1201 and by 2-3 times lower as compared to the aluminium alloy AMg6. The M40, 1150 and 1151 alloys have unquestionable advantages against other know aluminium alloys only at temperatures of welded structures operation, beginning with 150-2000 deg C and especially at 250 deg C

  16. Grain distinct stratified nanolayers in aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Donatus, U., E-mail: uyimedonatus@yahoo.com [School of Materials, The University of Manchester, Manchester, M13 9PL, England (United Kingdom); Thompson, G.E.; Zhou, X.; Alias, J. [School of Materials, The University of Manchester, Manchester, M13 9PL, England (United Kingdom); Tsai, I.-L. [Oxford Instruments NanoAnalysis, HP12 2SE, High Wycombe (United Kingdom)

    2017-02-15

    The grains of aluminium alloys have stratified nanolayers which determine their mechanical and chemical responses. In this study, the nanolayers were revealed in the grains of AA6082 (T6 and T7 conditions), AA5083-O and AA2024-T3 alloys by etching the alloys in a solution comprising 20 g Cr{sub 2}O{sub 3} + 30 ml HPO{sub 3} in 1 L H{sub 2}O. Microstructural examination was conducted on selected grains of interest using scanning electron microscopy and electron backscatter diffraction technique. It was observed that the nanolayers are orientation dependent and are parallel to the {100} planes. They have ordered and repeated tunnel squares that are flawed at the sides which are aligned in the <100> directions. These flawed tunnel squares dictate the tunnelling corrosion morphology as well as appearing to have an affect on the arrangement and sizes of the precipitation hardening particles. The inclination of the stratified nanolayers, their interpacing, and the groove sizes have significant influence on the corrosion behaviour and seeming influence on the strengthening mechanism of the investigated aluminium alloys. - Highlights: • Stratified nanolayers in aluminium alloy grains. • Relationship of the stratified nanolayers with grain orientation. • Influence of the inclinations of the stratified nanolayers on corrosion. • Influence of the nanolayers interspacing and groove sizes on hardness and corrosion.

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

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Yuksel, Serkan; Jellesen, Morten Stendahl

    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....

  18. Alloys of uranium and aluminium with low aluminium content; Alliages uranium-aluminium a faible teneur en aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Cabane, G; Englander, M; Lehmann, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    Uranium, as obtained after spinning in phase {gamma}, presents an heterogeneous structure with large size grains. The anisotropic structure of the metal leads to an important buckling and surface distortion of the fuel slug which is incompatible with its tubular cladding for nuclear fuel uses. Different treatments have been made to obtain an isotropic structure presenting high thermal stability (laminating, hammering and spinning in phase {alpha}) without success. Alloys of uranium and aluminium with low aluminium content present important advantage in respect of non allied uranium. The introduction of aluminium in the form of intermetallic compound (UAl{sub 2}) gives a better resistance to thermal fatigue. Alloys obtained from raw casting present an improved buckling and surface distortion in respect of pure uranium. This improvement is obtained with uranium containing between 0,15 and 0,5 % of aluminium. An even more improvement in thermal stability is obtained by thermal treatments of these alloys. These new characteristics are explained by the fine dispersion of the UAl{sub 2} particles in uranium. The results after treatments obtained from an alloy slug containing 0,4 % of aluminium show no buckling or surface distortion and no elongation. (M.P.)

  19. Precipitate strengthening of nanostructured aluminium alloy.

    Science.gov (United States)

    Wawer, Kinga; Lewandowska, Malgorzata; Kurzydlowski, Krzysztof J

    2012-11-01

    Grain boundaries and precipitates are the major microstructural features influencing the mechanical properties of metals and alloys. Refinement of the grain size to the nanometre scale brings about a significant increase in the mechanical strength of the materials because of the increased number of grain boundaries which act as obstacles to sliding dislocations. A similar effect is obtained if nanoscale precipitates are uniformly distributed in coarse grained matrix. The development of nanograin sized alloys raises the important question of whether or not these two mechanisms are "additive" and precipitate strengthening is effective in nanostructured materials. In the reported work, hydrostatic extrusion (HE) was used to obtain nanostructured 7475 aluminium alloy. Nanosized precipitates were obtained by post-HE annealing. It was found that such annealing at the low temperatures (100 degrees C) results in a significant increase in the microhardness (HV0.2) and strength of the nanostructured 7475 aluminium alloy. These results are discussed in terms of the interplay between the precipitation and deformation of nanocrystalline metals.

  20. Aluminium alloys containing iron and nickel

    International Nuclear Information System (INIS)

    Coriou, H.; Fournier, R.; Grall, L.; Hure, J.; Herenguel, J.; Lelong, P.

    1958-01-01

    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)

  1. Solidification microstructures of aluminium-uranium alloys

    International Nuclear Information System (INIS)

    Ambrozio Filho, F.; Vieira, R.R.

    1976-01-01

    The solidification of microstrutures of aluminium-uranium alloys in the range of 4 to 20% uranium is investigated. The solidification was obtained both in ingot molds and under controlled directional solidification. The conditions for the presence of primary crystals and eutectic are discussed and an analysis of the influence of variables (growth rate and thermal gradient in the liquid) on the alloy structure is made. The effect of cooling rate on the alloy structures has been determined. It is found that the resulting structure can be derived from the kinectics concept, as required by the coupled-zone theory. Suggestions on the qualitative intervals of composition and temperatures with eutectic growth are presented [pt

  2. Aluminium/iron reinforced polyfurfuryl alcohol resin as advanced biocomposites

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2016-07-01

    Full Text Available Aluminium and iron are widely used in construction sectors for the preparation of advanced composites with epoxy resins as matrices. In recent times, there are several reports on the polymerization of polyfufuryl alcohol (PFA a thermoset bioresins from furfuryl alcohol (FA. FA is obtained from waste of sugarcane bagasse. In this work, first the possibility of curing PFA from FA in the presence of aluminium or iron has been explored. Absorbance results from colorimeter/spectrophotometerindicated that the curing of FA to PFA in presence of aluminium started easily while in presence of iron the curing of FA to PFA could not start. Based on the above results, aluminium wire reinforced composites were successfully prepared with three different weight fractions (0.13, 0.09 and 0.07 of aluminium wire. The mechanical properties of these composites were determined theoretically and reported.

  3. Combined Corrosion and Wear of Aluminium Alloy 7075-T6

    NARCIS (Netherlands)

    Liu, Y.; Mol, J.M.C.; Janssen, G.C.A.M.

    2016-01-01

    The aluminium alloy 7075-T6 is widely used in engineering. In some applications, like slurry transport, corrosion and abrasion occur simultaneously, resulting in early material failure. In the present work, we investigated the combined effect of corrosion and wear on the aluminium alloy 7075-T6. We

  4. Deviatoric response of the aluminium alloy, 5083

    Science.gov (United States)

    Appleby-Thomas, Gareth; Hazell, Paul; Millett, Jeremy; Bourne, Neil

    2009-06-01

    Aluminium alloys such as 5083 are established light weight armour materials. As such, the shock response of these materials is of great importance. The shear strength of a material under shock loading provides an insight into its ballistic performance. In this investigation embedded manganin stress gauges have been employed to measure both the longitudinal and lateral components of stress during plate impact experiments over a range of impact stresses. In turn, these results were used to determine the shear strength and to investigate the time dependence of lateral stress behind the shock front to give an indication of material response.

  5. TITANIUM CARBON ALUMINIUM : A NOVEL GRAIN REFINER FOR ALUMINIUM-LITHIUM ALLOYS

    OpenAIRE

    Birch , M.; Cowell , A.

    1987-01-01

    This work explores the possibility of achieving grain size control in aluminium-lithium alloys with the titanium carbon aluminium (TiCAl) master alloys invented at the Technical University of Berlin and developed by London and Scandinavian Metallurgical Co Ltd (LSM). Grain refining tests were conducted on a single batch of 8090 alloy using addition rates of 0.2wt% and 0.4wt% of TiCAl and 3/1 titanium boron aluminium (TiBAl). Other tests using 0.4wt% of binary TiAl gave poor results, showing t...

  6. Aluminium alloys in municipal solid waste incineration bottom ash.

    Science.gov (United States)

    Hu, Yanjun; Rem, Peter

    2009-05-01

    With the increasing growth of incineration of household waste, more and more aluminium is retained in municipal solid waste incinerator bottom ash. Therefore recycling of aluminium from bottom ash becomes increasingly important. Previous research suggests that aluminium from different sources is found in different size fractions resulting in different recycling rates. The purpose of this study was to develop analytical and sampling techniques to measure the particle size distribution of individual alloys in bottom ash. In particular, cast aluminium alloys were investigated. Based on the particle size distribution it was computed how well these alloys were recovered in a typical state-of-the-art treatment plant. Assessment of the cast alloy distribution was carried out by wet physical separation processes, as well as chemical methods, X-ray fluorescence analysis and electron microprobe analysis. The results from laboratory analyses showed that cast alloys tend to concentrate in the coarser fractions and therefore are better recovered in bottom ash treatment plants.

  7. Thermodynamic properties of uranium in gallium–aluminium based alloys

    International Nuclear Information System (INIS)

    Volkovich, V.A.; Maltsev, D.S.; Yamshchikov, L.F.; Chukin, A.V.; Smolenski, V.V.; Novoselova, A.V.; Osipenko, A.G.

    2015-01-01

    Activity, activity coefficients and solubility of uranium was determined in gallium-aluminium alloys containing 1.6 (eutectic), 5 and 20 wt.% aluminium. Additionally, activity of uranium was determined in aluminium and Ga–Al alloys containing 0.014–20 wt.% Al. Experiments were performed up to 1073 K. Intermetallic compounds formed in the alloys were characterized by X-ray diffraction. Partial and excess thermodynamic functions of U in the studied alloys were calculated. - Highlights: • Thermodynamics of uranium is determined in Ga–Al alloys of various compositions. • Uranium in the mixed alloys interacts with both components, Ga and Al. • Interaction of U with Al increases with decreasing temperature. • Activity and solubility of uranium depend on Al content in Ga–Al alloys.

  8. Thermodynamic properties of uranium in gallium–aluminium based alloys

    Energy Technology Data Exchange (ETDEWEB)

    Volkovich, V.A., E-mail: v.a.volkovich@urfu.ru [Department of Rare Metals and Nanomaterials, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Maltsev, D.S.; Yamshchikov, L.F. [Department of Rare Metals and Nanomaterials, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Chukin, A.V. [Department of Theoretical Physics and Applied Mathematics, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Smolenski, V.V.; Novoselova, A.V. [Institute of High-Temperature Electrochemistry UD RAS, Ekaterinburg, 620137 (Russian Federation); Osipenko, A.G. [JSC “State Scientific Centre - Research Institute of Atomic Reactors”, Dimitrovgrad, 433510 (Russian Federation)

    2015-10-15

    Activity, activity coefficients and solubility of uranium was determined in gallium-aluminium alloys containing 1.6 (eutectic), 5 and 20 wt.% aluminium. Additionally, activity of uranium was determined in aluminium and Ga–Al alloys containing 0.014–20 wt.% Al. Experiments were performed up to 1073 K. Intermetallic compounds formed in the alloys were characterized by X-ray diffraction. Partial and excess thermodynamic functions of U in the studied alloys were calculated. - Highlights: • Thermodynamics of uranium is determined in Ga–Al alloys of various compositions. • Uranium in the mixed alloys interacts with both components, Ga and Al. • Interaction of U with Al increases with decreasing temperature. • Activity and solubility of uranium depend on Al content in Ga–Al alloys.

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

    Indian Academy of Sciences (India)

    zinc alloys using ring compression test at different temperatures from 303 K to 773 K. It is found that CP aluminium exhibits stick- ing whereas Al–Zn alloys do not exhibit sticking at elevated temperatures. Hot working of Al–Zn alloy is easier.

  10. A Brief Research Review for Improvement Methods the Wettability between Ceramic Reinforcement Particulate and Aluminium Matrix Composites

    Science.gov (United States)

    Razzaq, Alaa Mohammed; Majid, Dayang Laila Abang Abdul; Ishak, M. R.; B, Uday M.

    2017-05-01

    The development of new methods for addition fine ceramic powders to Al aluminium alloy melts, which would lead to more uniform distribution and effective incorporation of the reinforcement particles into the aluminium matrix alloy. Recently the materials engineering research has moved to composite materials from monolithic, adapting to the global need for lightweight, low cost, quality, and high performance advanced materials. Among the different methods, stir casting is one of the simplest ways of making aluminium matrix composites. However, it suffers from poor distribution and combination of the reinforcement ceramic particles in the metal matrix. These problems become significantly effect to reduce reinforcement size, more agglomeration and tendency with less wettability for the ceramic particles in the melt process. Many researchers have carried out different studies on the wettability between the metal matrix and dispersion phase, which includes added wettability agents, fluxes, preheating the reinforcement particles, coating the reinforcement particles, and use composting techniques. The enhancement of wettability of ceramic particles by the molten matrix alloy and the reinforcement particles distribution improvement in the solidified matrix is the main objective for many studies that will be discussed in this paper.

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

    International Nuclear Information System (INIS)

    Hillairet, J.; Delaplace, J.; Silvent, A.

    1966-01-01

    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) [fr

  12. Adhesive Bonding of Aluminium Alloy A5754 by Epoxy Resins

    Directory of Open Access Journals (Sweden)

    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.

  13. Effect of iron and silicon in aluminium and its alloys

    International Nuclear Information System (INIS)

    Kovacs, I.

    1990-01-01

    The iron and silicon are the main impurities in aluminium, they are always present in alloys made from commercially pure base material. The solid solubility of iron in aluminium is very low, therefore its largest amount forms intermetallic compounds the kind of which depends strongly on the other impurities of alloying elements. Although the solid solubility of silicon is much larger than that of the iron, it is the constituent of both the primary and the secondary particles, the structure of which depends in general on the iron-silicon concentration ratio. These Fe and Si containing particles can cause various and basic changes in the macroscopic properties of the alloy. Since commercially pure aluminium has extensive consumer and industrial use, it is very important to know, not only from scientific but also from practical point of view, the effect of iron and silicon on the physical and mechanical properties of aluminium and its alloys. The aim of the ''International Workshop on the Effect of Iron and Silicon in Aluminium and its Alloys'' was to clarify the present knowledge on this subject. The thirty papers presented at the Workshop and collected in this Proceedings cover many important fields of the subject. I hope that they will contribute to both the deeper understanding of the related phenomena and the improvement of technologies for producing better aluminium alloys

  14. Impact properties of aluminium - glass fiber reinforced plastics sandwich panels

    Directory of Open Access Journals (Sweden)

    Mathivanan Periasamy

    2012-06-01

    Full Text Available Aluminium - glass fiber reinforced plastics (GFRP sandwich panels are hybrid laminates consisting of GFRP bonded with thin aluminum sheets on either side. Such sandwich materials are increasingly used in airplane and automobile structures. Laminates with varying aluminium thickness fractions, fiber volume fractions and orientation in the layers of GFRP were fabricated by hand lay up method and evaluated for their impact performance by conducting drop weight tests under low velocity impacts. The impact energy required for initiating a crack in the outer aluminium layer as well as the energy required for perforation was recorded. The impact load-time history was also recorded to understand the failure behavior. The damage depth and the damage area were measured to evaluate the impact resistance. Optical photography and scanning electron micrographs were taken to visualize the crack and the damage zone. The bidirectional cross-ply hybrid laminate (CPHL has been found to exhibit better impact performance and damage resistance than the unidirectional hybrid laminate (UDHL. Increase in aluminium thickness fraction (Al tf and fiber volume fraction (Vf resulted in an increase in the impact energy required for cracking and perforation. On an overall basis, the sandwich panels exhibited better impact performance than the monolithic aluminium.

  15. Irradiation of aluminium alloy materials with electron beam

    International Nuclear Information System (INIS)

    Konno, Osamu; Masumoto, Kazuyoshi

    1982-01-01

    It is a theme with a room for discussion to employ the stainless steel composed of longer half-life materials for the vacuum system of accelerators, from the viewpoint of radiation exposure. Therefore, it is desirable to use aluminium of shorter half-life in place of stainless steel. As a result of investigation on the above theme in the 1.2 GeV electron linac project in Tohoku University, it has been concluded that aluminium alloy vacuum chambers can reduce exposure dose by about one or two figures as compared with stainless steel ones. Of course, aluminium alloy contains trace amounts of Mg, Si, Ti, Cr, Mn, Fe, Zn, Cu and others. Therefore, four kinds of aluminium alloy considered to be usable have been examined for induced radioactivity by electron beam irradiation. Stainless steel SUS 304 has been also irradiated for comparison. Radiation energy has been 30 MeV and 200 MeV. When stainless steel and aluminium alloy were compared, aluminium alloy was very effective for reducing surface dose in low energy irradiation. In 200 MeV irradiation, the dose ratio of aluminium alloy to stainless steel became 1/30 to 1/100 after one week, though the dose difference between these two materials became smaller in 100 days or more after irradiation. If practical inspection and repair are implemented during the period from a few days to one week after shutdown, the aluminium alloy is preferable for exposure dose reduction even in high energy irradiation. (Wakatsuki, Y.)

  16. The determination of trace oxygen in aluminium and aluminium-silicon alloy by helium-3 activation analysis

    International Nuclear Information System (INIS)

    Vandecasteele, C.; Goethals, P.; Kieffer, R.; Hoste, J.

    1975-01-01

    The determination of oxygen in aluminium and aluminium-silicon alloy by helium-3 activation is studied. The 18 F formed from oxygen is separated by distillation followed by precipitation of leadfluorochloride. The chemical yield is determined by activation in an isotopic neutron source. Concentrations of resp. 27 and 64 ng.g -1 with a precision for a single determination of resp. 30 and 13% are found in 99.5% aluminium and in aluminium-silicon (3%) alloy. (author)

  17. Computer modelling of age hardening for cast aluminium alloys

    International Nuclear Information System (INIS)

    Wu, Linda; Ferguson, W George

    2009-01-01

    Age hardening, or precipitation hardening, is one of the most widely adopted techniques for strengthening of aluminium alloys. Although various age hardening models have been developed for aluminium alloys, from the large volume of literature reviewed, it appears that the bulk of the research has been concentrated on wrought aluminium alloys, only a few of the established precipitation models have been applied to the casting aluminium alloys. In the present work, there are two modelling methods that have been developed and applied to the casting aluminium alloys A356 and A357. One is based on the Shercliff-Ashby methodology to produce a process model, by which we mean a mathematical relationship between process variables (alloy composition, ageing temperature and time) and material properties (yield strength or hardness) through microstructure evolution (precipitate radius, volume fraction). The other method is based on the Kampmann and Wagner Numerical (KWN) model which deals with concomitant nucleation, growth and coarsening and is thus capable of predicting the full evolution of the particle size distribution and then a strength model is used to evaluate the resulting change in hardness or yield strength at room temperature by taking into account contributions from lattice resistance, solid solution hardening and precipitation hardening.

  18. Fabrication and Performance Test of Aluminium Alloy-Rice Husk Ash Hybrid Metal Matrix Composite as Industrial and Construction Material

    Directory of Open Access Journals (Sweden)

    Md. Rahat Hossain

    2017-12-01

    Full Text Available Aluminium matrix composites (AMCs used extensively in various engineering fields due to their exceptional mechanical properties. In this present study, aluminium matrix composites (AMCs such as aluminium alloy (A356 reinforced with rice husk ash particles (RHA are made to explore the possibilities of reinforcing aluminium alloy. The stir casting method was applied to produce aluminium alloy (A356 reinforced with various amounts of (2%, 4%, and 6% rice husk ash (RHA particles. Physical treatment was carried out before the rice husk ash manufacturing process. The effect of mechanical strength of the fabricated hybrid composite was investigated. Therefore, impact test, tensile stress, compressive stress, and some other tests were carried out to analyse the mechanical properties. From the experimental results, it was found that maximum tensile, and compressive stress were found at 6% rice husk ash (RHA and aluminium matrix composites (AMCs. In future, the optimum percentages of rice husk ash (RHA to fabricate the hybrid composites will be determined. Also, simulation by finite element method (FEM will be applied for further investigation.

  19. Local electrochemical behaviour of 7xxx aluminium alloys

    NARCIS (Netherlands)

    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

  20. Modelling of micro- and macrosegregation for industrial multicomponent aluminium alloys

    International Nuclear Information System (INIS)

    Ellingsen, K; M'Hamdi, M; Mortensen, D

    2015-01-01

    Realistic predictions of macrosegregation formation during casting of aluminium alloys requires an accurate modeling of solute microsegregation accounting for multicomponent phase diagrams and secondary phase formation. In the present work, the stand alone Alstruc model, a microsegregation model for industrial multicomponent aluminium alloys, is coupled with the continuum model ALSIM which calculates the macroscopic transport of mass, enthalpy, momentum, and solutes as well as stresses and deformation during solidification of aluminium. Alstruc deals with multicomponent alloys accounting for temperature dependent partition coefficients, liquidus slopes and the precipitation of secondary phases. The challenge associated with computation of microsegregation for multicomponent alloys is solved in Alstruc by approximating the phase diagram data by simple, analytical expressions which allows for a CPU-time efficient coupling with the macroscopic transport model. In the present work, the coupled model has been applied in a study of macrosegregation including thermal and solutal convection, solidification shrinkage and surface exudation on an industrial DC-cast billet. (paper)

  1. The role of TiB2 in strengthening TiB2 reinforced aluminium casting composites

    International Nuclear Information System (INIS)

    Chen, Z; Kang, H; Zhao, Y; Zheng, Y; Wang, T

    2016-01-01

    With an aim of developing high quality in situ TiB 2 reinforced aluminium foundry alloy based composites, the conventional direct synthesis method was modified into a two-step route. In step one we optimized the halide salt route to fabricate in situ TiB 2 particulate reinforced aluminium matrix composites and in step two we investigated the effects of the Al-5wt.% TiB 2 composite, as a “master composite”, on strengthening the practical foundry alloys. The in situ formed TiB 2 particles play two roles while strengthening the composites: (1) The grain refinement effect that improves the quality of the alloy matrix; and (2) The interactions between the hard particulates and the matrix add extra increment to the material strength. In different alloy systems, TiB 2 may play distinct roles in these two aspects (figure 1). Further analysis of the strengthening mechanisms shows that particle agglomeration behaviour during solidification is responsible for the latter one. The present work details the role of TiB 2 in strengthening TiB 2 reinforced aluminium casting composites. (paper)

  2. Mechanical Properties of Spray Cast 7XXX Series Aluminium Alloys

    OpenAIRE

    SALAMCI, Elmas

    2014-01-01

    Mechanical properties of spray deposited and extruded 7xxx series aluminium alloys were investigated in peak aged condition. To study the influence of Zn additions on the mechanical behaviour of spray deposited materials, three alloy compositions were selected, namely: SS70 (11.5% Zn), N707 (10.9% Zn) and 7075 (5.6% Zn). After ageing treatment, notched and unnotched specimens of spray deposited alloys were subjected to tensile tests at room temperature. Experimental results showed...

  3. Remediation of phosphate-contaminated water by electrocoagulation with aluminium, aluminium alloy and mild steel anodes.

    Science.gov (United States)

    Vasudevan, Subramanyan; Lakshmi, Jothinathan; Jayaraj, Jeganathan; Sozhan, Ganapathy

    2009-05-30

    The present study provides an electrocoagulation process for the remediation of phosphate-contaminated water using aluminium, aluminium alloy and mild steel as the anodes and stainless steel as the cathode. The various parameters like effect of anode materials, effect of pH, concentration of phosphate, current density, temperature and co-existing ions, and so forth, and the adsorption capacity was evaluated using both Freundlich and Langmuir isotherm models. The adsorption of phosphate preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of adsorbed molecules. The results showed that the maximum removal efficiency of 99% was achieved with aluminium alloy anode at a current density of 0.2 A dm(-2), at a pH of 7.0. The adsorption process follows second-order kinetics.

  4. Mechanical properties of plasma-sprayed layers of aluminium and aluminium alloy on AZ 91

    Czech Academy of Sciences Publication Activity Database

    Kubatík, Tomáš František; Ctibor, Pavel; Mušálek, Radek; Janata, Marek

    2017-01-01

    Roč. 51, č. 2 (2017), s. 323-327 ISSN 1580-2949 R&D Projects: GA ČR(CZ) GP14-31538P Institutional support: RVO:61389021 Keywords : plasma spraying of aluminium * adhesion of coating * wear * magnesium alloy AZ91 Subject RIV: JG - Metallurgy OBOR OECD: Materials engineering Impact factor: 0.436, year: 2016

  5. RESEARCH OF FATIGUE AND MECHANICAL PROPERTIES AlMg1SiCu ALUMINIUM ALLOYS

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    I. Sudhakar

    2015-03-01

    Full Text Available 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 that of steels and has profound applications in the designing of lightweight fortification structures and integrated protection systems. Having limitations such as poor bond integrity, formation of detrimental phases and interfacial reaction between reinforcement and substrate using fusion route to deposit hard particles paves the way to adopt friction stir processing for fabricating surface composites using different sizes of boron carbide particles as reinforcement on armour grade 7075 aluminium alloy as matrix in the present investigation. Wear and ballistic tests were carried out to assess the performance of friction stir processed AA7075 alloy. Significant improvement in wear resistance of friction stir processed surface composites is attributed to the change in wear mechanism from abrasion to adhesion. It has also been observed that the surface metal matrix composites have shown better ballistic resistance compared to the substrate AA7075 alloy. Addition of solid lubricant MoS2 has reduced the depth of penetration of the projectile to half that of base metal AA7075 alloy. For the first time, the friction stir processing technique was successfully used to improve the wear and ballistic resistances of armour grade high strength AA7075 alloy.

  7. Investigating aluminum alloy reinforced by graphene nanoflakes

    Energy Technology Data Exchange (ETDEWEB)

    Yan, S.J., E-mail: shaojiuyan@126.com [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Dai, S.L.; Zhang, X.Y.; Yang, C.; Hong, Q.H.; Chen, J.Z. [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Lin, Z.M. [Aviation Industry Corporation of China, Beijing 100022 (China)

    2014-08-26

    As one of the most important engineering materials, aluminum alloys have been widely applied in many fields. However, the requirement of enhancing their mechanical properties without sacrificing the ductility is always a challenge in the development of aluminum alloys. Thanks to the excellent physical and mechanical properties, graphene nanoflakes (GNFs) have been applied as promising reinforcing elements in various engineering materials, including polymers and ceramics. However, the investigation of GNFs as reinforcement phase in metals or alloys, especially in aluminum alloys, is still very limited. In this study, the aluminum alloy reinforced by GNFs was successfully prepared via powder metallurgy approach. The GNFs were mixed with aluminum alloy powders through ball milling and followed by hot isostatic pressing. The green body was then hot extruded to obtain the final GNFs reinforced aluminum alloy nanocomposite. The scanning electron microscopy and transmission electron microscope analysis show that GNFs were well dispersed in the aluminum alloy matrix and no chemical reactions were observed at the interfaces between the GNFs and aluminum alloy matrix. The mechanical properties' testing results show that with increasing filling content of GNFs, both tensile and yield strengths were remarkably increased without losing the ductility performance. These results not only provided a pathway to achieve the goal of preparing high strength aluminum alloys with excellent ductilitybut they also shed light on the development of other metal alloys reinforced by GNFs.

  8. Development of Niobium Boron grain retainer for aluminium silicon alloys

    OpenAIRE

    Nowak, Magdalena

    2011-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University Aluminium castings with a large grain structure have poor mechanical properties which are primarily due to casting defects as opposed to fine grain structure. The grain refinement practice using chemical addition is well established for wrought alloys, however in the case of casting alloys, the practice of adding grain refiners and the impact on castability is not well established. The additio...

  9. Contribution to comprehensive study of aluminium alloy Aa 5083 ...

    African Journals Online (AJOL)

    PROMOTING ACCESS TO AFRICAN RESEARCH ... Corrosion induced by elemental mercury in aqueous media of industrial Aluminium alloys AA5083 used in heat exchanger industries of natural gas liquefaction has been studied by linear sweep voltammétry on ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  10. Structure analysis of 3104 aluminium alloy applied to deep drawing

    Energy Technology Data Exchange (ETDEWEB)

    Klyszewski, A.; Lech-Grega, M.; Zelechowski, J.; Szymanski, W. [Light Metals Div., Skawina (Poland). Inst. of Non-Ferrous Metals

    2000-07-01

    Optical and electron microscopy observations and X-ray investigations of 3104 aluminium alloy ingots and bands after experimental heat treatment were carried out. The influence of ingots homogenisation temperature and parameters of material heat treatment after hot rolling on structure, texture and earing of band 0.3 mm thick was analysed. (orig.)

  11. Galvanic corrosion study of aluminium alloy plates mounted to stainless and mild steel bolts by accelerated exposure test

    OpenAIRE

    MREMA, Emmanuel; ITOH, Yoshito; KANEKO, Akira; HIROHATA, Mikihito

    2016-01-01

    Despite the fact that aluminium alloy members have a proven durability over stainless steel members, their joint fasteners like bolts, nuts and washers are drawn from steel material due to aluminium alloy inferior mechanical properties. Bare contact between aluminium alloy members and stainless steel fasteners results to galvanic corrosion of aluminium alloy members. A corrosion behaviour study was carried out on different aluminium alloy types with different surface treatments mounted to sta...

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

    Directory of Open Access Journals (Sweden)

    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.

  13. The effects of radiation on aluminium alloys in the core of energy nuclear reactors

    International Nuclear Information System (INIS)

    Petrossian, V.G.

    1995-01-01

    One of the attractive directions in the worldwide practice of nuclear installations is the replacement of expensive zirconium alloy with more cheap materials, particularly aluminium allo. For Heat Supply Nuclear Plants (HSNP) with approximately 473 K core temperatures, the use of heat-resistant aluminium alloys seems to be reasonable. The present work is concerned with the studies on radiation effects on aluminium alloy, and interaction between the alloy and coolant in the reactor core. (author). 2 refs., 3 figs., 1 tab

  14. EXPERIMENTAL INVESTIGATION ON TRIBOLOGICAL CHARACTERISTICS OF SILICON NITRIDE REINFORCED ALUMINIUM METAL MATRIX COMPOSITES

    Directory of Open Access Journals (Sweden)

    D. BHUVANESH

    2017-05-01

    Full Text Available Aluminium alloy (LM25 reinforced with silicon nitride was fabricated by liquid metallurgy route. The fabricated composite was investigated for dry sliding wear behaviour by conducting experiments using pin-on-disc tribometer. Set of experiments were planned using Taguchi’s technique and data analysis was carried out using L27 orthogonal array. Analysis of Variance (ANOVA technique was used to determine the significance of parameter with respect to wear rate. Signal-to-Noise ratio was employed to detect the most and least influential parameter as well as their level of influence. ‘Smaller the wear’ characteristic was chosen for the analysis of dry sliding wear. Results implied that, the load has the primary effect on the wear succeeded by the effect of sliding velocity and sliding distance. Scanning Electronic Microscopic studies were carried out on worn surfaces to understand the wear mechanism.Tribological results indicated that LM25 aluminium alloy could be better utilized as a material for piston, rotor and bearings for long life in low speed applications.

  15. Phase formation in multicomponent monotectic aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mirkovic, Djordje; Groebner, Joachim; Schmid-Fetzer, Rainer [Institute of Metallurgy, Clausthal University of Technology (Germany)

    2008-07-01

    Alloys with a miscibility gap in the liquid state are potential materials for advanced bearings in automotive and other applications. While binary alloys, such as Al-Pb or Al-Bi, are well known, the information available for ternary monotectic Al-alloys is scarce. However, the phase formation in multicomponent alloys is not only more challenging from a scientific aspect, it is also a prerequisite for a focused development of advanced alloys. This motivated our detailed study of monotectic Al-Bi-Cu-Sn alloys including both experimental and computational thermodynamic methods. Based on the initially established systematic classification of monotectic ternary Al-alloys, the first promising monotectic reaction was observed in the ternary Al-Bi-Zn system. Further ternary systems Al-Cu-Sn, Al-Bi-Sn, Al-Bi-Cu and Bi-Cu-Sn were investigated as basis for quaternary Al-Bi-Cu-Sn alloys. Experimental investigations of phase equilibria, enthalpies and solidification microstructures were combined with thermodynamic modeling. The results demonstrate that the developed precise thermodynamic description is vital to reveal the distinct multicomponent monotectic features of pertinent phase diagrams. The solidification paths of ternary monotectic alloy systems, Al-Bi-Zn, Al-Sn-Cu and Al-Bi-Cu, were also studied using thermodynamic calculations, revealing specific details of phase formation during solidification of selected alloys.

  16. Microstructural and mechanical properties analysis of an aluminium matrix composite reinforced with the amorphous alloy Al{sub 87.5}Ni{sub 4}Sm{sub 8.5} consolidated by hot extrusion; Propriedades mecanicas e microestruturais de um composito com matrix de aluminio e reforco amorfo de Al{sub 87.5}Ni{sub 4}Sm{sub 8.5} consolidado por extrusao a quente por extrusao a quente

    Energy Technology Data Exchange (ETDEWEB)

    Aliaga, L.C.R.; Bolfarini, C.; Kiminami, C.S.; Botta, W.J. [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais; Peres, M.M., E-mail: peresmm@yahoo.com.b [Universidade Federal de Itajuba (UNIFEI), Itabira, MG (Brazil)

    2010-07-01

    The aim of this work is the microstructure and the mechanical properties analysis of an aluminium matrix composite reinforced with the Al{sub 87.5}Ni{sub 4}Sm{sub 8.5} amorphous alloy. The amorphous alloy was produced by melt-spinning and fragmented in powder particles by milling. Pure aluminium power was moistured with amorphous powder in a proportion of 80:20 (% weight) and processed by milling using 350 rpm during 30 minutes for the generation of a homogeneous composite powder. This product was consolidated by extrusion at 235 deg C, ram speed of 2mm/min and extrusion ratio of 7/1, generating a compact and cylindrical bar with 3 mm of width. The result sample was characterized by Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC) and by X-Ray Diffraction (XRD). Microhardness and compression tests show an improvement on the mechanical properties. (author)

  17. Aluminium Matrix Composites Reinforced with Co-continuous Interlaced Phases Aluminium-alumina Needles

    Directory of Open Access Journals (Sweden)

    Elvio de Napole Gregolin

    2002-09-01

    Full Text Available An Al-5SiO2 (5 wt% of SiO2 aluminium matrix fiber composite was produced where the reinforcement consists of fossil silica fibers needles. After being heat-treated at 600 °C, the original fiber morphology was retained but its microstructure changed from solid silica to an interconnected (Al-Si/Al2O3 interlaced structure named co-continuous composite. A technique of powder metallurgy, using commercial aluminium powder and the silica fibers as starting materials, followed by hot extrusion, was used to produce the composite. The co-continuous microstructure was obtained partially or totally on the fibers as a result of the reaction, which occurs during the heat treatment, first by solid diffusion and finally by the liquid Al-Si in local equilibrium, formed with the silicon released by reaction. The internal structure of the fibers was characterized using field emission electron microscope (FEG-SEM and optical microscopy on polished and fractured samples.

  18. Recycling of aluminium scrap for secondary Al-Si alloys.

    Science.gov (United States)

    Velasco, Eulogio; Nino, Jose

    2011-07-01

    An increasing amount of recycled aluminium is going into the production of aluminium alloy used for automotive applications. In these applications, it is necessary to control and remove alloy impurities and inclusions. Cleaning and fluxing processes are widely used during processing of the alloys for removal of inclusions, hydrogen and excess of magnesium. These processes use salt fluxes based in the system NaCl-KCl, injection of chlorine or mixture of chlorine with an inert gas. The new systems include a graphite wand and a circulation device to force convection in the melt and permit the bubbling and dispersion of reactive and cleaning agents. This paper discusses the recycling of aluminium alloys in rotary and reverberatory industrial furnaces. It focuses on the removal of magnesium during the melting process. In rotary furnaces, the magnesium lost is mainly due to the oxidation process at high temperatures. The magnesium removal is carried out by the reaction between chlorine and magnesium, with its efficiency associated to kinetic factors such as concentration of magnesium, mixing, and temperature. These factors are also related to emissions generated during the demagging process. Improvements in the metallic yield can be reached in rotary furnaces if the process starts with a proper salt, with limits of addition, and avoiding long holding times. To improve throughput in reverberatories, start the charging with high magnesium content material and inject chlorine gas if the molten metal is at the right temperature. Removal of magnesium through modern technologies can be efficiently performed to prevent environmental problems.

  19. Impact toughness of laser surface alloyed Aluminium

    CSIR Research Space (South Africa)

    Mabhali, Luyolo AB

    2012-03-01

    Full Text Available with intermetallic phases and metal matrix composites were achieved during laser alloying. Brittle fracture of the SiC particles and transgranular cracking of the intermetallic phases was observed for the laser alloyed samples, while ductile fracture was observed...

  20. Grain refinement of zinc-aluminium alloys

    International Nuclear Information System (INIS)

    Zaid, A.I.O.

    2006-01-01

    It is now well-established that the structure of the zinc-aluminum die casting alloys can be modified by the binary Al-Ti or the ternary Al-Ti-B master alloys. in this paper, grain refinement of zinc-aluminum alloys by rare earth materials is reviewed and discussed. The importance of grain refining of these alloys and parameters affecting it are presented and discussed. These include parameters related to the Zn-Al alloys cast, parameters related to the grain refining elements or alloys and parameters related to the process. The effect of addition of other alloying elements e.g. Zr either alone or in the presence of the main grain refiners Ti or Ti + B on the grain refining efficiency is also reviewed and discussed. Furthermore, based on the grain refinement and the parameters affecting it, a criterion for selection of the optimum grain refiner is suggested. Finally, the recent research work on the effect of grain refiners on the mechanical behaviour, impact strength, wear resistance, and fatigue life of these alloys are presented and discussed. (author)

  1. Site specific SEM/FIB/TEM for analysis of lubricated sliding wear of aluminium alloy composites

    International Nuclear Information System (INIS)

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

    2006-01-01

    Although extensive research has been undertaken into the dry sliding wear of aluminium alloys, only limited work has been reported on lubricated wear. In this paper, the lubricated sliding wear of some powder derived aluminium alloy composites is reported. Stereo pairs of the worn surface were obtained in the SEM and digitally reconstructed to give an accurate projection of the surface topography. Analysis of the average surface roughness (R a ) along chosen sections provided quantitative information about the wear mechanism. Following this, dual beam focused ion beam (FIB) was undertaken to further explore the features revealed by the SEM surface reconstructions, with TEM sections removed from selected regions. Surface deformation was confined to a narrow layer, typically 1μm thick. Subgrain size within the subsurface layer was comparable to that found in dry sliding wear tests. Reinforcement fracture occurred in the surface particles only. The resultant fragments were often incorporated back into the surface following detachment, such that the total volume fraction reinforcement at the surface was greater than in the bulk. Thus, the dynamic surface topography was a result of three factors: surface deformation, local detachment of reinforcement and re-incorporation of the fragments back into the surface

  2. Corrosion behaviour of 2124 aluminium alloy-silicon carbide metal matrix composites in sodium chloride environment

    International Nuclear Information System (INIS)

    Singh, Nirbhay; Vadera, K.K.; Ramesh Kumar, A.V.; Singh, R.S.; Monga, S.S.; Mathur, G.N.

    1999-01-01

    Aluminium alloy based particle reinforced metal matrix composites (MMCs) are being considered for a range of applications. Their mechanical properties have been investigated in detail, but more information about their corrosion resistance is needed. In this investigation, the corrosion behaviour of silicon carbide particulates (SiC p )-2124 aluminium metal matrix composites was studied in 3 wt% sodium chloride solution by means of electrochemical technique and optical microscope. The effects of weight percentages and particle size of silicon carbide particulates on corrosion behaviour of the composite were studied in NaCl and it was observed that corrosion rate increases linearly with the increasing weight percentage of SiC p . The corrosion rate of the MMC increases by increasing the size of SiC particles. Anodization improved corrosion resistance of the composites. (author)

  3. Results of the Experiment: Welding of Aluminium Alloy in Microgravity

    Science.gov (United States)

    Ferretti, S.; Amadori, K.; Boccalatte, A.; Alessandrini, M.; Freddi, A.; Persiani, F.; Poli, G.

    2002-01-01

    An experiment on "dendritic growth in aluminium alloy welding" was performed by the UNIBO team during the 3rd Student Parabolic Flight Campaign and the 30th Professional Parabolic Flight Campaign organised by ESA. Its purpose was to achieve a better understanding of crystal growth during tungsten inert gas (TIG) welding of an aluminium alloy to define the main parameters affecting the process under microgravity condition. The experiment had 4 phases : The paper discusses different aspects of the research, paying particularly attention not only to the influence of gravity, but also to other factors influencing welding microstructure, such as the Marangoni effect and the thermal transfer from the electrode to the material. The paper conclude the dissertation of the results offering new perspectives for welding studies and proposing a new approach to the scientific community to investigate this materials processes for manufacturing.

  4. Emission properties of aluminium-lithium alloy

    International Nuclear Information System (INIS)

    Bondarenko, G.G.; Shishkov, A.V.

    1995-01-01

    High secondary emission properties at comparatively low operation temperatures were obtained when investigating aluminum-lithium alloy Al - 2.2 mass % Li. The maximal value of the coefficient of secondary electron emission for alloy, activated under optimal conditions, is achieved at comparatively low energy of primary electrons, equal to 600 eV. Low value of the first critical potential (15 ± 2 eV) was obtained. It is important for operation of secondary emission cathodes. 12 refs.; 4 figs

  5. LASER CLADDING ON ALUMINIUM BASE ALLOYS

    OpenAIRE

    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...

  6. Laser surface alloying of aluminium-transition metal alloys

    International Nuclear Information System (INIS)

    Almeida, A.; Vilar, R.

    1998-01-01

    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 high-strength 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-Mo and Al-Nb surface alloys by alloying Cr, Mo or Nb powder into an Al and 7175 Al alloy substrate using a CO 2 laser . This paper presents a review of the work that has been developed at Instituto Superior Tecnico on laser alloying of Al-TM alloy, over the last years. (Author) 16 refs

  7. Prediction of deformation textures in asymmetric rolling of aluminium alloys

    OpenAIRE

    Shore, Diarmuid; Nguyen-Minh, Tuan; Kestens, Leo; Van Bael, Albert

    2015-01-01

    Asymmetric cold rolling (ASR) has been shown to have potential to improve the formability of aluminium sheet alloys in deep drawing by increasing the normal plastic anisotropy, mainly as a result of the additional shear strains it imposes and the consequent alteration of the crystallographic texture. It is generally found that the process produces shear strains that vary across the sheet thickness, resulting in heterogeneity of the texture and related properties. While it may be a typical des...

  8. Research progress of aluminium alloy endplates for PEMFCs

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Yu.; Hou, Junbo [Fuel Cell system and Engineering Laboratory, Dalian Institute of Chemical and Physics, Chinese Academy of Sciences, Dalian 116023 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Hou, Ming; Yan, Xiqiang; Luo, Xiaokuan; Shao, Zhigang; Yi, Baolian [Fuel Cell system and Engineering Laboratory, Dalian Institute of Chemical and Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2007-04-15

    The endplate is a crucial component in a proton exchange membrane fuel cell (PEMFC) stack. It can provide the necessary rigidity and strength for the stack. An aluminium alloy is one of the ideal materials for PEMFC endplates because of its low density and high rigidity. But it does not meet the requirements of corrosion resistance and electrical insulation in PEMFC environments. In this work, methods of sealing treatments and the conditions of aluminium alloy anodization were investigated. Corrosion resistances of the samples prepared by different technologies were evaluated in simulated PEMFC environments. The results showed that the corrosion resistance of the samples sealed by epoxy resin was greatly improved compared with those sealed in boiling water, and the samples anodized at a constant current density performed better than those anodized at a constant voltage. By insulation measurements, all of the samples showed good electrical insulation. The aluminium alloy endplate anodized at a constant current density and sealed with thermosetting bisphenol-A epoxy resin exhibited promising potential for practical applications by assembling it in a PEMFC stack and applying a life test. (author)

  9. Machinability of magnesium and aluminium alloys. Part I: cutting resistance

    International Nuclear Information System (INIS)

    Balout, B.; Songmene, V.; Masounave, J.

    2002-01-01

    Aluminium (2.7 g/cm 3 ) and magnesium (1.7 g/cm 3 ) are two competing light metals with similar mechanical properties and excellent possibilities for recycling. The forming of magnesium is often seen as an impediment to its use. New forming techniques using magnesium shavings are being developed, particularly in Japan. The machining of magnesium alloys by removal of metal raises safety concerns (risk of fire), which limits many potential applications of magnesium. The purpose of this work is to clarify and compare the machining properties of these two types of metal and better understand the mechanisms that may explain the differences in behaviour. Such a comparison could eventually provide an estimate of the cost of producing shavings for the manufacture of aluminium and magnesium parts through forging and extrusion, which would limit environmental pollution. Based on an analysis of cutting resistance during machining, it was demonstrated that magnesium alloys are easier to machine than similar aluminium alloys. Magnesium shavings are shorter than those of 6061-T6, but are especially more regular than those of A356, and their size is independent of cutting speed. It was also demonstrated that the fragility of materials can be characterized based on the results of cutting resistance produced during drilling

  10. Aluminium base amorphous and crystalline alloys with Fe impurity

    International Nuclear Information System (INIS)

    Sitek, J.; Degmova, J.

    2006-01-01

    Aluminium base alloys show remarkable mechanical properties, however their low thermal stability still limits the technological applications. Further improvement of mechanical properties can be reached by partial crystallization of amorphous alloys, which gives rise to nanostructured composites. Our work was focused on aluminium based alloys with Fe, Nb and V additions. Samples of nominal composition Al 90 Fe 7 Nb 3 and Al 94 Fe 2 V 4 were studied in amorphous state and after annealing up to 873 K. From Moessbauer spectra taken on the samples in amorphous state the value of f-factor was determined as well as corresponding Debye temperatures were calculated. Annealing at higher temperatures induced nano and microcrystalline crystallization. Moessbauer spectra of samples annealed up to 573 K are fitted only by distribution of quadrupole doublets corresponding to the amorphous state. An increase of annealing temperature leads to the structural transformation, which consists in growth of nanometer sized aluminium nuclei. This is partly reflected in Moessbauer parameters. After annealing at 673 K intermetallic phase Al 3 Fe and other Al-Fe phases are created. In this case Moessbauer spectra are fitted by quadrupole doublets. During annealing up to 873 K large grains of Fe-Al phases are created. (authors)

  11. Preparation of Ti-aluminide reinforced in situ aluminium matrix composites by reactive hot pressing

    International Nuclear Information System (INIS)

    Roy, D.; Ghosh, S.; Basumallick, A.; Basu, B.

    2007-01-01

    Aluminium based metal matrix composites reinforced with in situ Ti-aluminide and alumina particles were prepared by reactive hot pressing a powder mix of aluminium and nanosized TiO 2 powders. The reinforcements were formed in situ by exothermal reaction between the TiO 2 nano crystalline powder and aluminium. The thermal characteristics of the in situ reaction were studied with the aid of Differential scanning calorimetry (DSC). X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and Scanning electron microscopy (SEM) techniques were employed to study the microstructural architecture of the composites as a function of hot pressing temperature and volume percent reinforcement. Microhardness measurements on the as prepared in situ aluminium matrix composites exhibit significant increase in hardness with increase in hot pressing temperature and volume fraction of reinforcement

  12. Development of textile-reinforced carbon fibre aluminium composites manufactured with gas pressure infiltration methods

    OpenAIRE

    W. Hufenbach; M. Gude; A. Czulak; J. Śleziona; A. Dolata-Grosz; M. Dyzia

    2009-01-01

    Purpose: The aim of his paper is to show potential of textile-reinforced carbon fibre aluminium composite with advantage of the lightweight construction of structural components subjected to thermo-mechanical stress.Design/methodology/approach: The manufacture of specimens of the carbon fibre-reinforced aluminium was realised with the aid of an advanced differential gas pressure infiltration technique, which was developed at ILK, TU Dresden.Findings: The gas pressure infiltration technology e...

  13. Aluminium alloys containing iron and nickel; Alliages d'aluminium contenant du fer et du nickel

    Energy Technology Data Exchange (ETDEWEB)

    Coriou, H.; Fournier, R.; Grall, L.; Hure, J. [Commissariat a l' Energie atomique, Centre d' Etudes Nucleaires de Saclay, Departement de Metallurgie et de Chimie Appliquee (France); Herenguel, J.; Lelong, P. [Centre de Recherches d' Antony, des Trefileries et Laminoirs du Havre (France)

    1958-07-01

    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)

  14. Evolution of morphology in solidifying aluminium alloys

    NARCIS (Netherlands)

    Dijkstra, W.O.

    2007-01-01

    In the thesis two different models of solidification of aluminum alloys are presented and analyzed. The first 1--D solidification model is derived from the conservation of solute, heat and mass. With numerical experiments it is shown that simulations with the Finite Difference discretization must

  15. The effect of palm kernel shell ash on the mechanical properties of as-cast aluminium alloy matrix composites

    Directory of Open Access Journals (Sweden)

    Isiaka Oluwole OLADELE

    2016-06-01

    Full Text Available The present work describes the effect of palm kernel shell ash (PKSA as reinforcement on the mechanical properties of As-cast aluminium alloy. Recycled aluminium alloy from cylinder of an automotive engine block was degreased by using premium motor spirit (PMS also known as petrol, washed thoroughly with soap and water and sun dried for 5 days. The palm kernel shell was screened of dirt and other unwanted foreign materials before being roasted in furnace. The ash was further pulverized by laboratory ball mill machine followed by sieving to obtain particle sizes of 106 µm and divided into two parts. One portion was treated with NaOH solution while the other part was left as untreated before they are used to reinforced molten aluminium alloy in predetermined proportions. The newly developed composites were characterized with respect to their mechanical properties in response to the tests that were carried out on them. The results indicate that palm kernel shell ash can be used as potential reinforcing material for automobile applications.

  16. Friction stir spot welding of dissimilar aluminium alloys

    International Nuclear Information System (INIS)

    Bozkurt, Yahya

    2016-01-01

    Friction stir spot welding (FSSW) has been proposed as an effective technology to spot weld the so-called “difficult to be welded” metal alloys such as thin sheets aluminum alloys and dissimilar materials. FSSW is derived from friction stir welding technology, its principle benefit being low cost joining, lower welding temperature and shorter welding time than conventional welding methods. In this study, dissimilar AlMg 3 and AlCu 4 Mg 1 aluminium alloy plates were FSSWed by offsetting the low strength sheet on upper side of the weld. The effects of tool rotation speed on the microstructure, lap shear fracture load (LSFL), microhardness and fracture features of the weld are investigated by constant welding parameters. The maximum LSFL was obtained by increasing the tool rotational speed. However, the joints exhibited pull-out nugget fracture mode under lap shear tensile testing conditions. The largest completely bonded zone was observed as 5.86 mm which was narrower at the opposite position of the joint. Key words: friction stir spot welding, aluminium alloys, mechanical properties, dissimilar joint, welding parameters

  17. Experimental Studies on SiC and Rice Husk Ash Reinforced Al Alloy Composite

    Directory of Open Access Journals (Sweden)

    Shivaprakash Y. M.

    2018-01-01

    Full Text Available In this research work Aluminium alloy with Cu (4.5% as the major alloying element is used as the matrix in which SiC and Rice Husk Ash (RHA are dispersed to develop a hybrid composite. The dispersion is done by the motorized stir casting arrangement. The composite is fabricated by varying the proportions of the reinforcements in the base alloy. The composite specimens were tested for density changes, hardness and the wear. The microstructure images showed a uniform dispersion of the reinforcements in the matrix and this resulted in higher strength to weight ratio. The increase in strength of the composite is probably attributed to the increase in the dislocation density. Also, the abrasive wear resistance of the produced composite is found to be superior as compared to the matrix alloy because of the hard-ceramic particles in the reinforcements.

  18. Design of Grain Refiners for Aluminium Alloys

    Science.gov (United States)

    Tronche, A.; Greer, A. L.

    The efficiency of a grain refiner can be quantified as the number of grains per nucleant particle in the solidified product. Even for effective refiners in aluminium, such as Al-5Ti-1B, it is known from experiments that efficiencies are very low, at best 10-3 to 102. It is of interest to explore the reasons for such low values, and to assess the prospects for increased efficiency though design of refiners. Recently it has been shown [1] that a simple recalescence-based model can make quantitative predictions of grain size as a function of refiner addition level, cooling rate and solute content. In the model, the initiation of grains is limited by the free growth from nucleant particles, the size distribution of which is very important. The present work uses this model as the basis for discussing the effect of particle size distribution on grain refiner performance. Larger particles (of TiB2 in the case of present interest) promote greater efficiency, as do narrower size distributions. It is shown that even if the size distribution could be exactly specified, compromises would have to be made to balance efficiency (defined as above) with other desirable characteristics of a refiner.

  19. Influence of nanoporous structure on mechanical strength of aluminium and aluminium alloy adhesive structural joints

    International Nuclear Information System (INIS)

    Spadaro, C; Dispenza, C; Sunseri, C

    2006-01-01

    The influence of surface treatments on the mechanical strength of adhesive joints was investigated. The attention was focused on AA2024 alloy because it is extensively used in both the automotive and aerospace industries. Adhesive joints fabricated with pure aluminium were also investigated in order to evidence possible differences in the surface features after identical treatments. Before joining with a commercial epoxy adhesive, metal substrates were subjected to different kinds of treatment and the surfaces were characterized by SEM analysis. The formation of a microporous surface in the AA2024 alloy, upon etching and anodizing, is discussed on the basis of the role of the intermetallic particles and their electrochemical behaviour with respect to the aluminium matrix. Moreover, nanostructured porous oxide layers on both type of substrate were also formed, as a consequence of the anodizing process. Differences in their morphologies were revealed as a function of both the applied voltage and the presence of alloying elements. On this basis, an explanation of the different values of fracture energy measured by means of T-peel tests carried out on the corresponding joints was attempted

  20. Corrosion-electrochemical and mechanical properties of aluminium-berylium alloys alloyed by rare-earth metals

    International Nuclear Information System (INIS)

    Safarov, A.M.; Odinaev, Kh.E.; Shukroev, M.Sh.; Saidov, R.Kh.

    1997-01-01

    In order to study influence of rare earth metals on corrosion-electrochemical and mechanical properties of aluminium-berylium alloys the alloys contain 1 mass % beryllium and different amount of rare earth metals were obtained.-electrochemical and mechanical properties of aluminium-berylium alloys. The electrochemical characteristics of obtained alloys, including stationary potential, potentials of passivation beginning and full passivation, potentials of pitting formation and re passivation were defined.

  1. Nanostructural hierarchy increases the strength of aluminium alloys.

    Science.gov (United States)

    Liddicoat, Peter V; Liao, Xiao-Zhou; Zhao, Yonghao; Zhu, Yuntian; Murashkin, Maxim Y; Lavernia, Enrique J; Valiev, Ruslan Z; Ringer, Simon P

    2010-09-07

    Increasing the strength of metallic alloys while maintaining formability is an interesting challenge for enabling new generations of lightweight structures and technologies. In this paper, we engineer aluminium alloys to contain a hierarchy of nanostructures and possess mechanical properties that expand known performance boundaries-an aerospace-grade 7075 alloy exhibits a yield strength and uniform elongation approaching 1 GPa and 5%, respectively. The nanostructural architecture was observed using novel high-resolution microscopy techniques and comprises a solid solution, free of precipitation, featuring (i) a high density of dislocations, (ii) subnanometre intragranular solute clusters, (iii) two geometries of nanometre-scale intergranular solute structures and (iv) grain sizes tens of nanometres in diameter. Our results demonstrate that this novel architecture offers a design pathway towards a new generation of super-strong materials with new regimes of property-performance space.

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

    Science.gov (United States)

    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.

  3. 3D printing of high-strength aluminium alloys.

    Science.gov (United States)

    Martin, John H; Yahata, Brennan D; Hundley, Jacob M; Mayer, Justin A; Schaedler, Tobias A; Pollock, Tresa M

    2017-09-20

    Metal-based additive manufacturing, or three-dimensional (3D) printing, is a potentially disruptive technology across multiple industries, including the aerospace, biomedical and automotive industries. Building up metal components layer by layer increases design freedom and manufacturing flexibility, thereby enabling complex geometries, increased product customization and shorter time to market, while eliminating traditional economy-of-scale constraints. However, currently only a few alloys, the most relevant being AlSi10Mg, TiAl6V4, CoCr and Inconel 718, can be reliably printed; the vast majority of the more than 5,500 alloys in use today cannot be additively manufactured because the melting and solidification dynamics during the printing process lead to intolerable microstructures with large columnar grains and periodic cracks. Here we demonstrate that these issues can be resolved by introducing nanoparticles of nucleants that control solidification during additive manufacturing. We selected the nucleants on the basis of crystallographic information and assembled them onto 7075 and 6061 series aluminium alloy powders. After functionalization with the nucleants, we found that these high-strength aluminium alloys, which were previously incompatible with additive manufacturing, could be processed successfully using selective laser melting. Crack-free, equiaxed (that is, with grains roughly equal in length, width and height), fine-grained microstructures were achieved, resulting in material strengths comparable to that of wrought material. Our approach to metal-based additive manufacturing is applicable to a wide range of alloys and can be implemented using a range of additive machines. It thus provides a foundation for broad industrial applicability, including where electron-beam melting or directed-energy-deposition techniques are used instead of selective laser melting, and will enable additive manufacturing of other alloy systems, such as non-weldable nickel

  4. 3D printing of high-strength aluminium alloys

    Science.gov (United States)

    Martin, John H.; Yahata, Brennan D.; Hundley, Jacob M.; Mayer, Justin A.; Schaedler, Tobias A.; Pollock, Tresa M.

    2017-09-01

    Metal-based additive manufacturing, or three-dimensional (3D) printing, is a potentially disruptive technology across multiple industries, including the aerospace, biomedical and automotive industries. Building up metal components layer by layer increases design freedom and manufacturing flexibility, thereby enabling complex geometries, increased product customization and shorter time to market, while eliminating traditional economy-of-scale constraints. However, currently only a few alloys, the most relevant being AlSi10Mg, TiAl6V4, CoCr and Inconel 718, can be reliably printed; the vast majority of the more than 5,500 alloys in use today cannot be additively manufactured because the melting and solidification dynamics during the printing process lead to intolerable microstructures with large columnar grains and periodic cracks. Here we demonstrate that these issues can be resolved by introducing nanoparticles of nucleants that control solidification during additive manufacturing. We selected the nucleants on the basis of crystallographic information and assembled them onto 7075 and 6061 series aluminium alloy powders. After functionalization with the nucleants, we found that these high-strength aluminium alloys, which were previously incompatible with additive manufacturing, could be processed successfully using selective laser melting. Crack-free, equiaxed (that is, with grains roughly equal in length, width and height), fine-grained microstructures were achieved, resulting in material strengths comparable to that of wrought material. Our approach to metal-based additive manufacturing is applicable to a wide range of alloys and can be implemented using a range of additive machines. It thus provides a foundation for broad industrial applicability, including where electron-beam melting or directed-energy-deposition techniques are used instead of selective laser melting, and will enable additive manufacturing of other alloy systems, such as non-weldable nickel

  5. Metallurgical aspects of corrosion resistance of aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Reboul, M.C. [Pechiney Voreppe Research Centre France (France); CNRS-INP Grenoble, SIMAP-INP Grenoble, Universite France, Saint Martin d' Heres Cedex (France); Baroux, B. [SIMAP-INP, Grenoble University, 1130 rue de la piscine, Saint Martin d' Heres Cedex (France)

    2011-03-15

    Aluminium is the second most often used metal after steel. In this paper, the most current uses of aluminium alloys are first summarised. Then, their different corrosion modes, i.e. pitting, crevice, filiform, galvanic and structural corrosion (including inter-granular, exfoliation and stress corrosion cracking) are reviewed, with particular attention paid to metallurgical factors controlling the corrosion process. For each mode, some instances of possible in-service failure are given, followed by the discussion of the involved mechanisms and the presentation of appropriate solutions to prevent corrosion. Last, passivity and polarisation behaviour are discussed with reference to stainless steels. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Mechanical Properties of SiC, Al2O3 Reinforced Aluminium 6061-T6 Hybrid Matrix Composite

    Science.gov (United States)

    Murugan, S. Senthil; Jegan, V.; Velmurugan, M.

    2018-04-01

    This paper contains the investigation of tensile, compression and impact characterization of SiC, Al2O3 reinforced Aluminium 6061-T6 matrix hybrid composite. Hybrid matrix composite fabrication was done by stir casting method. An attempt has been made by keeping Al2O3 percentage (7%) constant and increasing SiC percentage (10, 15, and 20%). After fabricating, the samples were prepared and tested to find out the various mechanical properties like tensile, compressive, and impact strength of the developed composites of different weight % of silicon carbide and Alumina in Aluminium alloy. The main objective of the study is to compare the values obtained and choose the best composition of the hybrid matrix composite from the mechanical properties point of view.

  7. Improving the wettability of 2024 aluminium alloy by means of cold plasma treatment

    Science.gov (United States)

    Polini, W.; Sorrentino, L.

    2003-05-01

    Aluminium alloys are heavily used to manufacture structural parts in the aeronautic industry because of its lightness and its corrosion resistance. These alloys are successfully used in other industrial fields too, such as railway, automotive and naval industries. The need to contrast the severe use conditions and the heavy stresses developing in aeronautic field implies to protect the surfaces of the structures in aluminium alloy by any deterioration. To preserve by deterioration, it is necessary to make aluminium more suitable to be coated by protective paint. In the aeronautic industry, a complex and critical process is used in order to enhance both wettability and adhesive properties of aluminium alloy surfaces. Cold plasma treatment represents an efficient, clean and economic alternative to activate aluminium surfaces. The present work deals with air cold plasma treatment of 2024 aluminium alloy surfaces. The influence of dc electrical discharge cold plasma parameters on wettability of 2024 aluminium alloy surfaces has been studied. A set of process variables (voltage, time and air flow rate) has been identified and used to conduct some experimental tests on the basis of design of experiment (DOE) techniques. The experimental results show that the proposed plasma process may considerably increase aluminium alloy wettability. These results represent the first step in trying to optimise the aluminium adhesion by means of this non-conventional manufacturing process.

  8. Electrochemical characteristics of a carbon fibre composite and the associated galvanic effects with aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z., E-mail: zuojia.liu@gmail.com; Curioni, M.; Jamshidi, P.; Walker, A.; Prengnell, P.; Thompson, G.E.; Skeldon, P.

    2014-09-30

    Highlights: • Exposed carbon fibres on two defined regions (“front” and “side”) are a focus of the investigation in NaCl electrolyte. • The exposed carbon fibres on the side and front regions are responsible for a high cathodic current density. • The NaCl + CuSO{sub 4} electrolyte was used to investigate the cathodic polarization behaviour of the exposed carbon fibres. • Galvanic coupling behaviour between the composite and aluminium alloys (AA7075-T6 and AA1050) was measured in NaCl electrolyte. • The higher galvanic current density measured on AA1050 alloy introduced a higher dissolution rate than the AA7075-T6 alloy. - Abstract: The electrochemical behaviour of a carbon fibre reinforced epoxy matrix composite in 3.5% NaCl and 3.5% NaCl + 0.5 M CuSO{sub 4} electrolytes was examined by potentiodynamic polarisation, potentiostatic polarisation and scanning electron microscopy. Exposed carbon fibres on two defined regions (“front” and “side”) are a focus of the investigation. The large size of the exposed carbon fibres on the side region is responsible for a higher cathodic current density than the front region in the NaCl electrolyte. The deposition of copper on the front surface of composite confirmed that the significantly higher cathodic current resulted from the exposure of the fibres to the NaCl electrolyte. Galvanic coupling between the composite and individual aluminium alloys (AA7075-T6 and AA1050) was used to measure galvanic potentials and galvanic current densities. The highly alloyed AA7075-T6 alloy and its high population density of cathodic sites compared to the AA1050 acted to reduce the galvanic effect when coupled to the composite front or side regions.

  9. Recovery of Actinides from Actinide-Aluminium Alloys: Chlorination Route

    International Nuclear Information System (INIS)

    Mendes, E.; Malmbeck, R.; Soucek, P.; Jardin, R.; Glatz, J.P.; Cassayre, L.

    2008-01-01

    A method for recovery of actinides (An) from An-Al alloys formed by electrochemical separation of metallic spent nuclear fuel on solid aluminium electrodes in molten chloride salts is described. The proposed route consists of three main steps: -) vacuum distillation of salt adhered on the electrodes, -) chlorination of An-Al alloy by pure chlorine gas and -) sublimation of formed AlCl 3 . A thermochemical study of the route was performed to determine important chemical reactions and to find optimum experimental conditions for all process steps. Vacuum distillation of the electrode is efficient for complete removal of remaining salt and most fission products, full chlorination of the An-Al alloys is possible at any working temperature and evaporation of AlCl 3 is achieved by heating under argon. Experiments have been carried out using U-Al alloy in order to define parameters providing full alloy chlorination without formation of volatile UCl 5 and UCl 6 . It was shown that full chlorination of An-Al alloys without An losses should be possible at a temperature approx. 150 deg. C. (authors)

  10. Recovery of Actinides from Actinide-Aluminium Alloys: Chlorination Route

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, E.; Malmbeck, R.; Soucek, P.; Jardin, R.; Glatz, J.P. [European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany); Cassayre, L. [Laboratoire de Genie Chimique (LGC), Universite Paul Sabatier, UMR CNRS 5503, 118 route de Narbonne, 31062 Toulouse Cedex 04 (France)

    2008-07-01

    A method for recovery of actinides (An) from An-Al alloys formed by electrochemical separation of metallic spent nuclear fuel on solid aluminium electrodes in molten chloride salts is described. The proposed route consists of three main steps: -) vacuum distillation of salt adhered on the electrodes, -) chlorination of An-Al alloy by pure chlorine gas and -) sublimation of formed AlCl{sub 3}. A thermochemical study of the route was performed to determine important chemical reactions and to find optimum experimental conditions for all process steps. Vacuum distillation of the electrode is efficient for complete removal of remaining salt and most fission products, full chlorination of the An-Al alloys is possible at any working temperature and evaporation of AlCl{sub 3} is achieved by heating under argon. Experiments have been carried out using U-Al alloy in order to define parameters providing full alloy chlorination without formation of volatile UCl{sub 5} and UCl{sub 6}. It was shown that full chlorination of An-Al alloys without An losses should be possible at a temperature approx. 150 deg. C. (authors)

  11. Anodization of cast aluminium alloys produced by different casting methods

    Directory of Open Access Journals (Sweden)

    K. Labisz

    2008-08-01

    Full Text Available In this paper the usability of two casting methods, of sand and high pressure cast for the anodization of AlSi12 and AlSi9Cu3 aluminium cast alloys was investigated. With defined anodization parameters like electrolyte composition and temperature, current type and value a anodic alumina surface layer was produced. The quality, size and properties of the anodic layer was investigated after the anodization of the chosen aluminium cast alloys. The Alumina layer was observed used light microscope, also the mechanical properties were measured as well the abrasive wear test was made with using ABR-8251 equipment. The researches included analyze of the influence of chemical composition, geometry and roughness of anodic layer obtained on aluminum casts. Conducted investigations shows the areas of later researches, especially in the direction of the possible, next optimization anodization process of aluminum casting alloys, for example in the range of raising resistance on corrosion to achieve a suitable anodic surface layer on elements for increasing applications in the aggressive environment for example as materials on working building constructions, elements in electronics and construction parts in air and automotive industry.

  12. Microstructures of alloyed and dispersed hard particles in the aluminium surface

    CSIR Research Space (South Africa)

    Pityana, S

    2010-03-01

    Full Text Available Laser surface alloying of A1200 aluminium alloy was carried out using a 4.4 kW Nd:YAG laser. Powder mixtures of SiC and TiC hard particles were injected into the laser generated melt pool on the aluminium substrate using a commercial powder feeder...

  13. Grain Refinement of Commercial EC Grade 1070 Aluminium Alloy for Electrical Application

    OpenAIRE

    Hassanabadi, Massoud

    2015-01-01

    The aluminium alloys for electrical conductivity applications are generally not grain refinedsince the addition of grain refiners drops the electrical conductivity by introducing impuritiesinto the melt. Non-grain refined aluminium may lead to bar fracture and cracks during themetalworking process. The present study focuses to find an optimum balance between the grain refiner addition andthe electrical conductivity of commercial EC grade 1070 aluminium alloy for electricalapplication. In orde...

  14. Two-Scale Modelling of Effects of Microstructure and Thermomechanical Properties on Dynamic Performance of an Aluminium Alloy

    Science.gov (United States)

    2010-09-01

    Influences of microstructure and properties of an aluminium alloy on resistance to dynamic perforation are predicted using a decoupled multiscale ... simulated performance. Library parameters typical for aluminium alloys (Kohn, 1969) are used for the macroscopic equation of state of Al 2139, details of...Two-Scale Modelling of Effects of Microstructure and Thermomechanical Properties on Dynamic Performance of an Aluminium Alloy by J. D

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

    DEFF Research Database (Denmark)

    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...... initiate doxide growth at the intermetallic particles while growth and corrosion performance of oxide was found tobe a function of anions type and their concentration. Further, steam treatment with phosphates exhibited better performance under acetic acid salt spray and filiform corrosion test whereas...

  16. Deviatoric Response of AN Armour-Grade Aluminium Alloy

    Science.gov (United States)

    Appleby-Thomas, G. J.; Hazell, P. J.; Millett, J.; Bourne, N. K.

    2009-12-01

    Aluminium alloys such as 5083 H32 are established light-weight armour materials. As such, the shock response of these materials is of great importance. The shear strength of a material under shock loading provides an insight into its ballistic performance. In this investigation embedded manganin stress gauges have been employed to measure both the longitudinal and lateral components of stress during plate-impact experiments over a range of impact stresses. In turn, these results were used to determine the shear strength and to investigate the time dependence of lateral stress behind the shock front to give an indication of material response.

  17. Fracture strength of aluminium alloys under rapid loading conditions

    International Nuclear Information System (INIS)

    Joshi, K.D.; Rav, Amit S.; Sur, Amit; Kaushik, T.C.; Gupta, Satish C.

    2016-04-01

    Spall fracture strength and dynamic yield strength of aluminium alloys have been measured at high strain rates generated in plate impact experiments carried out at different impact velocities ranging from 174 m/s to 560 m/s using single stage gas gun facility. In each experiment, the free surface velocity history of the sample plate of aluminium alloy has been derived from time resolved Doppler shift measured employing indigenously developed velocity interferometer system for any reflector (VISAR). The free surface velocity history so determined has been used to evaluate the spall fracture strength and dynamic yield strength of the target material. The two kinds of alloys of aluminium namely Al2014-T4 and Al2024-T4 have been investigated in these experiments. In Al2014-T4 target plates, the spall strength determined from free surface velocity history recorded for impact velocities of 179 m/s, 307 m/s, 398 m/s and 495m/s is 0.90 GPa, 0.96 GPa, 1.0 GPa and 1.1 GPa, respectively. The average strain rates just ahead of spall pulse have been found to vary from ∼ 1.1×10 4 /s to 2.4×10 4 /s. The dynamic yield strength derived from the measured Hugoniot elastic limit ranges from 0.36 GPa to 0.40 GPa. The spall strength for Al2024-T4 samples has been determined to be 1.11 GPa, 1.18 GPa and 1.42 GPa, at impact velocities of 174 m/s, 377 m/s and 560 m/s, respectively. The corresponding average strain rates range from 1.9×104/s to 2.5×104/s. The dynamic yield strength of Al2024-T4 at these impact velocities has been found to vary from 0.37 GPa to 0.43 GPa. The measured spall strengths in all these experiments are higher than the quasi-static value of 0.511 GPa for Al2014-T4 and 0.470 GPa for Al2024. Similarly, the dynamic yield strengths are also larger than the quasi-static value of 0.355 GPa for Al2014-T4 and 0.360 GPa for Al2024-T4. These experimental studies suggest that at high strain rates, both the alloys of aluminium offer higher resistance against the tensile

  18. Friction stir welding of 6061 aluminium alloy

    International Nuclear Information System (INIS)

    Abdel Rahman, M.A.M.S.

    2009-01-01

    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

  19. B2-ordered iron-aluminium alloys strengthening. Influence of additions (Ni and B) and microstructure

    International Nuclear Information System (INIS)

    Colas, David

    2004-01-01

    We study the effects of additions (Ni and B) and microstructure on the mechanical behaviour of 40 at. % Al iron-aluminium alloys. From a macroscopic point of view, we show that nickel reinforces FeAl alloys over the whole temperature range, but that it simultaneously leads to emphasize the room temperature brittleness of these alloys through a cleavage stress decrease. We confirm powder metallurgy grain refining interest to enhance yield stress as well as fracture resistance. We show that nickel-induced yield stress effect is additive to 'Hall-Petch' one. Also, we point out that the strengthening phenomena (nickel or grain size) cause the yield stress anomaly, which these alloys usually present, to be hidden. Through a dislocation structures analysis of deformed materials we precise that low temperature nickel-induced solid solution hardening (SSH) cannot be explained on the basis of classical SSH theories but more probably through nickel influence upon the Peierls stress. Moreover, we show that the APB tubes dragging model may be compatible with our microscopic and macroscopic results about the anomaly. Eventually, we put into relation a dynamic super-dislocations multiplication process observation (in situ transmission microscopy) with the nickel-containing alloys tendency to cleavage. (author) [fr

  20. Quasicrystal-reinforced Mg alloys.

    Science.gov (United States)

    Kyun Kim, Young; Tae Kim, Won; Hyang Kim, Do

    2014-04-01

    The formation of the icosahedral phase (I-phase) as a secondary solidification phase in Mg-Zn-Y and Mg-Zn-Al base systems provides useful advantages in designing high performance wrought magnesium alloys. The strengthening in two-phase composites (I-phase + α -Mg) can be explained by dispersion hardening due to the presence of I-phase particles and by the strong bonding property at the I-phase/matrix interface. The presence of an additional secondary solidification phase can further enhance formability and mechanical properties. In Mg-Zn-Y alloys, the co-presence of I and Ca 2 Mg 6 Zn 3 phases by addition of Ca can significantly enhance formability, while in Mg-Zn-Al alloys, the co-presence of the I-phase and Mg 2 Sn phase leads to the enhancement of mechanical properties. Dynamic and static recrystallization are significantly accelerated by addition of Ca in Mg-Zn-Y alloy, resulting in much smaller grain size and more random texture. The high strength of Mg-Zn-Al-Sn alloys is attributed to the presence of finely distributed Mg 2 Sn and I-phase particles embedded in the α -Mg matrix.

  1. Laser surface alloying of aluminium-transition metal alloys

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

    Pokhmurskii, V.I.; Zin, I.M.; Vynar, V.A.; Bily, L.M.

    2011-01-01

    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.

  3. Characterization and structure of precipitates in 6xxx Aluminium Alloys

    International Nuclear Information System (INIS)

    Holmestad, Randi; Bjørge, Ruben; Ehlers, Flemming J H; Torsæter, Malin; Marioara, Calin D; Andersen, Sigmund J

    2012-01-01

    Solute atom nanoscale precipitates are responsible for the favourable mechanical properties of heat treatable aluminium alloys such as Al-Mg-Si (6xxx). The shape, structure and strengthening properties of age-hardening precipitates depend on alloy composition and thermo-mechanical history. We seek an improved understanding of the physics related to nucleation and precipitation on the atomistic level in these alloys. Once these mechanisms are sufficiently well described and understood, the hope is that 'alloy design' simulations can assist tailoring of materials with desired properties. In pure Al-Mg-Si we have determined the structure of nearly all the known metastable precipitate phases, by combining advanced TEM techniques (such as high resolution TEM and nano-beam diffraction) with atom probe tomography and density functional theory. We are now studying effects of additions /substitutions of Cu, Ag and/or Ge that promote formation of more disordered precipitates, employing aberration corrected high angle annular dark field scanning TEM. We find that all metastable precipitates contain variations of a widely spaced 'Si/Ge network'. In spite of disorder or defects, this network is surprisingly well ordered, with hexagonal projected sub-cell dimensions a = b ≅ 0.4 nm and c (along the fully coherent precipitate main growth direction) equal to 0.405 nm or a multiple of it.

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

    International Nuclear Information System (INIS)

    Lazarev, Eh.M.; Sapozhnikova, L.V.; Shabanova, M.E.; Pod'yachev, V.N.; Kornilova, Z.I.

    1987-01-01

    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

  5. Microstructure and mechanical properties of thixoformed A319 aluminium alloy

    International Nuclear Information System (INIS)

    Salleh, M.S.; Omar, M.Z.; Syarif, J.; Alhawari, K.S.; Mohammed, M.N.

    2014-01-01

    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

  6. Laser deposition of (Cu + Mo) alloying reinforcements on AA1200 substrate for corrosion improvement

    CSIR Research Space (South Africa)

    Popoola, API

    2011-10-01

    Full Text Available Poor corrosion performance of aluminium alloys in marine environment has been a subject of intensive research recently. Aluminium substrate was alloyed with a combination of two metallic powders (Cu + Mo) using an Nd: YAG solid state laser...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Electron microscope investigation into dislocation structure of cast aluminium alloys

    International Nuclear Information System (INIS)

    Zolotorevskij, V.S.; Orelkina, T.A.; Istomin-Kastrovskij, V.V.

    1978-01-01

    By applying the diffraction electron microscopy method, the general specific features of the disclocation structure of cast binary alloys of aluminium with different additions were established. It is shown that in most alloys, when they undergo cooling in the process of crystallization at the rate of about 850 deg/min, the cellular dislocation structure is formed. It is shown that in all the alloys studied, the total density of dislocations of one order is about-10 9 cm -2 , which exceeds by 1 to 2 orders of magnitude the value which follows from the Tiller theory of concentration stresses. It has been experimentally established that the contribution of shrinkage and thermal stresses to the formation of a dislocation structure is rather insignificant; yet the dislocation density values calculated according to the size of dendritic cells and the medium angles of their disorientation are close to those determined by the electron-microscopic method. This is the basis for making a supposition that the greater part of the dislocations in castings are formed as a result of comparing dendritic branches with one another, which are disoriented in respect to each other

  9. Quantitative prediction of solute strengthening in aluminium alloys.

    Science.gov (United States)

    Leyson, Gerard Paul M; Curtin, William A; Hector, Louis G; Woodward, Christopher F

    2010-09-01

    Despite significant advances in computational materials science, a quantitative, parameter-free prediction of the mechanical properties of alloys has been difficult to achieve from first principles. Here, we present a new analytic theory that, with input from first-principles calculations, is able to predict the strengthening of aluminium by substitutional solute atoms. Solute-dislocation interaction energies in and around the dislocation core are first calculated using density functional theory and a flexible-boundary-condition method. An analytic model for the strength, or stress to move a dislocation, owing to the random field of solutes, is then presented. The theory, which has no adjustable parameters and is extendable to other metallic alloys, predicts both the energy barriers to dislocation motion and the zero-temperature flow stress, allowing for predictions of finite-temperature flow stresses. Quantitative comparisons with experimental flow stresses at temperature T=78 K are made for Al-X alloys (X=Mg, Si, Cu, Cr) and good agreement is obtained.

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

    DEFF Research Database (Denmark)

    Aggerbeck, Martin; Canulescu, Stela; Dirscherl, Kai

    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 substrat...

  11. Laser surface alloying (LSA) of aluminium (AA 1200) with TiB2 for hardness improvement

    CSIR Research Space (South Africa)

    Popoola, AP

    2010-10-01

    Full Text Available The present work deals with the development of Aluminium metal matrix composite (MMC) using TiB2 reinforcement. The aim is to improve the microhardness property of the substrate. The surface of the aluminium was sand blasted to improve its laser...

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

    NARCIS (Netherlands)

    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

  13. In-situ electron microscopy studies on the tensile deformation mechanisms in aluminium 5083 alloy

    CSIR Research Space (South Africa)

    Motsi, G

    2014-10-01

    Full Text Available In this study tensile deformation mechanisms of aluminium alloy 5083 were investigated under observations made from SEM equipped with a tensile stage. Observations during tensile testing revealed a sequence of surface deformation events...

  14. The determination of sulphur in copper, nickel and aluminium alloys by proton activation analysis

    International Nuclear Information System (INIS)

    Vandecasteele, C.; Dewaele, J.; Esprit, M.; Goethals, P.

    1981-01-01

    The 34 S(p,n) 34 sup(m)Cl reaction, induced by 13 MeV protons is used for the determination of sulphur in copper, nickel and aluminium alloys. The 34 sup(m)Cl is separated by repeated precipitation as silver chloride. The results obtained were resp. 3.08 +- 0.47, 1.47 +- 0.17 and -1 for copper, nickel and aluminium alloys. (orig.)

  15. Incorporation of transition metal ions and oxygen generation during anodizing of aluminium alloys

    International Nuclear Information System (INIS)

    Habazaki, H.; Konno, H.; Shimizu, K.; Nagata, S.; Skeldon, P.; Thompson, G.E.

    2004-01-01

    Enrichment of nickel at the alloy/film interface and incorporation of nickel species into the anodic film have been examined for a sputtering-deposited Al-1.2at.%Ni alloy in order to assist understanding of oxygen generation in barrier anodic alumina films. Anodizing of the alloy proceeds in two stages similarly to other dilute aluminium alloys, for example Al-Cr and Al-Cu alloys, where the Gibbs free energies per equivalent for formation of alloying element oxide exceeds the value for alumina. In the first stage, a nickel-free alumina film is formed, with nickel enriching in an alloy layer, 2 nm thick, immediately beneath the anodic oxide film. In the second stage, nickel atoms are oxidized together with aluminium, with oxygen generation forming gas bubbles within the anodic oxide film. This stage commences after accumulation of about 5.4 x 10 15 nickel atoms cm -2 in the enriched alloy layer. Oxygen generation also occurs when a thin layer of the alloy, containing about 2.0 x 10 19 nickel atoms m -2 , on electropolished aluminium, is completely anodized, contrasting with thin Al-Cr and Al-Cu alloy layers on electropolished aluminium, for which oxygen generation is essentially absent. A mechanism of oxygen generation, based on electron impurity levels of amorphous alumina and local oxide compositions, is discussed in order to explain the observations

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

    International Nuclear Information System (INIS)

    Zaifol Samsu; Muhammad Daud; Siti Radiah Mohd Kamarudin; Nur Ubaidah Saidin; Azali Muhammad; Mohd Shaari Ripin; Rusni Rejab; Mohd Shariff Sattar

    2010-01-01

    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)

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

    DEFF Research Database (Denmark)

    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......: • 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....

  18. Vacuum brazing of aluminium metal matrix composite (55 vol.% SiC{sub p}/A356) using aluminium-based filler alloy

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Jitai, E-mail: niujitai@163.com [Harbin Institute of Technology (China); Zhengzhou University (China); Luo, Xiangwei; Tian, Hao [Zhengzhou University (China); Brnic, Josip [University of Rijka (Croatia)

    2012-11-20

    Highlights: Black-Right-Pointing-Pointer The proper filler metal has been developed, especially for contents of Mg and Si. Black-Right-Pointing-Pointer The pressure device has been designed for specimen in vacuum brazing process. Black-Right-Pointing-Pointer The accurate measurement method for shear strength of lap joint has been found. Black-Right-Pointing-Pointer The brazing temperature of 560 Degree-Sign C has been optimised. Black-Right-Pointing-Pointer The micro-mechanism has been discussed for SiC{sub p}/Al composites' brazing joint. - Abstract: Aluminium matrix composites with high volume fractions of SiC particles, as the reinforcements, are potentially suitable materials for electronic packaging. These composites, due to their poor weldability, however, have very limited applications. The microstructure and shear strengths of the bonds made in 55 vol.% SiC{sub p}/A356 composite, using an aluminium based filler alloy containing Cu, Si, Mg and Ni, were investigated in this paper. The brazing temperature had a clear effect on the bond integrity, and the samples brazed at 560 Degree-Sign C demonstrated good bonding between the filler alloy and the SiC particles. The maximum shear strength achieved in this work was 102 MPa.

  19. Study of Surface Roughness and Cutting force in machining for 6068 Aluminium alloy

    Science.gov (United States)

    Purushothaman, D.; Kaushik Yanamundra, Krishna; Krishnan, Gokul; Perisamy, C.

    2018-04-01

    Metal matrix composites, in particular, Aluminium Hybrid Composites are gaining increasing attention for applications in air and land because of their superior strength to weight ratio, density and high temperature resistance. Aluminium alloys are being used for a wide range of applications in Aerospace and Automobile industries, to name a few. The Aluminium Alloy 6068 has been used as the specimen. It is mainly composed of Aluminium (93.22 - 97.6 %), Magnesium (0.60 - 1.2 %), Silicon (0.60 - 1.4 %) and Bismuth (0.60 - 1.1 %). Aluminium 6068 is widely used for manufacturing aircraft structures, fuselages and wings. It is also extensively used in fabricating automobile parts such as wheel spacers. In this study, tests for the measurement of surface roughness and cutting force has been carried out on the specimen, the results evaluated and conclusions are drawn. Also the simulation of the same is carried out in a commercial FE software – ABAQUS.

  20. The effect of surface treatment and gaseous rust protection paper on the atmospheric corrosion stability of aluminium alloy

    International Nuclear Information System (INIS)

    Gao Guizhong

    1992-03-01

    The experimental results of atmospheric corrosion of 166 aluminium alloy of Al-Mg-Si-Cu system and 167 aluminium alloy of Al-Mg-Si-Cu-Fe-Ni system for different surface treatment and different wrapping papers used are introduced. The results show: 1. The composition of aluminium alloy has some effect on the performance of atmospheric corrosion stability and the local corrosion depth for 167 aluminium alloy specimen is considerable. 2. After 8 years storage, the 167 aluminium alloy tubular specimen, which was treated with surface treatment in deionized water at 100 ∼ 230 C degree, has no spot of atmospheric corrosion found. 3. Within the test period, the performance of atmospheric corrosion stability by sulphuric-acid anodization film is remarkable. 4. The No. 19 gaseous rust protection paper has no effect of atmospheric corrosion stability on the 166 and 167 aluminium alloys which were treated with quenching and natural ageing method

  1. A Fundamental Approach to Developing Aluminium based Bulk Amorphous Alloys based on Stable Liquid Metal Structures and Electronic Equilibrium - 154041

    Science.gov (United States)

    2017-03-28

    AFRL-AFOSR-JP-TR-2017-0027 A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal Structures and...to 16 Dec 2016 4.  TITLE AND SUBTITLE A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal...Air Force Research Laboratory for accurately predicting compositions of new amorphous alloys specifically based on aluminium with properties superior

  2. Processing and characterization of aluminium alloys or composites exhibiting low-temperature or high-rate superplasticity

    International Nuclear Information System (INIS)

    Huang, J. C.

    1997-01-01

    Wide applications of superplastic forming still face several problems, one is the high temperature that promotes grain growth, another is the low forming rate that makes economically inefficient. The current study is intended to develop a series of fabrication and thermomechanical processing, so as to result in materials possessing either low temperature superplasticity (LTSP) or high rate superplasticity (HRSP). The former has been achieved in the cast Al alloys, while the latter was accomplished in powder-metallurgy aluminium matrix composites. The aluminium alloys, after special thermomechanical processes, exhibited LTSP from 300 to 450 degree C with elongations varying from 300 to 700 %. The LTSP sheets after 700 % elongation at 350 degree C still possessed fine grains 3.7 μm size and narrow surface solute depletion zones 11 μm in with, resulting in a post-SP T6 strength of 500 MPa, significantly higher than that of the HTSP superplasticity alloys tested at 525 degree C or above. Meanwhile, it was found that LTSP materials may be transferred into HTSP materials simply by adding a preloading at 300-400 degree C for a small amount of work. As for the endeavor in making HRSP materials, 2024Al/SiC, 6061Al/SiC and Al/Al 3 Ti systems processed by powder metallurgy or mechanical alloying methods are under investigation. The average sizes of the reinforcing SiC or A13Ti particles, as well as the grain size are all around 1 μm. The aluminium composites have exhibited HRSP at 525-620 degree C and 10 -2 -10 -1 s -l , with elongations varying from 150 to 350 %. This ultimate goal is to produce an alloy or composite exhibiting low temperature and high strain rate superplasticity (LT and HRSP). (author)

  3. Wear and microstructural characteristics of spray atomized zircon sand reinforced LM13 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, K.; Pandey, O.P. [School of Physics and Materials Science, Thapar University Patiala, Punjab (India)

    2010-07-15

    The requirement of the high performance light weight materials demands the development of varieties of materials within the economical range to get it commercialized. Light weight aluminium alloys are used in several structural applications like automotive, aerospace, defense industry and other fields of engineering. The ceramic particle reinforced aluminium metal matrix composites (AMCs) have emerged as a suitable candidate for commercial applications. A variety of processing routes have been adopted to manufacture AMCs. In the present work LM13 alloy reinforced with zircon sand is formed via spray forming. During experimentation a self prepared convergent-divergent nozzle is used for inert gas atomization of the melt which is subsequently deposited on copper substrate placed vertically below the atomizer. The zircon sand particles are injected in the atomization zone by external injectors aligned perpendicular to the gas atomization axis. Zircon sand has been found to have new promising economical commercial candidate due to its easy availability and good mechanical properties like high hardness, high modulus of elasticity and good thermal stability. The microhardness of cast alloy and spray formed composite shows that the spray formed zircon sand reinforced composite has higher hardness. Also the lower wear rate has been observed in case of the zircon sand reinforced AMC as compared to LM13 alloy. This behaviour is further analyzed in light of microstructural features of the spray deposited composite using optical and scanning electron microscope (SEM). A comparative study of this material (LM13/Zircon sand) with the parent alloy (LM13) is presented in this work. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  4. Mechanical and Tribological Characteristics of TIG Hardfaced Dispersive Layer by Reinforced with Particles Extruded Aluminium

    Directory of Open Access Journals (Sweden)

    R. Dimitrova

    2017-05-01

    Full Text Available The article presents the results of the implemented technology for generation of hardfaced dispersive layers obtained by additive material containing reinforcing phase of non-metal particles. The wear resistant coatings are deposited on pure aluminium metal matrix by shielded gas metal-arc welding applying tungsten inert gas (TIG with extruded aluminium wire reinforced by particles as additive material. Wire filler is produced by extrusion of a pack containing metalized and plated by flux micro/nano SiC particles. The metalized particles implanting in the metal matrix and its dispersive hardfacing are realized by solid-state welding under conditions of hot plastic deformation. Tribological characteristics are studied of the hardfaced layers of dispersive reinforced material on pure aluminium metal matrix with and without flux. Hardness profiles of the hardfaced layers are determined by nanoindentation. The surface layers are studied by means of Scanning Electron Microscopy (SEM and Energy Dispersive X-ray (EDX analysis. Increase by 15-31 % of the wear resistance of the hardfaced layers and 30-40 % of their hardness was found, which is due to the implanted in the layer reinforcing phase of metalized micro/nano SiC particles.

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

    International Nuclear Information System (INIS)

    Nakamura, Yasushi; Kobayashi, Yoshio; Kakurai, Yousuke

    1993-01-01

    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)

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

    International Nuclear Information System (INIS)

    Mouturat, P.

    1966-06-01

    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) [fr

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

    International Nuclear Information System (INIS)

    Fuoco, Ricardo; Correa, Edison Roberto; Correa, Alzira V.O.; Bocalini Junior, Mario

    1992-01-01

    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)

  8. Physicochemical properties of aluminium alloys with elements of II and III groups of periodic table

    International Nuclear Information System (INIS)

    Eshov, B.B.

    2016-01-01

    The purpose of the present work is to establish the mechanism and regularities of changes of physicochemical properties of binary and multicomponent aluminium alloys with elements of II and III groups of periodic table as well as optimization and elaboration of new alloys.

  9. Galvanic corrosion of laser weldments of AA6061 aluminium alloy

    International Nuclear Information System (INIS)

    Rahman, A.B.M. Mujibur; Kumar, S.; Gerson, A.R.

    2007-01-01

    Galvanic corrosion of laser welded AA6061 aluminium alloy, arising from the varying rest potentials of the various weldment regions, was examined. The weld fusion zone is found to be the most cathodic region of the weldment while the base material is the most anodic region. The rate of galvanic corrosion, controlled by the cathodic process at the weld fusion zone, increases with time until a steady state maximum is reached. On galvanic corrosion the corrosion potential of the weld fusion zone shifts in the positive direction and the free corrosion current increases. It is proposed that the cathodic process at the weld fusion zone causes a local increase in pH that in turn causes dissolution of the surface film resulting in the loss of Al to solution and the increase of intermetallic phases. The increase in galvanic corrosion may result from either the build up of the intermetallic phases in the surface layer and/or significant increase in surface area of the weld fusion zone due to the porous nature of the surface layer

  10. Modelling of Local Necking and Fracture in Aluminium Alloys

    International Nuclear Information System (INIS)

    Achani, D.; Eriksson, M.; Hopperstad, O. S.; Lademo, O.-G.

    2007-01-01

    Non-linear Finite Element simulations are extensively used in forming and crashworthiness studies of automotive components and structures in which fracture need to be controlled. For thin-walled ductile materials, the fracture-related phenomena that must be properly represented are thinning instability, ductile fracture and through-thickness shear instability. Proper representation of the fracture process relies on the accuracy of constitutive and fracture models and their parameters that need to be calibrated through well defined experiments. The present study focuses on local necking and fracture which is of high industrial importance, and uses a phenomenological criterion for modelling fracture in aluminium alloys. As an accurate description of plastic anisotropy is important, advanced phenomenological constitutive equations based on the yield criterion YLD2000/YLD2003 are used. Uniaxial tensile tests and disc compression tests are performed for identification of the constitutive model parameters. Ductile fracture is described by the Cockcroft-Latham fracture criterion and an in-plane shear tests is performed to identify the fracture parameter. The reason is that in a well designed in-plane shear test no thinning instability should occur and it thus gives more direct information about the phenomenon of ductile fracture. Numerical simulations have been performed using a user-defined material model implemented in the general-purpose non-linear FE code LS-DYNA. The applicability of the model is demonstrated by correlating the predicted and experimental response in the in-plane shear tests and additional plane strain tension tests

  11. Mushy Zone Properties and Castability of Aluminium Foundry Alloys

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Nanostructure of aluminium alloy 2024: Segregation, clustering and precipitation processes

    International Nuclear Information System (INIS)

    Sha, G.; Marceau, R.K.W.; Gao, X.; Muddle, B.C.; Ringer, S.P.

    2011-01-01

    Variations in solute element distribution occurring in a commercial 2024 aluminium alloy during isothermal ageing treatments at 170 deg. C for up to 120 h have been characterized using atom probe tomography. An early (0.5 h at 170 deg. C) rapid increase in hardness was correlated with the formation of fine scale (average 24 atom) solute clusters, comprising principally Mg and Cu, but with minor concentrations of Si and Zn. There was, in addition, evidence of significant segregation of Mg, Cu and Si to at least some fraction of grain boundaries and existing matrix dislocations. At peak hardness (80 h at 170 deg. C) the microstructure comprised coarse precipitates of S phase, with a composition approaching stoichiometric Al 2 CuMg, a dense distribution of Guinier-Preston-Bagaryatsky zones elongated parallel to in a matrix of α-Al and a residual distribution of smaller equiaxed solute clusters. Both the clusters and zones contained predominantly Mg and Cu, with minor concentrations of Si and Zn. The S phase contained small but significant (0.5-1.8 at.%) concentrations of Si, which was non-uniformly distributed in elongated domains within the laths of the S phase. In overaged samples (114 h at 170 deg. C) the microstructure comprised almost exclusively coarse S phase, Al 2 Mg(Cu,Si), in assemblies suggestive of a combination of precipitate coarsening and coalescence.

  13. Wear Response of Aluminium 6061 Composite Reinforced with Red Mud at Elevated Temperature

    Directory of Open Access Journals (Sweden)

    R. Dabral

    2017-09-01

    Full Text Available The present work is focused on the investigations on dry sliding wear behaviour of aluminium metal matrix composite at room and elevated temperature. Aluminium metal matrix composites reinforced with red mud are prepared by stir casting method. The experiments are planned using Taguchi technique. An orthogonal array, analysis of variance and signal to noise ratio are used to check the influence of wear parameters like temperature, percentage of reinforcement, mesh size, load, sliding distance and sliding speed on dry sliding wear of composites. The optimal testing parameters are found and their values are calculated which are then compared with predicted values. A reasonable agreement is found between predicted and actual values. The model prepared in the present work can be effectively used to predict the specific wear rate of the composites.

  14. Influence of tool pin in friction stir welding on activated carbon reinforced aluminium metal matrix composite

    Science.gov (United States)

    DijuSamuel, G.; Raja Dhas, J. Edwin

    2017-10-01

    This paper focus on impact of tool pin in friction stir welding on activated carbon reinforced aluminium metal matrix composite. For fabrication of metal matrix composite AA6061 is used as matrix and activated carbon is used as reinforcement and it is casted using modified stir casting technique. After casting metal matrix composite has undergone various microstructure tests like SEM,EDAX and XRD. FSW is carried out in this metal matrix composite by choosing various tool pin profile like square,round,Threaded round, hexagon and taper. The quality of welded plates is measured in terms of ultimate tensile strength and hardness.

  15. ECAP – New consolidation method for production of aluminium matrix composites with ceramic reinforcement

    Directory of Open Access Journals (Sweden)

    Mateja Šnajdar Musa

    2013-06-01

    Full Text Available Aluminium based metal matrix composites are rapidly developing group of materials due to their unique combination of properties that include low weight, elevated strength, improved wear and corrosion resistance and relatively good ductility. This combination of properties is a result of mixing two groups of materials with rather different properties with aluminium as ductile matrix and different oxides and carbides added as reinforcement. Al2O3, SiC and ZrO2 are the most popular choices of reinforcement material. One of the most common methods for producing this type of metal matrix composites is powder metallurgy since it has many variations and also is relatively low-cost method. Many different techniques of compacting aluminium and ceramic powders have been previously investigated. Among those techniques equal channel angular pressing (ECAP stands out due to its beneficial influence on the main problem that arises during powder compaction and that is a non-uniform distribution of reinforcement particles. This paper gives an overview on ECAP method principles, advantages and produced powder composite properties.

  16. Investigation of aluminium-rich alloy system of aluminium-strontium-silicium

    International Nuclear Information System (INIS)

    Ganiev, I.N.; Vakhobov, A.B.; Dzhuraev, T.D.; Alidzhanov, F.N.

    1976-01-01

    An area of the solid solution based on aluminium was studied, and the surface was plotted of the liquidus adjoining the apex of the aluminium corner of the strontium-aluminium-silicon system. The investigation was carried out by microstructure and differential thermal analyses and by the measurement of the microhardness of the component phases. A combined solubility of silicon and strontium in aluminium was studied along three radial sections at Sr-to-Si ratios of 1/2, 1/1 and 2/1. The relationships of ''composition vs. Microhardness'', obtained in these sections, made it possible to define the boundaries of the phase regions in the aluminium corner of the strontium-aluminium-silicon system at 500 deg C. The greatest solubility is that along the Al-SrAl 2 Si 2 section at a Sr/Si ratio of 1/2. A further increase in the content of strontium brings about a drop in the solubility of silicon in solid aluminium. The projection of the liquidus surface of the strontium-aluminium-silicon system, rich in aluminium, includes four surfaces of primary crystallization: α-Al, SrAl 4 , SrAl 2 Si 2 and Si. The system comprises a section of Al-SrAl 2 Si 2 representing a quasibinary system of an eutectic type. The eutectic reaction takes place at a temperature of 640 deg C. The quasibinary Al-SrAl 2 Si 2 section divides the aluminium corner of the Sr-Al-Si system into two independent systems Al-SrAl 4 -SrAl 2 Si 2 and Al-Si-SrAl 2 Si 2 of an eutectic type

  17. Wear Characterization of Aluminium/Basalt Fiber Reinforced Metal Matrix Composites - A Novel Material

    Directory of Open Access Journals (Sweden)

    P. Amuthakkannan

    2017-06-01

    Full Text Available Aluminum alloy based metal matrix composite participate have a wider applications in wear resistance applications. Attempt made in current study is that, basalt fiber reinforced aluminum metal matrix composite have been prepared using stir casting method. Different weight percentage of basalt fiber reinforced with Al (6061 metal matrix composites are used to study the wear resistance of the composites. For wear study, percentage of reinforcement, normal load and sliding velocity are the considered as important parameters. To study the effect of basalt fiber reinforcement on the dry sliding wear of Al6061 alloy composites the Pin On wear tester is used. Initially hardness of the composites was tested, it was found that increasing reinforcement in the composite hardness value of the composites also increased. Based on the Grey relation analysis (GRA the effects of wear resistance of the composites were studied.

  18. Electron microscopy study of hardened layers structure at electrospark alloying the VT-18 titanium alloy with aluminium

    International Nuclear Information System (INIS)

    Pilyankevich, A.N.; Martynenko, A.N.; Verkhoturov, A.D.; Paderno, V.N.

    1979-01-01

    Presented are the results of metallographic, electron-microscopic, and X-ray structure analysis, of microhardness measurements and of the study of the electrode weight changes at electrospark alloying the VT-18 titanium alloy with aluminium. It is shown, that pulsating thermal and mechanical loadings in the process of electrospark alloying result in the electrode surface electroerosion, a discrete relief is being formed, which changes constantly in the process depending on the alloying time. Though with the process time the cathode weight gain increases, microareas of fracture in the hardened layer appear already at the initial stages of electrospark alloying

  19. Researches focused on structure of aluminium alloys processed by rapid solidification, used in automotive industry

    International Nuclear Information System (INIS)

    Sfat, C.; Vasile, T.; Vasilescu, M.

    2001-01-01

    The paper present some new results focused on an aluminium high temperature alloy, obtained by 'melt spinning method'. alloy composition, processing conditions, resulted structures and the influence between them are presented. There are studied the two zone structures of the alloy and the relation between processing conditions and the characteristics of the zones, with implications on mechanical behavior in real conditions. The final conclusion show that is possible to control the structure in order to improve material behavior. (author)

  20. Friction and corrosion resistance of sputter deposited supersaturated metastable aluminium-molybdenum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Zeid, O.A. [Univ. of the United Arab Emirates, Al-Ain (United Arab Emirates). Dept. of Mech. Eng.; Bates, R.I. [Design, Mfg. and Marketing Research Inst., Univ. of Salford (United Kingdom)

    1996-12-15

    Two closed field unbalanced magnetrons with targets of aluminium and molybdenum have been used for the co-deposition of aluminium-molybdenum coatings with different compositions. A pin on disk machine and a computer controlled potentiostat have been used to evaluate respectively, the tribological and corrosion properties of the deposited alloys. Results have shown that introducing molybdenum into aluminium coatings improves their poor tribological properties. Aluminium-molybdenum coatings with different compositions have shown low wear behaviour and for coatings with high molybdenum contents (> 80%) friction coefficients against steel, as low as 0.18 have been obtained. The addition of molybdenum into aluminium coatings has reduced their corrosion tendency and corrosion current density in a marine environment. (orig.)

  1. Heat transfer modeling in asymmetrical sheet rolling of aluminium alloys with ultra high shear strain

    Directory of Open Access Journals (Sweden)

    Pesin Alexander

    2016-01-01

    Full Text Available Asymmetrical sheet rolling is a method of severe plastic deformation (SPD for production of aluminium alloys with UFG structure. Prediction of sheet temperature during SPD is important. The temperature of sheet is changed due to the conversion of mechanical work into heat through sliding on contact surfaces and high shear strain. Paper presents the results of FEM simulation of the effect of contact friction, rolling speed and rolls speed ratio on the heating of aluminium sheets during asymmetrical rolling.

  2. Process for the manufacture of plates containing neutron poison from aluminium and aluminium alloys

    International Nuclear Information System (INIS)

    Bauer, G.; Pollmann, E.; Srostlik, P.

    1985-01-01

    A process for guaranteeing sub-critical arrangements of nuclear fuel in tranport and/or storage containers is described, in which a homogeneous distribution of neutron poison in the aluminium matrix is guaranteed. A homogeneous mixture of aluminium powder and neutron poison powder is produced, this is pressed into plates in several stages, dried and made into hollow aluminium profiles of rectangular cross-section. The open ends of the hollow profile are then closed and this is rolled to the required dimension at 470-500 0 C. (orig./HP) [de

  3. Reinforcement of 2124 Al alloy with low micron SiC and nano Al2O3 via solid-state forming

    CSIR Research Space (South Africa)

    Gxowa, Z

    2015-07-01

    Full Text Available A powder metallurgical process was used to fabricate Metal Matrix Composites (MMCs). A 2124 aluminium alloy was reinforced with 5 and 10 vol. % of Al2O3 (40-70nm) to form Metal Matrix Nano Composites (MMNCs) as well as 10 and 15 vol. % of SiC (1...

  4. Effect of aluminium on formation of metastable phases in titanium-niobium alloys

    International Nuclear Information System (INIS)

    Trenogina, T.L.; Derevyanko, V.N.; Vozilkin, V.A.

    2001-01-01

    Specific features of phase transformations in the alloy of Ti-20Nb-29Al (at.%) are investigated in comparison with those in the aluminium-free Ti-21Nb alloy. It is states that in the alloy Ti-20Nb-29Al on quenching the ordering of β-solid solution takes place with B2-structure formation. The B2-matrix experiences decomposition with the formation of ordered Ω 0 -phase which field ranges up to 700 deg C. The investigation results show that the sequence of phase formation in Ti-Nb-Al and aluminium-free alloys is much the same. The only difference between them is the formation of ordered phases in the alloy Ti-20Nb-29Al [ru

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    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 the local......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...

  6. An indirect method for determining phosphorus in aluminium alloys by atomic-absorption spectrometry.

    Science.gov (United States)

    Bernal, J L; Del Nozal, M A; Deban, L; Aller, A J

    1981-07-01

    An indirect method is described for the determination of phosphorus in aluminium alloys. Ammonium molybdate is added to a solution of the aluminium alloy and the molybdophosphoric acid formed is selectively extracted into n-butyl acetate. The twelve molybdenum atoms associated with each phosphate ion are determined by direct atomic-absorption spectrometry with the n-butyl acetate phase in a nitrous oxide-acetylene flame, with measurement at 313.2 nm. The most suitable conditions have been established and the effect of other ions has been studied.

  7. Quantitative assessment of Aluminium cast Alloys` structural parameters to optimize ITS properties

    Directory of Open Access Journals (Sweden)

    L. Kuchariková

    2017-01-01

    Full Text Available The present work deals with evaluation of eutectic Si (its shape, size, and distribution, dendrite cell size and dendrite arm spacing in aluminium cast alloys which were cast into different moulds (sand and metallic. Structural parameters were evaluated using NIS-Elements image analyser software. This software is imaging analysis software for the evaluation, capture, archiving and automated measurement of structural parameters. The control of structural parameters by NIS Elements shows that optimum mechanical properties of aluminium cast alloys strongly depend on the distribution, morphology, size of eute ctic Si and matrix parameters.

  8. Aluminium alloys welding with high-power Nd:YAG lasers

    International Nuclear Information System (INIS)

    Garcia Orza, J.A.

    1998-01-01

    Aluminium alloys have good mechanical properties (high strength-to-weight ratio, corrosion resistance) and good workability. their applications are growing up, specially in the transportation industry. Weldability is however poorer than in other materials; recent advances in high power YAG laser are the key to obtain good appearance welds and higher penetration, at industrial production rates. Results of the combination of high power YAG beams with small fiber diameters and specific filler wires are presented. It is also characterized the air bone particulate material, by-product of the laser process: emission rates, size distribution and chemical composition are given for several aluminium alloys. (Author) 6 refs

  9. Scanning and transmission electron microscopy study of the microstructural changes occurring in aluminium matrix composites reinforced with SiC particles during casting and welding: interface reactions

    Science.gov (United States)

    Urena; Gomez De Salazar JM; Gil; Escalera; Baldonedo

    1999-11-01

    Processing of aluminium matrix composites (AMCs), especially those constituted by a reactive system such as Al-SiC, presents great difficulties which limit their potential applications. The interface reactivity between SiC and molten Al generates an aluminium carbide which degrades the composite properties. Scanning and transmission electron microscopes equipped with energy-dispersive X-ray spectroscopes are essential tools for determining the structure and chemistry of the Al-SiC interfaces in AMCs and changes occurring during casting and arc welding. In the present work, an aluminium-copper alloy (AA2014) reinforced with three different percentages of SiC particles was subjected to controlled remelting tests, at temperatures in the range 750-900 degrees C for 10 and 30 min. Arc welding tests using a tungsten intert gas with power inputs in the range 850-2000 W were also carried out. The results of these studies showed that during remelting there is preferential SiC particle consumption with formation of Al4C3 by interface reaction between the solid SiC particle and the molten aluminium matrix. The formation of Al4C3 by the same mechanism has also been detected in molten pools of arc welded composites. However, in this case there was formation of an almost continuous layer of Al4C3, which protects the particle against further consumption, and formation of aciculate aluminium carbide on the top weld. Both are formed by fusion and dissolution of the SiC in molten aluminium followed by reaction and precipitation of the Al4C3 during cooling.

  10. Influence of the Mould Cooling Process on the Quality and Properties of Aluminium Alloy

    Directory of Open Access Journals (Sweden)

    Viktorie Weiss

    2014-12-01

    Full Text Available The article deals with the effect on the quality of casting moulds (metal, bentonite mixture on the structure of the alloy AlZn5,5MgCu and selected mechanical properties of the alloy. The effect of foundry moulds can significantly affect formation and range of crystal segregation and the subsequent thermal process of homogenization which has an influence on the final quality of the alloy. The research focuses on the formation and range of crystal segregation and its removal with homogenization annealing, in which the observed influence of individual factors influencing the diffusion process and quality of the aluminium alloy.

  11. Physical and chemical grounds of electrolytic fabrication of aluminium-strontium alloying composition

    International Nuclear Information System (INIS)

    Lysenko, A.P.

    1998-01-01

    It was revealed via study of literature sources that usage of alloying composition of strontium (not of sodium) is more expedient in modification of silumin-type alloys. In this case modification effect is keeping during long holdings and in repeated meltings. Electrolytic decomposition of strontium chloride with usage of liquid aluminium cathode is the most simple and cheap method for fabrication of alloying composition. The operation scheme for production of Al-Sr alloy was proposed in this work on the base of thermodynamic analysis

  12. Study of fatigue behaviour of 7475 aluminium alloy

    Indian Academy of Sciences (India)

    Unknown

    controlled toughness alloy developed for applications that require a combination of high strength, superior fracture toughness and resistance to fatigue crack propagation both in air and aggressive environment. The 7475 alu- minium alloy is basically a modified version of 7075 alloy. Properties in 7075 alloy are improved by ...

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

    CERN Document Server

    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.

  14. Laser surface alloying of aluminium with WC+Co+NiCr for improved wear resistance

    CSIR Research Space (South Africa)

    Nath, S

    2012-03-01

    Full Text Available Department of Metallurgical & Materials Engineering, IIT Kharagpur, West Bengal, India 2National Laser Centre, CSIR, Pretoria, South Africa Abstract In the present study, laser surface alloying of aluminium with WC+Co+NiCr (in the ratio of 70... be used for dispersion of ceramic materials into metallic matrix and hence, form a ceramic dispersed metal matrix composite on metallic substrate [3]. The advantages of laser surface alloying include refinement of the microstructure, uniform dispersion...

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

    International Nuclear Information System (INIS)

    Zhou, X.; Luo, C.; Hashimoto, T.; Hughes, A.E.; Thompson, G.E.

    2012-01-01

    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.

  16. Laser welding of SSM Cast A356 aluminium alloy processed with CSIR-Rheo technology

    CSIR Research Space (South Africa)

    Akhter, R

    2006-01-01

    Full Text Available Samples of aluminium alloy A356 were manufactured by Semi Solid Metals HPDC technology, developed recently in CSIR, Pretoria. They were butt welded in as cast conditions using as Nd: YAG laser. The best metal and weld microstructure were presented...

  17. Corrosion behaviour of 6063 aluminium alloy in acidic and in alkaline media

    Directory of Open Access Journals (Sweden)

    Prabhu Deepa

    2017-05-01

    Full Text Available The corrosion behaviour of 6063 aluminium alloy was investigated in different concentrations of phosphoric acid medium and sodium hydroxide medium at different temperatures. The study was done by electrochemical method, using Tafel polarization technique and electrochemical impedance spectroscopy (EIS technique. The surface morphology was investigated using scanning electron microscope (SEM with Energy-dispersive X-ray spectroscopy (EDX. The results showed that the 6063 aluminium alloy undergoes severe corrosion in sodium hydroxide medium than in phosphoric acid medium. The corrosion rate of 6063 aluminium alloy increased with an increase in the concentration of acid as well as with alkali. The corrosion rate was increased with an increase in temperature. The kinetic parameters and thermodynamic parameters were calculated using Arrhenius theory and transition state theory. Suitable mechanism was proposed for the corrosion of 6063 aluminium alloy in phosphoric acid medium and sodium hydroxide medium. The results obtained by Tafel polarization and electrochemical impedance spectroscopy (EIS techniques were in good agreement with each other.

  18. Ductile failure in upsetting of a rapid-solidification-processed aluminium alloy

    NARCIS (Netherlands)

    Habraken, F.A.C.M.; Dautzenberg, J.H.

    1993-01-01

    Cold upset-tests have been performed on a Rapid Solidification Processed (RSP) aluminium-alloy, produced by the ‘melt-spun ribbons’-process out of 70% car-scrap and 30% primary scrap. The ribbons are hot extruded, resulting in 29 mm diameter bar. Its properties regarding plastic flow and fracture

  19. Improvement of hardness of aluminium AA1200 by laser surface alloying

    CSIR Research Space (South Africa)

    Mabhali, Luyolo AB

    2010-07-01

    Full Text Available Aluminium is vastly used in industry due to its low cost, light weight and excellent workability, but lacks in wear resistance and hardness. Laser alloying is used to improve the surface properties such as hardness by modifying the composition...

  20. Anti-corrosive Conversion Coating on Aluminium Alloys Using High Temperature Steam

    DEFF Research Database (Denmark)

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

    or convert to a functional conversion coating. In the last several decades chromate conversion coating (CrCCs) have been the most common conversion coatings used for aluminium alloys. Due to the toxicity of the hexavalent chrome, however, environmental friendly alternatives to CrCCs have been investigated...

  1. Steam assisted oxide growth on aluminium alloys using oxidative chemistries: Part I Microstructural investigation

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Piotrowska, Kamila; Gudla, Visweswara Chakravarthy

    2015-01-01

    The surface treatment of aluminium alloys under steam containing KMnO4 and HNO3resulted in the formation of an oxide layer having a thickness of up to 825 nm. The use of KMnO4 and HNO3 in the steam resulted in incorporation of the respective chemical species into the oxide layer. Steam treatment ...

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

    Czech Academy of Sciences Publication Activity Database

    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 alloys * small cracks * grack growth rate Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.799, year: 2010

  3. Property enhancement by grain refinement of zinc-aluminium foundry alloys

    International Nuclear Information System (INIS)

    Krajewski, W K; Piwowarski, G; Krajewski, P K; Greer, A L

    2016-01-01

    Development of cast alloys with good mechanical properties and involving less energy consumption during their melting is one of the key demands of today's industry. Zinc foundry alloys of high and medium Al content, i.e. Zn-(15-30) wt.% Al and Zn-(8-12) wt.% Al, can satisfy these requirements. The present paper summarizes the work [1-9] on improving properties of sand-cast ZnAl10 (Zn-10 wt.% Al) and ZnAl25 (Zn-25 wt. % Al) alloys by melt inoculation. Special attention was devoted to improving ductility, whilst preserving high damping properties at the same time. The composition and structural modification of medium- and high-aluminium zinc alloys influence their strength, tribological properties and structural stability. In a series of studies, Zn - (10-12) wt. % Al and Zn - (25-26) wt.% Al - (1-2.5) wt.% Cu alloys have been doped with different levels of added Ti. The melted alloys were inoculated with ZnTi-based refiners and it was observed that the dendritic structure is significantly finer already after addition of 50 - 100 ppm Ti to the melted alloys. The alloy's structure and mechanical properties have been studied using: SEM (scanning electron microscopy), LM (light microscopy), dilatometry, pin-on-disc wear, and tensile strength measurements. Grain refinement leads to significant improvement of ductility in the binary high-aluminium Zn-(25-27) Al alloys while in the medium-aluminium alloys the effect is rather weak. In the ternary alloys Zn-26Al-Cu, replacing a part of Cu with Ti allows dimensional changes to be reduced while preserving good tribological properties. Furthermore, the high initial damping properties were nearly entirely preserved after inoculation. The results obtained allow us to characterize grain refinement of the examined high-aluminium zinc alloys as a promising process leading to the improvement of their properties. At the same time, using low melting ZnTi-based master alloys makes it possible to avoid the excessive melt

  4. Features of argon-arc welding of aluminium alloy AD1 to stainless steel 12Kh18N10T

    International Nuclear Information System (INIS)

    Sadov, I.I.

    1982-01-01

    Welding of pipes made of the 12Kh18N10T stainless steel and the AD1 aluminium alloy is proposed to perform using one-sided aluminizing. It is recommended to use shields in order to protect internal and external surfaces of pipes, aluminizing of which is impossible. It is shown that developed technological process for welded joints made of aluminium and stainless steel for cryogenic apparatus permits to create light-duty cryostat assembly using aluminium alloys instead of copper alloys, to increase reliability of apparatus (usage of welded joints instead of soldered ones), and to improve labour conditions

  5. Microstructure and mechanical properties of laser treated aluminium alloys

    NARCIS (Netherlands)

    deHosson, JTM; vanOtterloo, LDM; Noordhuis, J; Mazumder, J; Conde, O; Villar, R; Steen, W

    1996-01-01

    Al-Cu alloys and an Al-Cu-Mg alloy, Al 2024-T3, were exposed to laser treatments at various scan velocities. In this paper the microstructural features and mechanical properties are reported. As far as the mechanical property of the Al-Cu-Mg alloy is concerned a striking observation is a minimum in

  6. Diamond turning and polishing tests on new RSP aluminium alloys

    NARCIS (Netherlands)

    Horst, R. ter; Haan, M. de; Gubbels, G.P.H.; Senden, R.; Venrooy, B.W.H. van; Hoogstrate, A.M.

    2012-01-01

    For years now conventional aluminium 6061 T6 has widely been used for mirrors in astronomical instruments, being diamond turned or since a few years also being optically polished. This allows the development of optical systems that can be tested and operated at any temperature, without being

  7. Elaboration in the area of aluminium containing alloys

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.

    2002-01-01

    In the Institute of Chemistry was elaborated the experimental-industrial installation and technology of deep aluminium purification by the methods of zone melting and recrystallization. The developed technology let receive the metal of model A5 N A6 N dependence from number of induction zone passage

  8. Cavitation-aided grain refinement in aluminium alloys

    NARCIS (Netherlands)

    Atamanenko, T.V.

    2010-01-01

    This thesis deals with grain refinement under the influence of ultrasonic-driven cavitation in aluminium casting processes. Three major goals of this research were: (1) to identify the mechanism of the cavitation-aided grain refinement at different stages of solidification; (2) to reveal the

  9. Recovery of tritium from lithium-sintered aluminium product (SAP) and lithium-aluminium alloys

    International Nuclear Information System (INIS)

    Talbot, J.B.; Wiffen, F.W.

    1979-01-01

    The tritium release rates of irradiated samples of lithium-containing aluminium (Li-Al) and sintered aluminium product (Li-SAP) were investigated to evaluate the potential application of both materials in fusion reactors. The observed release rates followed the pattern expected for bulk diffusion of tritium in a solid. Therefore, diffusion coefficients for tritium in Li-SAP were determined over a temperature range of 383 and 500 0 C and tritium in Li-Al at 450 0 C. At 450 0 C, the diffusion coefficients of tritium in Li-SAP and Li-Al are 2.988 x 10 -10 cm 2 sec -1 and 1.462 x 10 -6 cm 2 sec -1 , respectively. (author)

  10. Recovery of aluminium, nickel-copper alloys and salts from spent fluorescent lamps.

    Science.gov (United States)

    Rabah, Mahmoud A

    2004-01-01

    This study explores a combined pyro-hydrometallurgical method to recover pure aluminium, nickel-copper alloy(s), and some valuable salts from spent fluorescent lamps (SFLs). It also examines the safe recycling of clean glass tubes for the fluorescent lamp industry. Spent lamps were decapped under water containing 35% acetone to achieve safe capture of mercury vapour. Cleaned glass tubes, if broken, were cut using a rotating diamond disc to a standard shorter length. Aluminium and copper-nickel alloys in the separated metallic parts were recovered using suitable flux to decrease metal losses going to slag. Operation variables affecting the quality of the products and the extent of recovery with the suggested method were investigated. Results revealed that total loss in the glass tube recycling operation was 2% of the SFLs. Pure aluminium meeting standard specification DIN 1712 was recovered by melting at 800 degrees C under sodium chloride/carbon flux for 20 min. Standard nickel-copper alloys with less than 0.1% tin were prepared by melting at 1250 degrees C using a sodium borate/carbon flux. De-tinning of the molten nickel-copper alloy was carried out using oxygen gas. Tin in the slag as oxide was recovered by reduction using carbon or hydrogen gas at 650-700 degrees C. Different valuable chloride salts were also obtained in good quality. Further research is recommended on the thermodynamics of nickel-copper recovery, yttrium and europium recovery, and process economics.

  11. Recovery of actinides from actinide-aluminium alloys by chlorination: Part I

    Energy Technology Data Exchange (ETDEWEB)

    Cassayre, L., E-mail: cassayre@chimie.ups-tlse.fr [Laboratoire de Genie Chimique (LGC), Departement Procedes Electrochimiques, CNRS-UMR 5503, Universite de Toulouse III - Paul Sabatier, 31062 Toulouse (France); Soucek, P.; Mendes, E.; Malmbeck, R.; Nourry, C.; Eloirdi, R.; Glatz, J.-P. [European Commission, JRC, Institute for Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany)

    2011-07-01

    Pyrochemical processes in molten LiCl-KCl are being developed in ITU for recovery of actinides from spent nuclear fuel. The fuel is anodically dissolved to the molten salt electrolyte and actinides are electrochemically reduced on solid aluminium cathodes forming solid actinide-aluminium alloys. A chlorination route is being investigated for recovery of actinides from the alloys. This route consists in three steps: Vacuum distillation for removal of the salt adhered on the electrode, chlorination of the actinide-aluminium alloys by chlorine gas and sublimation of the formed AlCl{sub 3}. A thermochemical study showed thermodynamic feasibility of all three steps. On the basis of the conditions identified by the calculations, experiments using pure UAl{sub 3} alloy were carried out to evaluate and optimise the chlorination step. The work was focused on determination of the optimal temperature and Cl{sub 2}/UAl{sub 3} molar ratio, providing complete chlorination of the alloy without formation of volatile UCl{sub 5} and UCl{sub 6}. The results showed high efficient chlorination at a temperature of 150 deg. C.

  12. Recovery of aluminium, nickel-copper alloys and salts from spent fluorescent lamps

    International Nuclear Information System (INIS)

    Rabah, Mahmoud A.

    2004-01-01

    This study explores a combined pyro-hydrometallurgical method to recover pure aluminium, nickel-copper alloy(s), and some valuable salts from spent fluorescent lamps (SFLs). It also examines the safe recycling of clean glass tubes for the fluorescent lamp industry. Spent lamps were decapped under water containing 35% acetone to achieve safe capture of mercury vapour. Cleaned glass tubes, if broken, were cut using a rotating diamond disc to a standard shorter length. Aluminium and copper-nickel alloys in the separated metallic parts were recovered using suitable flux to decrease metal losses going to slag. Operation variables affecting the quality of the products and the extent of recovery with the suggested method were investigated. Results revealed that total loss in the glass tube recycling operation was 2% of the SFLs. Pure aluminium meeting standard specification DIN 1712 was recovered by melting at 800 deg. C under sodium chloride/carbon flux for 20 min. Standard nickel-copper alloys with less than 0.1% tin were prepared by melting at 1250 deg. C using a sodium borate/carbon flux. De-tinning of the molten nickel-copper alloy was carried out using oxygen gas. Tin in the slag as oxide was recovered by reduction using carbon or hydrogen gas at 650-700 deg. C. Different valuable chloride salts were also obtained in good quality. Further research is recommended on the thermodynamics of nickel-copper recovery, yttrium and europium recovery, and process economics

  13. Recovery of actinides from actinide-aluminium alloys by chlorination: Part I

    International Nuclear Information System (INIS)

    Cassayre, L.; Soucek, P.; Mendes, E.; Malmbeck, R.; Nourry, C.; Eloirdi, R.; Glatz, J.-P.

    2011-01-01

    Pyrochemical processes in molten LiCl-KCl are being developed in ITU for recovery of actinides from spent nuclear fuel. The fuel is anodically dissolved to the molten salt electrolyte and actinides are electrochemically reduced on solid aluminium cathodes forming solid actinide-aluminium alloys. A chlorination route is being investigated for recovery of actinides from the alloys. This route consists in three steps: Vacuum distillation for removal of the salt adhered on the electrode, chlorination of the actinide-aluminium alloys by chlorine gas and sublimation of the formed AlCl 3 . A thermochemical study showed thermodynamic feasibility of all three steps. On the basis of the conditions identified by the calculations, experiments using pure UAl 3 alloy were carried out to evaluate and optimise the chlorination step. The work was focused on determination of the optimal temperature and Cl 2 /UAl 3 molar ratio, providing complete chlorination of the alloy without formation of volatile UCl 5 and UCl 6 . The results showed high efficient chlorination at a temperature of 150 deg. C.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. An approach for continuous cooling transformation (CCT) diagrams of aluminium alloys

    International Nuclear Information System (INIS)

    Herding, T.; Kessler, O.; Hoffmann, F.; Mayr, P.

    2002-01-01

    Two different kinds of time temperature transformation (TTT) diagrams are known. The first one are isothermal transformation (IT) diagrams and the second one continuous cooling transformation (CCT) diagrams. These diagrams are important for the correct heat treatment of aluminium alloys, because they provide information about the required quenching rate, which is necessary to obtain a supersaturated solid solution during age hardening. Furthermore, it is possible to determine the lowest quenching rate, which permits both a high strength and a small distortion of the component after age hardening. In the literature IT diagrams for different aluminium alloys are available. To determine these diagrams, a solution annealing followed by quenching to defined temperatures is necessary. At these temperatures the alloy is kept isothermally until a transformation has started. These diagrams are not directly portable on continuous cooling, because of the different cooling paths. (orig.)

  16. Development of multilayer coatings for forming dies and tools of aluminium alloy from liquid state

    International Nuclear Information System (INIS)

    Torres, E; Ugues, D; Brytan, Z; Perucca, M

    2009-01-01

    In this work, a nanocomposite (Cr,Al) x N 1-x /Si 3 N 4 coating system was deposited on H11 hot work tool steel, using the Lateral Arc Rotating Cathodes (LARC (registered) ) deposition system and modulating the chemical composition of the chromium and aluminium-silicon content. Structural characterizations were performed using scanning electron microscopy, equipped with energy dispersive spectroscopy probe, and applying x-ray diffraction, for the evaluation of phase constitution and crystallite size. In addition to the structural features, the coatings' resistance to cyclic immersions in molten aluminium alloy was evaluated. The deposited CrAlSiN coatings exhibited an fcc-Cr 1-x Al x N type structure with different aluminium contents, which directly influence hardness and wear and fatigue resistance in cyclic immersion tests. The main failure modes that occurred on the coatings' surface were soldering and thermal fatigue cracks mainly in the form of heat checks. The aluminium rich coatings were able to withstand about 15 000 cycles, whereas the decrease in the aluminium content in the coatings results in a decrease in the resistance to the immersion in molten aluminium bath. It is worthwhile to note that uncoated H11, subjected to similar testing conditions, withstood at maximum 5000 cycles.

  17. High frequency ohmic loss of beryllium and its alloy with aluminium

    International Nuclear Information System (INIS)

    Prentslau, N.N.

    1999-01-01

    The surface resistance of Be of different purity and its alloy with Al (50%Be-50%Al) is investigated at temperatures ranged from 4,2 to 300 K in the 0-10 10 Hz frequency region. It is shown that within the temperature range (in the vicinity of 77 K) where beryllium is a de hyper conductor. Its surface resistance and the surface resistance of the alloy are minimum compared to that of other metals, in particular, of aluminium. The temperature dependence of the surface resistance of Be and its alloys is well described by the classical formulae of electrodynamics

  18. Summary of structural refinement in hi-silicon aluminium piston alloy with phosphorous as grain refiner

    International Nuclear Information System (INIS)

    Malik, F.A.; Sheikh, S.T.; Choudhry, A.A.

    2003-01-01

    Aluminium Silicon Alloys are extensively used in a wide variety of applications. There are numerous variables in composition, production control, final structure which can influence the mechanical properties of Hi - Silicon Piston alloys. Hypereutectic AlSi alloys develop coarse grain primary silicon crystals, which have a strong negative effect on the tensile strength, the ductility, and the hardness. These crystals slow machining and reduce the tool life considerably. Phosphorous addition produce a fine, evenly spread crystal structure, lamellar structure of the silicon changes into a granular structure. (author)

  19. Investigation of photocatalytic activity of titanium dioxide coating deposited on aluminium alloy substrate by plasma technique

    DEFF Research Database (Denmark)

    Daviðsdóttir, Svava; Soyama, Juliano; Dirscherl, Kai

    2011-01-01

    . Literature consists of large number of publications on titanium dioxide coating for self-cleaning applications, with glass as the main substrate. Only little work is available on TiO2 coating of metallic alloys used for engineering applications. Engineering materials, such as light-weight aluminium and steel...... have wide spread technological applications, where a combination of self-cleaning properties has a huge business potential. The results presented in this paper demonstrate superior photocatalytic properties of TiO2 coated aluminium compared to nano-scale TiO2 coating on glass substrate. The thickness...

  20. Effect of composition on the superplasticity of aluminium scandium alloys

    International Nuclear Information System (INIS)

    Bradley, E.L. III; Morris, J.W. Jr.

    1992-01-01

    Several aluminum alloys have been shown to exhibit superplasticty in the as-rolled condition. Previous work has shown that aluminum-scandium alloys also exhibit this behavior, but only with the addition of ternary alloying elements such as lithium and magnesium. These additions raised the strain-rate sensitivity of these alloys to 0.4-0.5 for selected strain rates at temperatures above 400 degrees C. A systematic study was undertaken of five Al-Sc alloys with varying lithium and magnesium concentrations in order to fully characterize the high temperature deformation mechanism. Specimens were deformed at a constant strain rate to predetermined true strains for textural and microstructural characterization. In this paper work is presented that will elucidate the effect of these different ternary additives on the superplastic deformation mechanism in these alloys

  1. Development of new ferritic alloys reinforced by nano titanium nitrides

    International Nuclear Information System (INIS)

    Mathon, M.H.; Perrut, M.; Poirier, L.; Ratti, M.; Hervé, N.; Carlan, Y. de

    2015-01-01

    Nano-reinforced steels are considered for future nuclear reactors or for application at high temperature like the heat exchangers tubes or plates. Oxide Dispersion Strengthened (ODS) alloys are the most known of the nano-reinforced alloys. They exhibit high creep strength as well as high resistance to radiation damage. This article deals with the development of new nano reinforced alloys called Nitride Dispersed Strengthened (NDS). Those are also considered for nuclear applications and could exhibit higher ductility with a simplest fabrication way. Two main fabrication routes were studied: the co-milling of Fe–18Cr1W0.008N and TiH 2 powders and the plasma nitration at low temperature of a Fe–18Cr1W0.8Ti powder. The materials were studied mainly by Small Angle Neutron Scattering. The feasibility of the reinforcement by nano-nitride particles is demonstrated. The final size of the nitrides can be similar (few nanometers) to the nano-oxides observed in ODS alloys. The mechanical properties of the new NDS show an amazing ductility at high temperature for a nano-reinforced alloy

  2. Development of new ferritic alloys reinforced by nano titanium nitrides

    Energy Technology Data Exchange (ETDEWEB)

    Mathon, M.H., E-mail: marie-helene.mathon@cea.fr [Laboratoire Léon Brillouin, CEA-CNRS, CEA/Saclay, 91191 Gif-sur-Yvette (France); Perrut, M., E-mail: mikael.perrut@onera.fr [Laboratoire Léon Brillouin, CEA-CNRS, CEA/Saclay, 91191 Gif-sur-Yvette (France); Poirier, L., E-mail: poirier@nitruvid.com [Bodycote France and Belgium, 9 r Jean Poulmarch, 95100 Argenteuil (France); Ratti, M., E-mail: mathieu.ratti@snecma.fr [CEA, DEN, Service de Recherches Métallurgiques Appliquées, F91191 Gif-sur-Yvette (France); Hervé, N., E-mail: nicolas.herve@cea.fr [CEA, DRT, LITEN, F38054 Grenoble (France); Carlan, Y. de, E-mail: yann.decarlan@cea.fr [CEA, DEN, Service de Recherches Métallurgiques Appliquées, F91191 Gif-sur-Yvette (France)

    2015-01-15

    Nano-reinforced steels are considered for future nuclear reactors or for application at high temperature like the heat exchangers tubes or plates. Oxide Dispersion Strengthened (ODS) alloys are the most known of the nano-reinforced alloys. They exhibit high creep strength as well as high resistance to radiation damage. This article deals with the development of new nano reinforced alloys called Nitride Dispersed Strengthened (NDS). Those are also considered for nuclear applications and could exhibit higher ductility with a simplest fabrication way. Two main fabrication routes were studied: the co-milling of Fe–18Cr1W0.008N and TiH{sub 2} powders and the plasma nitration at low temperature of a Fe–18Cr1W0.8Ti powder. The materials were studied mainly by Small Angle Neutron Scattering. The feasibility of the reinforcement by nano-nitride particles is demonstrated. The final size of the nitrides can be similar (few nanometers) to the nano-oxides observed in ODS alloys. The mechanical properties of the new NDS show an amazing ductility at high temperature for a nano-reinforced alloy.

  3. Laser beam welding of high strength aluminium-lithium alloys; Laserstrahlschweissen von hochfesten Aluminium-Lithium Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Enz, Josephin

    2012-07-01

    The present development in aircraft industry determined by the demand for a higher cost-effectiveness. Laser beam welding is one of the most promising joining technologies for the application in the aircraft industry through the considerable reduction of the production costs. Furthermore the weight of an aircraft structure can be reduced by the use of light and high strength aluminium alloys. This paper deals with the development of a process for the laser beam welding of a skin-stringer-joint where the Al-Li-alloy AA2196 is used as stringer material and the Al-Li-alloy AA2198 is used as skin and stringer material. By the use of design of experiments the optimal welding process parameters for different material combinations were determined which will be used for the welding of a 5-stringer panel. Therefore the weld seams of the joints were tested for irregularities and microstructural characteristics. In addition several mechanical tests were performed, which define the quality of the welded joint. Furthermore the influence of the oxide layer and the welding preparation on the welding performance was investigated. (orig.) [German] Die derzeitigen Entwicklungen im Flugzeugbau werden durch die allgemeine Forderung nach einer Steigerung der Wirtschaftlichkeit bestimmt. Das Laserstrahlschweissen ist dabei eines der vielversprechendsten Fuegeverfahren fuer die Anwendung im Flugzeugbau durch das die Herstellungskosten deutlich reduziert werden koennen. Zudem kann durch die Verwendung von leichten und hochfesten Aluminium-Legierungen das Gewicht einer Flugzeugstruktur zusaetzlich reduziert werden. Die vorliegende Arbeit befasst sich mit der Entwicklung eines Prozesses zum Laserstrahlschweissen einer Skin-Stringer-Verbindung aus den Aluminium-Lithium-Legierungen AA2196 (als Stringer-Werkstoff) und AA2198 (als Skin- und Stringer-Werkstoff). Unter Verwendung der statistischen Versuchsplanung wurden die optimalen Einstellungen der Schweissprozessparameter fuer die

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

    International Nuclear Information System (INIS)

    Bataillon, Christian

    1987-01-01

    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 [fr

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

    International Nuclear Information System (INIS)

    Elangovan, K.; Balasubramanian, V.; Babu, S.

    2009-01-01

    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

  6. Mechanical properties of aluminium-uranium alloy and aluminium commercially pure at several temperatures

    International Nuclear Information System (INIS)

    Quadros, N.F. de.

    1976-01-01

    The mechanical properties of Ai-U (18,4 wt %) alloy with and without heat treatment were determined, and they were compared with the mechanical properties of aluminum alloy of commercial purity, AI-1100, at tempiratures of 25, 500, 550 and 600 0 C, the changes of both the yield point stress and the ultimate tensile strength as a function of temperature may be described through two emperical relationships. A fractography study was also made [pt

  7. Phase composition and properties of rapidly cooled aluminium-zirconium-chromium alloys

    International Nuclear Information System (INIS)

    Sokolovskaya, E.M.; Badalova, L.M.; Podd''yakova, E.I.; Kazakova, E.F.; Loboda, T.P.; Gribanov, A.V.

    1989-01-01

    Using the methods of physicochemical analysis the interaction of aluminium with zirconium and chromium is studied. Polythermal cross sections between Al 3 -Zr-Al 7 Cr and radial polythermal cross section from aluminium-rich corner with the ratio of components Zr:Cr=5:7 by mass are constructed. The effect of zirconium and chromium content on electrochemical characteristics of aluminium-base rapidly quenching alloys in systems Al-Cr, Al-Zr, Al-Cr-Zr. An increase in chromium concentration in oversaturated solid solution of Al-Cr system expands considerably the range of passive state. When Al 7 Cr phase appears the range of passive stae vanishes

  8. Joining of Aluminium Alloy and Steel by Laser Assisted Reactive Wetting

    Science.gov (United States)

    Liedl, Gerhard; Vázquez, Rodrigo Gómez; Murzin, Serguei P.

    2018-03-01

    Compounds of dissimilar materials, like aluminium and steel offer an interesting opportunity for the automotive industry to reduce the weight of a car body. Thermal joining of aluminium and steel leads to the formation of brittle intermetallic compounds, which negatively affects the properties of the welded joint. Amongst others, growth of such intermetallic compounds depends on maximum temperature and on the time at certain temperatures. Laser welding with its narrow well seam and its fast heating and cooling cycles provides an excellent opportunity to obtain an ultrathin diffusion zone. Joining of sheet metal DC01 with aluminium alloy AW6016 has been chosen for research. The performed experimental studies showed that by a variation of the beam power and scanning speed it is possible to obtain an ultrathin diffusion zone with narrow intermetallic interlayers. With the aim of supporting further investigation of laser welding of the respective and other dissimilar pairings a multi-physical simulation model has been developed.

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

    International Nuclear Information System (INIS)

    Andreeva, V.V.; Alekseeva, E.L.; Dontsov, S.N.; Moiseeva, I.S.

    The mechanical properties and corrosion resistance of niobium--titanium--aluminum alloys in 20 percent HCl and 40--75 percent H 2 SO 4 at 40 and 100 0 C are considered. Current density vs potential and corrosion rate vs potential potentiostatic curves plotted in 75 percent H 2 SO 4 at 140 0 C 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 H 2 SO 4 at 140 0 C is an exponential function of the atomic content of the alloying components (Ti, Al) in them; aluminum vitiates the corrosion resistance very strongly

  10. Fracture Toughness and Shear Strength of the Bonded Interface Between an Aluminium Alloy Skin and a FRP Patch

    Science.gov (United States)

    Kumar, Prashant; Shinde, Prakash Sonyabapu; Bhoyar, Gaurav

    2018-05-01

    The existing techniques to determine the fracture properties such as critical energy release rate in mode I (GIc) and mode II (GIIc) of an interface between two sheets of same material were modified to determine these properties between the sheets of dissimilar materials and thickness. In addition, the interface shear strength (ISS) was also determined. Experiments were carried out on the specimens made of a pre-cracked thin aluminium alloy skin and a Fiber reinforced polymer (FRP) patch. Two kinds of surface preparation of the aluminium skin were employed; (i) emery-paper roughened surface (ERS) and (ii) Sodium Hydroxide (NaOH) treated surface (NTS). GIc of ERS specimen was found to be 36.1 J/m2, while it was found to be much higher for NTS specimens, that is, 87.3 J/m2. GIIc was found to be 282.4 J/m2 for ERS specimens and much higher as 734.5 J/m2 for NTS specimens. ISS was determined as 32.6 MPa for ERS specimen and significantly higher for NTS specimen, that is, 44.5 MPa. The micrographs obtained from a field emission-scanning electron microscope (FE-SEM) and the surface roughness test showed that the NTS was significantly rougher than the ERS, explaining the higher values of all the three kinds of NTS specimens.

  11. Determination of initial stages of recrystallization in aluminium alloys by X-ray diffraction

    International Nuclear Information System (INIS)

    Loew, Marjorie

    2000-01-01

    Aluminium is a metal with a wide variety of application, such as beer cans, pans, door and window borders, and others more advanced, such as airplane structure, car engines, nuclear reactors components, rocket propulsion components and so on. Most of aluminium application is in alloy form. Such alloys must present suitable mechanical and chemical properties that are obtained, not entirely, by microstructure development. In this work, the beginning of recrystallization processes of AA1050 and AA3003 aluminium alloys were studied using X-ray diffraction techniques, transmission electron microscopy and hardness test. For such a sample, an initial heat treatment was done in order to homogenize the samples microstructure, followed by cold rolling and submitted again to a heat treatment in different temperatures in a hot furnace. After that samples were analyzed to verify the beginning of the recrystallization. Vickers hardness test revealed that the beginning of recrystallization is between 150 and 300 deg C for 1050 aluminium alloy and 200 and 300 deg C for 3003 aluminium alloy. X-ray diffraction using transmission chamber showed that the beginning of recrystallization is 240 and 260 deg C for AA1050 and AA3003, respectively. These temperatures were determined as the diffraction patterns recorded in the photographic plates changes when the recrystallization takes place. In this way, the deformed sample shows continuous concentric lines and the beginning of recrystallization is characterized by the occurrence of defined spots in this pattern. The Pole Figures goniometric method revealed that the beginning of recrystallization takes place between 250 and 300 deg C for both alloys. In the same way, orientation distribution functions showed the same temperature range for the recrystallization. However, the analysis by α and β fiber figures, the recrystallization temperatures are 240 and 260 deg C for AA1050 and AA3003, respectively. Finally, after the analysis of all

  12. First results on nitriding aluminium alloys in a low-pressure RF plasma

    International Nuclear Information System (INIS)

    Fewell, M.P.; Priest, J.M.; Collins, G.A.; Short, K.T.

    2000-01-01

    Full text: Aluminium alloys are now well established as materials of choice for many commercial applications, especially where strength-to-weight ratio is a critical parameter. However, their more widespread use is inhibited by their low surface hardness. For steels, similar problems can be overcome by nitriding. The nitrogen-rich surface layer has high hardness and load-bearing capacity, and is very well bonded to the substrate. The development of a similar surface-treatment process for aluminium alloys is clearly a desirable goal. It is therefore not surprising that many research groups worldwide have attempted to nitride aluminium. Much of this work studied pure aluminium, a material of no interest for structural applications. Previous investigations into nitriding aluminium alloys' had indifferent results. However, they have served to identify the key issues, which are the importance of a pre-cleaning steps to remove the surface oxide, of impurity control during the nitriding and the desirability of using as low a process temperature as possible. In all of these areas, our process using a low-pressure RF plasma is likely to be competitive. In view of this, we have undertaken a comparative study of a range of commercially available aluminium alloys. All treatments were carried out in the hot-wall nitriding reactor at ANSTO. The samples consist of disks 25mm in diameter and ∼3mm thick which were polished and ultrasonically cleaned in alcohol prior to treatment. The samples were stored in air at all times except when in the nitriding reactor. In a series of treatments, the treatment time was varied in the range 1-16 h and the temperature in the range 350-500 deg C. All treatments were preceeded by a plasma cleaning step in a H 2 /50%Ar mixture for a duration of 1.5-2.0 h while the reactor reached processing temperature. The treatments all used pure N 2 at a pressure of 0.4Pa and a nitrogen flow rate of 12μmol s -1 , with 245W of rf power at 13.56MHz applied to

  13. Fabrication of tungsten wire reinforced nickel-base alloy composites

    Science.gov (United States)

    Brentnall, W. D.; Toth, I. J.

    1974-01-01

    Fabrication methods for tungsten fiber reinforced nickel-base superalloy composites were investigated. Three matrix alloys in pre-alloyed powder or rolled sheet form were evaluated in terms of fabricability into composite monotape and multi-ply forms. The utility of monotapes for fabricating more complex shapes was demonstrated. Preliminary 1093C (2000F) stress rupture tests indicated that efficient utilization of fiber strength was achieved in composites fabricated by diffusion bonding processes. The fabrication of thermal fatigue specimens is also described.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Mechanical properties and corrosion behaviour of MIG welded 5083 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Durmus, Huelya [Celal Bayar Univ., Turgutlu-Manisa (Turkey)

    2011-07-01

    For this study 5083 Aluminium alloy plates, as used in automobiles and watercraft, were experimentally MIG welded. The plates were joined with different wires and at various currents. The effects of welding with different parameters on the mechanical and corrosion properties were investigated. The corrosion behaviour of the MIG welded 5083 Aluminium base material was also investigated. The effects of the chemical composition of the filler material on the mechanical properties were examined by metallographic inspection and tensile testing. By EDS and XRD analyses of specimens it turned out that different structures in the weld metal (Cu3Si) affect its mechanical properties. The mechanical properties of the specimens welded with 5356 filler metal were found as quite well improved as compared to those specimens welded with 4043 and 5183 filler material. The results of the metallographic analysis, and mechanical and corrosion tests exhibited that the 5356 filler material was most suitable for the 5083 Al alloy base material. (orig.)

  16. Composite Ni-Co-fly ash coatings on 5083 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Panagopoulos, C.N., E-mail: chpanag@metal.ntua.gr [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece); Georgiou, E.P.; Tsopani, A.; Piperi, L. [Laboratory of Physical Metallurgy, National Technical University of Athens, Zografos, 15780 Athens (Greece)

    2011-03-15

    Ni-Co-fly ash coatings were deposited on zincate treated 5083 wrought aluminium alloy substrates with the aid of the electrodeposition technique. Structural and chemical characterization of the produced composite 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-Co-fly ash coatings were found to consist of a crystalline Ni-Co solid solution with dispersed fly ash particles. In addition, chemical analysis of the Ni-Co matrix showed that it consisted of 80 wt.% Ni and 20 wt.% Co. The co-deposition of fly ash particles leads to a significant increase of the microhardness of the coating. The corrosion behaviour of the Ni-Co-fly ash/zincate coated aluminium alloy, in a 0.3 M NaCl solution (pH = 3.5), was studied by means of potentiodynamic corrosion experiments.

  17. Weld metal grain refinement of aluminium alloy 5083 through controlled additions of Ti and B

    Energy Technology Data Exchange (ETDEWEB)

    Schempp, Philipp; Rethmeier, Michael [Federal Institute for Materials Research and Testing BAM, Berlin (Germany). Div. ' ' Safety of Joined Components' ' ; Fraunhofer Institute for Production Systems and Design Technology IPK, Berlin (Germany). Dept. ' ' Joining and Coating Technology' ' ; Schwenk, Christopher; Cross, Carl Edward [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2011-07-01

    The refinement of the weld metal grain structure may lead to a significant change in its mechanical properties and in the weldability of the base metal. One possibility to achieve weld metal grain refinement is the inoculation of the weld pool. In this study, it is shown how additions of titanium and boron influence the weld metal grain structure of GTA welds of the aluminium alloy 5083 (Al Mg4.5Mn0.7). For this purpose, inserts consisting of base metal and additions of the master alloy Al Ti5B1 have been cast, deposited in the base metal and fused in a GTA welding process. The increase of the Ti and B content led to a significant decrease of the weld metal mean grain size and to a change in grain shape. The results provide a basis for a more precise definition of the chemical composition of commercial filler wires and rods for aluminium arc welding. (orig.)

  18. Analysing the strength of friction stir welded dissimilar aluminium alloys using Sugeno Fuzzy model

    Science.gov (United States)

    Barath, V. R.; Vaira Vignesh, R.; Padmanaban, R.

    2018-02-01

    Friction stir welding (FSW) is a promising solid state joining technique for aluminium alloys. In this study, FSW trials were conducted on two dissimilar plates of aluminium alloy AA2024 and AA7075 by varying the tool rotation speed (TRS) and welding speed (WS). Tensile strength (TS) of the joints were measured and a Sugeno - Fuzzy model was developed to interconnect the FSW process parameters with the tensile strength. From the developed model, it was observed that the optimum heat generation at WS of 15 mm.min-1 and TRS of 1050 rpm resulted in dynamic recovery and dynamic recrystallization of the material. This refined the grains in the FSW zone and resulted in peak tensile strength among the tested specimens. Crest parabolic trend was observed in tensile strength with variation of TRS from 900 rpm to 1200 rpm and TTS from 10 mm.min-1 to 20 mm.min-1.

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

    International Nuclear Information System (INIS)

    Staley, J.T.; Lege, D.J.

    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 extrusions for wings, and new monolithic and aluminum-fiber laminates for fuselages. Increase in fuel economy because of lighter weight structure is the driving force for aluminum alloys in the automotive market, and cost is extremely important. Mechanical properties for automotive use also depend on the application, and corrosion resistance must be adequate. For ''hang-on'' components such as fenders and hoods, formability is typically the limiting mechanical property. Strength must be adequate to resist denting at a thickness which offers cost-effective weight savings over steel. Because formability often decreases with increasing yield strength, alloys which are highly formable in the T4 temper and which age harden during the paint bake operation were developed. Alloys such as 6009 and 6010 are now being challenged by 2008, 6111 and 6016. Body structure components must be made from materials which absorb energy and fail gracefully during a crash. Such components for an automotive space frame are being die cast from an Al-Si-Mg alloy. These ductile die castings are joined to thin 6XXX extrusions which must combine formability, strength, ductility and the ability to deform plastically on impact. Bumpers must combine strength and adequate formability; in the event that current alloys are inadequate for future needs, a new 7XXX alloy offers an improved combination of properties. (orig.)

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Residual stress development and relief in high strength aluminium alloys using standard and retrogression thermal treatments

    OpenAIRE

    Robinson, J.S; Tanner, D.A

    2003-01-01

    peer-reviewed Residual stresses develop in the aluminium alloy 7010 when the material is quenched from the solution heat treatment temperature. Residual stress measurements have been made using the X-ray diffraction technique and a longitudinal split sawcut method to determine the magnitude of residual stress that develops in specimens sectioned from large open die forgings as a result of (a) quenching these specimens into water at different temperatures, and (b) cold water quenching from ...

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

    Czech Academy of Sciences Publication Activity Database

    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: 2.139, year: 2015 http://www.sciencedirect.com/science/article/pii/S0257897215303297

  3. Removal of chromium (VI) from water by micro-alloyed aluminium ...

    African Journals Online (AJOL)

    This paper deals with Cr(VI) ion removal from water, by micro-alloyed aluminium composite (MAlC), under flow conditions. In a water environment the MAlC acts as a strong reducing agent. Dissolving it in water is accompanied by the generation of Al(III) ions and reduction of water to H2, with OH- ions. The final product is ...

  4. Study of quality of nine aluminium alloys surfaces created using abrasiv waterjet

    Czech Academy of Sciences Publication Activity Database

    Klichová, Dagmar; Klich, Jiří; Gurková, Lucie

    2016-01-01

    Roč. 2016, March 2016 (2016), s. 892-895 ISSN 1805-0476 R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : abrasive waterjet * aluminium alloy * optical profilometer Subject RIV: JQ - Machines ; Tools http://www.mmscience.eu/content/file/archives/MM_Science_201608.pdf

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

    DEFF Research Database (Denmark)

    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...... pinning. The discrepancies between the experimental and theoretical results can be rationalised in terms of the limited nature of the physical effects modelled in the Zener analysis....

  6. High-Rate Compaction of Aluminium Alloy Foams

    International Nuclear Information System (INIS)

    Harrigan, J. J.; Hung, Y.-C.; Tan, P. J.; Bourne, N. K.; Withers, P. J.; Reid, S. R.; Millett, J. C. F.; Milne, A. M.

    2006-01-01

    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

  7. Corrosion resistant alloys for reinforced concrete [2009

    Science.gov (United States)

    2009-04-01

    Deterioration of concrete bridges because of reinforcing steel corrosion has been recognized for four-plus decades as a major technical and economic challenge for the United States. As an option for addressing this problem, renewed interest has focus...

  8. Corrosion resistant alloys for reinforced concrete [2007

    Science.gov (United States)

    2007-07-01

    Deterioration of concrete bridges because of reinforcing steel corrosion has been recognized for 4-plus decades as a major technical and economic challenge for the United States. As an option for addressing this problem, renewed interest has focused ...

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

    International Nuclear Information System (INIS)

    Solhan Yahya; Afidah Abdul Rahim; Affaizza Mohd Shah; Rohana Adnan

    2011-01-01

    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)

  10. Direct chill casting of aluminium alloys under electromagnetic interaction by permanent magnet assembly

    Science.gov (United States)

    Bojarevičs, Andris; Kaldre, Imants; Milgrāvis, Mikus; Beinerts, Toms

    2018-05-01

    Direct chill casting is one of the methods used in industry to obtain good microstructure and properties of aluminium alloys. Nevertheless, for some alloys grain structure is not optimal. In this study, we offer the use of electromagnetic interaction to modify melt convection near the solidification interface. Solidification under various electromagnetic interactions has been widely studied, but usually at low solidification velocity and high thermal gradient. This type of interaction may succeed fragmentation of dendrite arms and transport of solidification nuclei thus leading to improved material structure and properties. Realization of experimental small-scale crystallizer and electromagnetic system has been described in this article.

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

    DEFF Research Database (Denmark)

    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....

  12. Study on segregation of aluminium-uranium alloys

    International Nuclear Information System (INIS)

    Lima, Rui Marques de

    1979-01-01

    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 UAl 3 and UAl 4 phases with dendritic morphology. The dendritic UAl 3 , phase morphology was affected both by the solute concentration in the alloy and by the growth rate. The dendritic UAl 3 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

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Microstructural and electrochemical characterization of environmentally friendly conversion layers on aluminium alloys

    Directory of Open Access Journals (Sweden)

    Palomino Luis Enrique M.

    2003-01-01

    Full Text Available Cerium conversion layers (CeCL have been investigated as a replacement for chromium conversion layers to protect Al alloys against corrosion. In this work the microstructure and the electrochemical behaviour of aluminium alloy 2024 with and without CeCL were investigated using, respectively, SEM-EDX and EIS. EDX results have shown that the presence of dispersed plated Cu particles on the alloy surface enhances the formation of the CeCL increasing the intensity of Ce peaks in the EDX spectra. EIS measurements on conversion-coated samples have shown that the presence of the layer increases the impedance, and that its presence is detected by the presence of a high frequency time constant. Results of potentiodynamic experiments have shown that the corrosion protection afforded by the conversion layer is due to the hindrance of the oxygen reduction reaction and that the pitting potential of the alloy is not changed.

  15. Precipitation hardening of cast Zr-containing A356 aluminium alloy

    International Nuclear Information System (INIS)

    Baradarani, B.; Raiszadeh, R.

    2011-01-01

    The effect of small additions of zirconium on the hardness, grain size, precipitate type and size of cast A356 aluminium alloy was investigated. The cast alloys were solution treated and then artificially aged for different periods of time. Hardness tests and scanning electron microscope (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) studies were carried out on the as-cast, as-solutionised and age-hardened specimens. Incoherent, coarse Al 3 Zr particles formed in the microstructure during the solidification of the alloy and caused grain refinement in the as-cast structure. These particles dissolved and reprecipitated as smaller-size particles during the solution treatment, causing the hardness of the alloy to remain constant at high temperatures for long periods of time due to the slow diffusion of Zr in the α-Al.

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

    International Nuclear Information System (INIS)

    Nguyen, Chuong L.; Atanacio, Armand; Zhang, Wei; Prince, Kathryn E.; Hyland, Margaret M.; Metson, James B.

    2009-01-01

    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.

  17. Pitting by corrosion in aluminium and Al-6201 alloy

    International Nuclear Information System (INIS)

    Vera, R.; Schrebler, R.; Layana, G.; Orellana, F.; Olguin, A.

    1998-01-01

    The susceptibility of pure aluminum 6201 alloy to pitting was investigated in sodium chloride solutions through determination of the corrosion, repassivation and pitting potentials. Potentiodynamic polarization including scratching techniques were employed being also determined the type and relative amount of corrosion damage to the metals. The morphology of the attach was determined using scanning electrons microscopy (SEM). The results showed a similar performance for aluminum 6201 alloy and aluminum. It was also observed that an increase in chloride concentration resulted in a decrease in the corrosion, pitting and repassivation potentials of both materials. (Author) 19 refs

  18. Improving the casting properties of high-strength aluminium alloys:

    OpenAIRE

    Ekrt, Ondřej; Šerák, Jan; Vojtěch, Dalibor

    2004-01-01

    Al-Zn-Mg-Cu alloys are examples of high-strength alloys. After age-hardening they often possess tensile strengths of more than 500 MPa. However, their casting properties are relatively poor as a result of solidification intervals that are too wide. Therefore, they often require an extrusion, rolling, or forging treatment, and the production of small series of special parts can, as a consequence, be very expensive. In this study, an improvement in the castability and a reduction of the hot-tea...

  19. Microstructure and Properties of Composite Coatings Obtained on Aluminium Alloys

    Directory of Open Access Journals (Sweden)

    Bara M.

    2016-09-01

    Full Text Available This paper presents methods of modifying the anode surface layers of Al2O3 by introducing carbon to their microstructure. Composite coatings were prepared using two different methods. In the first, coatings were formed by means of oxidation under constant current conditions. Anodic oxidation of aluminium was conducted in a multicomponent electrolyte with the addition of organic acids and graphite. The second method was based on the formation of oxide coatings in an electrolyte without the addition of graphite or heat treatment of the layers of succinic acid. The obtained coatings were tested using SEM, TEM, and GDOES (glow discharge optical emission spectrometry and their tribological and stereometric properties were measured. The study demonstrated the beneficial effects of the methods when used to improve the tribological properties of sliding couples.

  20. Laser alloying of aluminium to improve surface properties - MSSA 2010

    CSIR Research Space (South Africa)

    Mabhali, Luyolo AB

    2010-07-01

    Full Text Available and microstructure of the surface without affecting the bulk properties of the material. The process involves melting the substrate surface and injecting the powder of the alloying material into the melt pool. Process parameters such as laser power, beam spot size...

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

    International Nuclear Information System (INIS)

    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 elastoplastic model. (orig.)

  2. Continuous cooling transformation diagrams for 6XXX aluminium alloys

    International Nuclear Information System (INIS)

    Bryantsev, P Yu

    2009-01-01

    Continuous cooling transformation diagrams of aluminum solid solution decomposition in range of cooling rates 100-1900 deg. C/h were built for some alloys of Al-Mg-Si-Fe system. Influence of cooling rate and chemical composition on temperatures of start and finish of solution decomposition was determined.

  3. Experimental research on the ultimate strength of hard aluminium alloy 2017 subjected to short-time radioactive heating

    International Nuclear Information System (INIS)

    Dafang, Wu; Yuewu, Wang; Bing, Pan; Meng, Mu; Lin, Zhu

    2012-01-01

    Highlights: ► Ultimate strength at transient heating is critical to security design of missiles. ► We measure the ultimate strength of alloy 2017 subjected to transient heating. ► Experimental results at transient heating are lacking in strength design handbook. ► Ultimate strength of alloy 2017 experimented is much higher than handbook value. ► The results provide a new method for optimal design of high-speed flight vehicles. -- Abstract: Alloy 2017 (Al–Cu–Mg) is a hard aluminium alloy strengthened by heat treatment. Because of its higher strength, finer weldability and ductility, hard aluminium alloy 2017 has been widely used in the field of aeronautics and astronautics. However, the ultimate strength and other characteristic mechanical parameters of aluminium alloy 2017 in a transient heating environment are still unclear, as these key mechanical parameters are lacking in the existing strength design handbook. The experimental characterisation of these critical parameters of aluminium alloy 2017 is undoubtedly meaningful for reliably estimating life span of and improving safety in designing high-speed flight vehicles. In this paper, the high-temperature ultimate strength, loading time and other mechanical properties of hard aluminium alloy 2017 under different transient heating temperatures and loading conditions are investigated by combining a transient aerodynamic heating simulation system and a material testing machine. The experimental results reveal that the ultimate strength and loading capability of aluminium alloy 2017 subjected to transient thermal heating are much higher than those tested in a long-time stable high-temperature environment. The research of this work not only provides a substantial basis for the loading capability improvement and optimal design of aerospace materials and structures subject to transient heating but also presents a new research direction with a practical application value.

  4. Wear Characteristics of Hybrid Composites Based on Za27 Alloy Reinforced With Silicon Carbide and Graphite Particles

    Directory of Open Access Journals (Sweden)

    S. Mitrović

    2014-06-01

    Full Text Available The paper presents the wear characteristics of a hybrid composite based on zinc-aluminium ZA27 alloy, reinforced with silicon-carbide and graphite particles. The tested sample contains 5 vol.% of SiC and 3 vol.% Gr particles. Compocasting technique has been used to prepare the samples. The experiments were performed on a “block-on-disc” tribometer under conditions of dry sliding. The wear volumes of the alloy and the composite were determined by varying the normal loads and sliding speeds. The paper contains the procedure for preparation of sample composites and microstructure of the composite material and the base ZA27 alloy. The wear surface of the composite material was examined using the scanning electronic microscope (SEM and energy dispersive spectrometry (EDS. Conclusions were obtained based on the observed impact of the sliding speed, normal load and sliding distance on tribological behaviour of the observed composite.

  5. The Effect of Laser Surface Treatment on Structure and Mechanical Properties Aluminium Alloy ENAC-AlMg9

    Directory of Open Access Journals (Sweden)

    Pakieła W.

    2016-09-01

    Full Text Available In this work, the influence of a high power diode laser surface treatment on the structure and properties of aluminium alloy has been determined. The aim of this study was to improve the mechanical and tribological properties of the surface layer of the aluminium alloy by simultaneously melting and feeding tungsten carbide particles into the molten pool. During the process was used high-power diode laser HPDL. In order to remelt the aluminium alloy surface the HPDL laser of 1.8, 2.0 and 2.2 kW laser beam power has been used. The linear laser scan rate of the beam was set 0.5 cm/s. In order to protect the liquid metal during laser treatment was used argon. As a base material was used aluminium alloy ENAC-AlMg9. To improve the surface mechanical and wear properties of the applied aluminium alloy was used biphasic tungsten carbide WC/W2C. The size of alloying powder was in the range 110-210 µm. The ceramic powder was introduced in the remelting zone by a gravity feeder at a constant rate of 8 g/m.

  6. Experimental investigation of hardness of FSW and TIG joints of Aluminium alloys of AA7075 and AA6061

    Directory of Open Access Journals (Sweden)

    Chetan Patil

    2016-07-01

    Full Text Available This paper reports hardness testing conducted on welded butt joints by FSW and TIG welding process on similar and dissimilar aluminium alloys. FSW joints were produced for similar alloys of AA7075T651 and dissimilar alloys of AA7075T651- AA6061T6. The Friction stir welds of AA7075 & AA6061 aluminium alloy were produced at different tool rotational speeds of 650,700, 800, 900, 1000 and transverse speed of 30, 35, 40 mm/min. TIG welding was conducted along the rolling direction of similar and dissimilar aluminium plates. The Brinell hardness testing techniques were employed to conduct the tests; these tests were conducted on the welds to ascertain the joint integrity before characterization to have an idea of the quality of the welds

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Effect of Refiner Addition Level on Zirconium-Containing Aluminium Alloys

    International Nuclear Information System (INIS)

    Jaradeh, M M R; Carlberg, T

    2012-01-01

    It is well known that in aluminium alloys containing Zr, grain refiner additions do not function as desired, producing an effect often referred to as nuclei poisoning. This paper investigates the structure of direct chill-cast ingots of commercial AA3003 aluminium alloys, with and without Zr, at various addition levels of Al5Ti1B master alloy. In Bridgman experiments simulating ingot solidification, Zr-containing alloys were studied after the addition of various amounts of Ti. It could be demonstrated, in both ingot casting and simulation experiments, that Zr poisoning can be compensated for by adding more Ti and/or Al5Ti1B. The results confirm better refinement behaviour with the addition of Ti + B than of only Ti. The various combinations of Zr and Ti also influenced the formation of AlFeMn phases, and the precipitation of large Al 6 (Mn,Fe) particles was revealed. AlZrTiSi intermetallic compounds were also detected.

  9. Effect of Refiner Addition Level on Zirconium-Containing Aluminium Alloys

    Science.gov (United States)

    Jaradeh, M. M. R.; Carlberg, T.

    2012-01-01

    It is well known that in aluminium alloys containing Zr, grain refiner additions do not function as desired, producing an effect often referred to as nuclei poisoning. This paper investigates the structure of direct chill-cast ingots of commercial AA3003 aluminium alloys, with and without Zr, at various addition levels of Al5Ti1B master alloy. In Bridgman experiments simulating ingot solidification, Zr-containing alloys were studied after the addition of various amounts of Ti. It could be demonstrated, in both ingot casting and simulation experiments, that Zr poisoning can be compensated for by adding more Ti and/or Al5Ti1B. The results confirm better refinement behaviour with the addition of Ti + B than of only Ti. The various combinations of Zr and Ti also influenced the formation of AlFeMn phases, and the precipitation of large Al6(Mn,Fe) particles was revealed. AlZrTiSi intermetallic compounds were also detected.

  10. Development of continuous cooling precipitation diagrams for aluminium alloys AA7150 and AA7020

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y., E-mail: yong.zhang@outlook.com [ARC Centre of Excellence for Design in Light Metals, Department of Materials Engineering, Monash University, Clayton, VIC 3800 (Australia); Milkereit, B. [University of Rostock, Faculty of Mechanical Engineering and Marine Technology, Chair of Materials Science, 18051 Rostock (Germany); University of Rostock, Institute of Physics, Polymer Physics Group, 18051 Rostock (Germany); Kessler, O. [University of Rostock, Faculty of Mechanical Engineering and Marine Technology, Chair of Materials Science, 18051 Rostock (Germany); Schick, C. [University of Rostock, Institute of Physics, Polymer Physics Group, 18051 Rostock (Germany); Rometsch, P.A. [ARC Centre of Excellence for Design in Light Metals, Department of Materials Engineering, Monash University, Clayton, VIC 3800 (Australia)

    2014-01-25

    Highlights: • The DSC method was used for developing continuous cooling precipitation diagrams. • The quench-induced particles were observed by SEM for alloys AA7150 and AA7020. • There were more quench-induced particles in alloy AA7150. • Quench sensitivity of Al alloys can be evaluated by using the CCP diagrams. -- Abstract: Two commercial 7xxx series aluminium alloys with different solute contents and different quench-induced precipitation behaviour have been investigated by using a specialised differential scanning calorimetry (DSC) technique to record exothermal heat outputs during continuous cooling. Together with hardness testing and microstructural analysis, this DSC method was used to develop continuous cooling precipitation (CCP) diagrams for alloys AA7150 and AA7020. The results show that the total precipitation heat for each alloy decreases with increasing cooling rate. However, the excess specific heat at a given cooling rate in alloy AA7150 is much higher than that in alloy AA7020. It is evident that there are atleast three different quench-induced reactions in different temperature regimes for alloy AA7150 cooled at various linear cooling rates, but only equilibrium MgZn{sub 2} (η-phase) and Al{sub 2}CuMg (S-phase) particles were observed by scanning electron microscopy (SEM). There are at least two main precipitation peaks that can be found for alloy AA7020, which correspond to Mg{sub 2}Si and MgZn{sub 2} (η-phase). Furthermore, a method is developed to evaluate the quench sensitivity of an alloy based on a determination of the critical cooling rate. The maximum hardness values are reached at cooling rates that are faster than or similar to the critical cooling rate.

  11. The fatigue response of the aluminium-lithium alloy, 8090

    Science.gov (United States)

    Birt, M. J.; Beevers, C. J.

    1989-01-01

    The fatigue response of an Al-Li-Cu-Mg-Zr (8090) alloy has been studied at room temperature. The initiation and growth of small and long cracks has been examined at R = 0.1 and at a frequency of 100 Hz. Initiation was observed to occur dominantly at sub-grain boundaries. The growth of the small cracks was crystallographic in character and exhibited little evidence of retardation or arrest at the grain boundaries. The long crack data showed the alloy to have a high resistance to fatigue crack growth with underaging providing the optimum heat treatment for fatigue crack growth resistance. In general, this can be attributed to high levels of crack closure which resulted from the presence of extensive microstructurally related asperities.

  12. Microstructural characterization aluminium alloys from the addition of boron

    International Nuclear Information System (INIS)

    Nunes, A.G.P.; Pipano, T.F.; Mota, M.A.; Mariano, N.A.; Ramos, E.C.T.

    2014-01-01

    In the electrical industry, the aluminum becomes attractive because it has excellent characteristics for transmitting electricity. The liquid aluminum has in its composition transition elements (zirconium, titanium, vanadium and chromium) that interfere negatively on the quality of the product. The addition of aluminum-boron alloys have been used to remove transition metals through the formation of borides, enabling an increase in electrical conductivity. However, no detailed reports of reactions between boron, transition metals and primary aluminum engines. However, the objective is to determine the stoichiometric composition that enables an increase in electrical conductivity of an aluminum alloy. Samples with different concentrations of boron were characterized by optical emission spectrometry, electrical conductivity and X-ray diffraction. The addition of boron in excess reduces the time in the formation of borides, and enable an increase in electrical conductivity. (author)

  13. Effective hydrogen diffusion coefficient for solidifying aluminium alloys

    International Nuclear Information System (INIS)

    Felberbaum, M.; Landry-Desy, E.; Weber, L.; Rappaz, M.

    2011-01-01

    An effective hydrogen diffusion coefficient has been calculated for two solidifying Al - 4.5 wt.% Cu and Al - 10 wt.% Cu alloys as a function of the volume fraction of solid. For this purpose, in situ X-ray tomography was performed on these alloys. For each volume fraction of solid between 0.6 and 0.9, a representative volume element of the microstructure was extracted. Solid and liquid voxels were assimilated to solid and liquid nodes in order to solve the hydrogen diffusion equation based on the chemical potential and using a finite volume formulation. An effective hydrogen diffusion coefficient based on the volume fraction of solid only could be deduced from the results of the numerical model at steady state. The results are compared with various effective medium theories.

  14. Corrosion inhibition of 7000 series aluminium alloys with cerium diphenyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Julie-Anne [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Markley, Tracey [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); CSIRO, Division of Materials Science and Technology, Clayton, Victoria (Australia); Forsyth, Maria, E-mail: maria.forsyth@deakin.edu.au [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Howlett, Patrick C. [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Hinton, Bruce R.W. [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Defence Science and Technology Organisation, Melbourne, Victoria (Australia)

    2011-02-03

    Graphical abstract: Scanning electron micrographs of microtomed surface shows pristine surface free of corrosion related 'mud cracking' inset for an inhibited AA7050 specimen when only 150 ppm Ce(dpp)3 is present in 0.1 M NaCl solution. Display Omitted Research highlights: > The thin film of hydrolysis products of Ce(dpp)3 and aluminium oxide is proposed to cause the inhibition. > The film consists of discrete Ce rich particles and a thin film over the matrix of Ce, P and Al oxides. > Discrete deposition of Ce is specifically influenced by Cu rich intermetallics. - Abstract: Cerium diphenyl phosphate (Ce(dpp){sub 3}) has previously been shown to be a strong corrosion inhibitor for aluminium-copper magnesium alloy AA2024-T3 and AA7075 in chloride solutions. Surface characterisation including SEM and ToF-SIMS coupled with electrochemical impedance spectroscopy (EIS) measurements are used to propose a mechanism of corrosion inhibition which appears to involve the formation of a complex oxide film of aluminium and cerium also incorporating the organophosphate component. The formation of a thin complex film consisting of hydrolysis products of the Ce(dpp){sub 3} compound and aluminium oxide is proposed to lead to the observed inhibition. SEM analysis shows that some intermetallics favour the creation of thicker deposits predominantly containing cerium oxide compounds.

  15. The solidification behavior of dilute aluminium-scandium alloys

    International Nuclear Information System (INIS)

    Norman, A.F.; Prangnell, P.B.; McEwen, R.S.

    1998-01-01

    The solidification behavior of dilute Sc containing Al alloys has been investigated. In binary Al-Sc alloys, Sc additions greater than the eutectic composition (0.55 wt%) were found to produce a remarkable refinement in the grain size of aluminum castings, of two orders of magnitude, due to the formation of the primary Al 3 Sc intermetallic phase during solidification. The refinement in grain size only occurred in hypereutectic compositions and was shown to be far greater than can be achieved by conventional Al grain refiners. Grain refinement by the addition of Sc is accompanied by a change in growth morphology from dendritic, in the large unrefined grains, to fine spherical grains with a divorced eutectic appearing on the grain boundaries in the refined castings. Similar levels of refinement were observed in Al-Sc-Zr and Al-Cu-Sc alloys. In the latter, a change in the segregation behavior of Cu was observed, from a strongly interdendritic segregation pattern to a more homogeneous distribution. The supersaturated Al-Sc solid solution can decompose via a discontinuous precipitation reaction to form coherent rod-like precipitates of the L1 2 Al 3 Sc phase

  16. Producing a particle-reinforced AlCuMgMn alloy by means of mechanical alloying; Herstellung einer partikelverstaerkten AlCuMgMn-Legierung durch mechanisches Legieren

    Energy Technology Data Exchange (ETDEWEB)

    Nestler, D.; Wielage, B. [TU Chemnitz, Institut fuer Werkstoffwissenschaft und Werkstofftechnik (Germany); Siebeck, S.

    2012-07-15

    High-energy ball milling (HEM) with subsequent consolidation is a suitable method to produce particle-reinforced aluminium materials. The task of HEM is to distribute the reinforcement particles as homogeneously as possible. A further application of HEM is mechanical alloying (MA). This paper deals with the combination of both applications. Pure metallic powders (Al, Cu, Mg, Mn) were milled together with SiC particles up to 10 h. The composition of the metallic powder corresponds to that of the alloy AA2017 (3.9% Cu, 0.7% Mg, 0.6% Mn). In previous experiments [1], this alloy was used in the form of atomized powder. The changes in microstructure during the formation of the composite powder have been studied by light microscopy, SEM, EDXS and XRD. The results show that the production of composite powders in a single step is possible. This not only allows the economical production of such powders, but also facilitates the use of alloy compositions that are not producible via the melting route, or only producible with difficulty via the melting route. It's possible to produce tailor-made-alloys. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Effect of pulsed current welding on fatigue behaviour of high strength aluminium alloy joints

    International Nuclear Information System (INIS)

    Balasubramanian, V.; Ravisankar, V.; Madhusudhan Reddy, G.

    2008-01-01

    High strength aluminium alloys (Al-Zn-Mg-Cu alloys) have gathered wide acceptance in the fabrication of light weight structures requiring high strength-to weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. The preferred welding processes of high strength aluminium alloy are frequently gas tungsten arc welding (GTAW) process and gas metal arc welding (GMAW) process due to their comparatively easier applicability and better economy. Weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal solidification. This often results inferior weld mechanical properties and poor resistance to hot cracking. In this investigation, an attempt has been made to refine the fusion zone grains by applying pulsed current welding technique. Rolled plates of 6 mm thickness have been used as the base material for preparing single pass welded joints. Single V butt joint configuration has been prepared for joining the plates. The filler metal used for joining the plates is AA 5356 (Al-5Mg (wt%)) grade aluminium alloy. Four different welding techniques have been used to fabricate the joints and they are: (i) continuous current GTAW (CCGTAW), (ii) pulsed current GTAW (PCGTAW), (iii) continuous current GMAW (CCGMAW) and (iv) pulsed current GMAW (PCGMAW) processes. Argon (99.99% pure) has been used as the shielding gas. Fatigue properties of the welded joints have been evaluated by conducting fatigue test using rotary bending fatigue testing machine. Current pulsing leads to relatively finer and more equi-axed grain structure in gas tungsten arc (GTA) and gas metal arc (GMA) welds. In contrast, conventional continuous current welding resulted in predominantly columnar grain structures. Grain refinement is accompanied by an increase in fatigue life and endurance limit

  18. Tensile behavior of dissimilar friction stir welded joints of aluminium alloys

    International Nuclear Information System (INIS)

    Shanmuga Sundaram, N.; Murugan, N.

    2010-01-01

    The heat treatable aluminium alloy AA2024 is used extensively in the aircraft industry because of its high strength to weight ratio and good ductility. The non-heat treatable aluminium alloy AA5083 possesses medium strength and high ductility and used typically in structural applications, marine, and automotive industries. When compared to fusion welding processes, friction stir welding (FSW) process is an emerging solid state joining process which is best suitable for joining these alloys. The friction stir welding parameters such as tool pin profile, tool rotational speed, welding speed, and tool axial force influence the mechanical properties of the FS welded joints significantly. Dissimilar FS welded joints are fabricated using five different tool pin profiles. Central composite design with four parameters, five levels, and 31 runs is used to conduct the experiments and response surface method (RSM) is employed to develop the model. Mathematical regression models are developed to predict the ultimate tensile strength (UTS) and tensile elongation (TE) of the dissimilar friction stir welded joints of aluminium alloys 2024-T6 and 5083-H321, and they are validated. The effects of the above process parameters and tool pin profile on tensile strength and tensile elongation of dissimilar friction stir welded joints are analysed in detail. Joints fabricated using Tapered Hexagon tool pin profile have the highest tensile strength and tensile elongation, whereas the Straight Cylinder tool pin profile have the lowest tensile strength and tensile elongation. The results are useful to have a better understanding of the effects of process parameters, to fabricate the joints with desired tensile properties, and to automate the FS welding process.

  19. Investigation on Mechanical and Fatigue behaviour of Aluminium Based SiC/ZrO2 Particle Reinforced MMC

    Science.gov (United States)

    Ramesh, S.; Govindaraju, N.; Suryanarayan, C. P.

    2018-04-01

    The study is the work on Aluminium Metal Matrix Composites (MMC’s), which have wider applications in automobile, aerospace and defense industries, hi-tech engineering and power transmission due to their lightweight, high strength and other unique properties. The Aluminium Matrix Composites (AMC’s) refer to a kind of light weight high performance Aluminium centric material system. AMC’s consist of a non-metallic reinforcement which when included into aluminium matrix offers an advantage over the base material. Reinforcements like SiC, B4C, Al2O3, TiC, TiB2, TiO2 are normally preferred to improve mechanical properties of such composites. Here Aluminium 6061 is preferred as matrix material, while silicon carbide (SiC) and Zirconium di-oxide (ZrO2) is selected as reinforcement compounds. Conventional Stir casting procedure is employed to fabricate the necessary composites compositions, which are I. Al:SiC::100:5 and II. Al:ZrO2:SiC::100:3:2. Experimental results depict that the composition II provides higher hardness of 53.6 RHN as opposed to 45.8 RHN of composition I. In tensile strength composition II demonstrates 96.43 N/mm2 as opposed to 67.229 N/mm2 tensile strength of composition II. The fatigue test indicate a expected number of life cycles to failure of 105 cycles for composition II and over 104 cycles for composition I, at stress ranges of 79.062 MPa and 150.651 MPa respectively.

  20. 3D study of intermetallics and their effect on the corrosion morphology of rheocast aluminium alloy

    International Nuclear Information System (INIS)

    Mingo, B.; Arrabal, R.; Pardo, A.; Matykina, E.; Skeldon, P.

    2016-01-01

    In the present study, the effect of heat treatment T6.1 on the microstructure and corrosion behaviour of rheocast aluminium alloy A356 is investigated on the basis of 2D/3D characterization techniques and electrochemical and SKPFM measurements. Heat treatment strengthens the α-Al matrix, modifies the intermetallic particles and spheroidizes eutectic Si. These changes do not modify significantly the corrosion behaviour of the alloy. 3D SEM-Tomography clearly shows that the corrosion advances in the shape of narrow paths between closely spaced intermetallics without a major influence of eutectic Si. - Highlights: • T6.1 spheroidizes Si, strengthens the matrix and modifies the intermetallics. • Electrochemical behaviour of untreated and heat-treated alloys is similar. • 3D SEM-Tomography provides additional information on the corrosion morphology. • Corrosion advances as paths between intermetallics with little influence of Si.

  1. Effect of process parameters on tensile strength of friction stir welding A356/C355 aluminium alloys joint

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, Shashi Prakash [Noida Institute of Engineering and Technology, Greater Noida (Korea, Republic of)

    2014-01-15

    In the present investigation, A356/C355 aluminium alloys are welded by friction stir welding by controlling various welding parameters. A356 and C355 aluminium alloys materials have a set of mechanical and physical properties that are ideally suited for application in aerospace and automobile industries and not widely used because of its poor weldebility. To overcome this barrier, weldebility analysis of A356 and C355 aluminium alloys with high speed steel (Wc-Co) tool has been investigated. An attempt has been made to investigate the influence of the rotational speed of the tools, the axial force and welding speed on tensile strength of A356/C355 aluminium alloys joint. The experiments were conducted on a milling machine. The main focus of investigation is to determine good tensile strength. Response surface methodology (box Behnken design) is chosen to design the optimum welding parameters leading to maximum tensile strength. The result shows that axial force increases, tensile strength decreases. Whereas tool rotational speed and welding speed increase, tensile strength increases. Optimum values of axial force (3 /KN), tool rotational speed (900 RPM) and welding speed (75 mm/min.) during welding of A356/C355 aluminium alloys joint to maximize the tensile strength (Predicted 223.2 MPa) have been find out.

  2. Effect of process parameters on tensile strength of friction stir welding A356/C355 aluminium alloys joint

    International Nuclear Information System (INIS)

    Dwivedi, Shashi Prakash

    2014-01-01

    In the present investigation, A356/C355 aluminium alloys are welded by friction stir welding by controlling various welding parameters. A356 and C355 aluminium alloys materials have a set of mechanical and physical properties that are ideally suited for application in aerospace and automobile industries and not widely used because of its poor weldebility. To overcome this barrier, weldebility analysis of A356 and C355 aluminium alloys with high speed steel (Wc-Co) tool has been investigated. An attempt has been made to investigate the influence of the rotational speed of the tools, the axial force and welding speed on tensile strength of A356/C355 aluminium alloys joint. The experiments were conducted on a milling machine. The main focus of investigation is to determine good tensile strength. Response surface methodology (box Behnken design) is chosen to design the optimum welding parameters leading to maximum tensile strength. The result shows that axial force increases, tensile strength decreases. Whereas tool rotational speed and welding speed increase, tensile strength increases. Optimum values of axial force (3 /KN), tool rotational speed (900 RPM) and welding speed (75 mm/min.) during welding of A356/C355 aluminium alloys joint to maximize the tensile strength (Predicted 223.2 MPa) have been find out.

  3. Properties of experimental copper-aluminium-nickel alloys for dental post-and-core applications.

    Science.gov (United States)

    Rittapai, Apiwat; Urapepon, Somchai; Kajornchaiyakul, Julathep; Harniratisai, Choltacha

    2014-06-01

    This study aimed to develop a copper-aluminium-nickel alloy which has properties comparable to that of dental alloys used for dental post and core applications with the reasonable cost. Sixteen groups of experimental copper alloys with variants of 3, 6, 9, 12 wt% Al and 0, 2, 4, 6 wt% Ni were prepared and casted. Their properties were tested and evaluated. The data of thermal, physical, and mechanical properties were analyzed using the two-way ANOVA and Tukey's test (α=0.05). The alloy toxicity was evaluated according to the ISO standard. The solidus and liquidus points of experimental alloys ranged from 1023℃ to 1113℃ and increased as the nickel content increased. The highest ultimate tensile strength (595.9 ± 14.2 MPa) was shown in the Cu-12Al-4Ni alloy. The tensile strength was increased as the both elements increased. Alloys with 3-6 wt% Al exhibited a small amount of 0.2% proof strength. Accordingly, the Cu-9Al-2Ni and Cu-9Al-4Ni alloys not only demonstrated an appropriate modulus of elasticity (113.9 ± 8.0 and 122.8 ± 11.3 GPa, respectively), but also had a value of 0.2% proof strength (190.8 ± 4.8 and 198.2 ± 3.4 MPa, respectively), which complied with the ISO standard requirement (>180 MPa). Alloys with the highest contents of nickel (6 wt% Ni) revealed a widespread decolourisation zone (5.0-5.9 mm), which correspondingly produced the largest cell response, equating positive control. The copper alloys fused with 9 wt% Al and 2-4 wt% Ni can be considered for a potential use as dental post and core applications.

  4. Influence of heat treatment on fatigue performances for self-piercing riveting similar and dissimilar titanium, aluminium and copper alloys

    OpenAIRE

    Zhang, Xianlian; He, Xiaocong; Xing, Baoying; Zhao, Lun; Lu, Yi; Gu, Fengshou; Ball, Andrew

    2016-01-01

    The fatigue performances of self-piercing riveting (SPR) joints connecting similar and dissimilar sheets of TA1 titanium alloy (TA1), Al5052 aluminium alloy (Al5052) and H62 copper alloy (H62) were studied in this paper. The specimens of similar TA1 sheets treated with stress relief annealing were prepared to investigate the influence of relief annealing on the mechanical properties of SPR joints. Fatigue tests were conducted to characterize the fatigue lives and failure modes of the joints. ...

  5. Wear Resistance Increase by Friction Stir Processing for Partial Magnesium Replacement in Aluminium Alloys

    Science.gov (United States)

    Balos, Sebastian; Labus Zlatanovic, Danka; Janjatovic, Petar; Dramicanin, Miroslav; Rajnovic, Dragan; Sidjanin, Leposava

    2018-03-01

    In this paper, the influence of friction stir processing (FSP) was evaluated as a way of increasing mechanical properties and a way of replacing the magnesium content in aluminium alloys. FSP was done on AA5754 H111 aluminium alloy, containing 3 % Mg, by using various types of tools and different welding speeds, rotational speeds and tilt angles. Wear test was done against SiC abrasive papers. SiC was used to simulate extreme abrasive wear conditions. The wear test was done on untreated AA5754 specimens, processed AA5754 specimens and untreated AA5083 H111 specimens, the latter containing 4.5 % Mg. AA5083 was chosen as an alternative to AA5754, but with a significantly higher Mg content. Base material microhardness was 60 HV1 and 80 HV1 for AA5754 and AA5083 alloys respectively. To find the effect of FSP on AA5754 alloy, microstructures were studied, mainly grain size in the stir zone. It was found, that an elevated processing and rotational speed, without tilt angle and the tool without a reservoir resulted in an increase in hardness of the AA5754 to 70 HV1, but with the occurrence of tunneling defect and the wear rate of 79.3 mg. Lower FSP parameters and a tilted tool with a reservoir resulted in microhardness of 68 HV1 and wear rate of 68.2 mg without tunneling. These wear values are lower than those obtained with unmodified Al-alloys: AA5754 97.2 mg and AA5083 86.3 mg. An increased wear resistance can be attributed to the combined effect of grain boundary strengthening mechanism and solid solution strengthening, versus only the latter in untreated alloys.

  6. Determination of lattice orientation in aluminium alloy grains by low energy gallium ion-channelling

    Energy Technology Data Exchange (ETDEWEB)

    Silk, Jonathan R. [Aerospace Metal Composites Ltd., RAE Road, Farnborough, GU14 6XE (United Kingdom); Dashwood, Richard J. [WMG, University of Warwick, Coventry, CV4 7AL (United Kingdom); Chater, Richard J., E-mail: r.chater@imperial.ac.u [Department of Materials, Imperial College, London SW7 2AZ (United Kingdom)

    2010-06-15

    Polished sections of a fine-grained aluminium, silicon carbide metal matrix composite (MMC) alloy were prepared by sputtering using a low energy gallium ion source and column (FIB). The MMC had been processed by high temperature extrusion. Images of the polished surface were recorded using the ion-induced secondary electron emission. The metal matrix grains were distinguished by gallium ion-channelling contrast from the silicon carbide component. The variation of the contrast from the aluminium grains with tilt angle can be recorded and used to determine lattice orientation with the contrast from the silicon carbide (SiC) component as a reference. This method is rapid and suits site-specific investigations where classical methods of sample preparation fail.

  7. Microstructure and wear behaviour of aluminium alloys containing embedded nanoscaled lead dispersoids

    International Nuclear Information System (INIS)

    Bhattacharya, Victoria; Chattopadhyay, K.

    2004-01-01

    We report the early stage friction and wear characteristics of aluminium containing nanosized lead dispersions. The nanocomposite was produced by rapid solidification. The experimental results indicate a significant decrease in friction and wear rate in comparison to its coarse grained counterparts. We show that the observed results suggest an adhesive type of wear mechanism. However, increase in hardness due to refinement of the aluminium grains cannot quantitatively rationalize the results. We explore and discuss the role of nanoscaled lead particles and the mass transport between the sample and counterface via mechanical alloying, in the formation of tribolayers affecting the tribological properties. The plane view and cross-sectional transmission electron microscopy reveals significant elongation as well as coarsening of the lead particles during the process of wear. We attempt to understand these results in the framework of moving dislocations and their assistance to the mass transport among the dispersed lead particles

  8. Finite Element Analysis of Warpage in Laminated Aluminium Alloy Plates for Machining of Primary Aeronautic Parts

    International Nuclear Information System (INIS)

    Reis, A. C.; Moreira Filho, L. A.; Menezes, M. A.

    2007-01-01

    The aim of this paper consists in presenting a method of simulating the warpage in 7xxx series aluminium alloy plates. To perform this simulation finite element software MSC.Patran and MSC.Marc were used. Another result of this analysis will be the influence on material residual stresses induced on the raw material during the rolling process upon the warpage of primary aeronautic parts, fabricated through machining (milling) at Embraer. The method used to determinate the aluminium plate residual stress was Layer Removal Test. The numerical algorithm Modified Flavenot Method was used to convert layer removal and beam deflection in stress level. With such information about the level and profile of residual stresses become possible, during the step that anticipate the manufacturing to incorporate these values in the finite-element approach for modelling warpage parts. Based on that warpage parameter surely the products are manufactured with low relative vulnerability propitiating competitiveness and price

  9. Microstructural characteristics, mechanical and wear behaviour of aluminium matrix hybrid composites reinforced with alumina, rice husk ash and graphite

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo Alaneme

    2015-09-01

    Full Text Available The microstructural characteristics, mechanical and wear behaviour of Aluminium matrix hybrid composites reinforced with alumina, rice husk ash (RHA and graphite were investigated. Alumina, RHA and graphite mixed in varied weight ratios were utilized to prepare 10 wt% hybrid reinforced Al-Mg-Si alloy based composites using two-step stir casting. Hardness, tensile properties, scanning electron microscopy, and wear tests were used to characterize the composites produced. The results show that Hardness decreases with increase in the weight ratio of RHA and graphite in the composites; and with RHA content greater than 50%, the effect of graphite on the hardness becomes less significant. The tensile strength for the composites containing o.5wt% graphite and up to 50% RHA was observed to be higher than that of the composites without graphite. The toughness values for the composites containing 0.5wt% graphite were in all cases higher than that of the composites without graphite. The % Elongation for all composites produced was within the range of 10–13% and the values were invariant to the RHA and graphite content. The tensile fracture surface morphology in all the composites produced was identical characterized with the presence of reinforcing particles housed in ductile dimples. The composites without graphite exhibited greater wear susceptibility in comparison to the composite grades containing graphite. However the wear resistance decreased with increase in the graphite content from 0.5 to 1.5 wt%.

  10. Effect of type and percentage of reinforcement for optimization of the cutting force in turning of Aluminium matrix nanocomposites using response surface methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Priyadarshi, Devinder [DAV Institute of Engineering and Technology, Jalandhar (India); Sharma, Rajesh Kumar [Institute of Technology, Hamirpur (India)

    2016-03-15

    Aluminium matrix composites (AMCs) now hold a significant share of raw materials in many applications. It is of prime importance to study the machinability of such composites so as to enhance their applicability. Sufficient work has been done for studying the machining of AMCs with particle reinforcements of micron range. This paper presents the study of AMCs with particle reinforcement of under micron range i.e. nanoparticles. This paper brings out the results of an experimental investigation of type and weight percent of nanoparticles on the tangential cutting force during turning operation. SiC, Gr and SiC-Gr (in equal proportions) were used with Al-6061 alloy as the matrix phase. The results indicate that composites with SiC require greater cutting force followed by hybrid and then Gr. Increase in the weight percent also significantly affected the magnitude of cutting force. RSM was used first to design and analyze the experiments and then to optimize the turning process and obtain optimal conditions of weight and type of reinforcements for turning operation.

  11. Aluminum alloy production for the reinforcement of the CMS conductor

    CERN Document Server

    Sequeira-Lopes-Tavares, S; Campi, D; Curé, B; Horváth, I L; Riboni, P; Sgobba, Stefano; Smith, R P

    2002-01-01

    The Compact Muon Solenoid (CMS) is one of the general-purpose detectors to be provided for the Large Hadron Collider (LHC) project at CERN. The design field of the CMS superconducting magnet is 4 T, the magnetic length is 12.5 m and the free bore is 6 m. To reinforce the high-purity (99.998%) Al-stabilized conductor of the magnet against the magnetic loadings experienced during operation at 4.2 K, two continuous sections of Al-alloy (AA) reinforcement are Electron Beam (EB) welded to it. The reinforcements have a section of 24*18 mm and are produced in continuous 2.55 km lengths. The alloy EN AW-6082 has been selected for the reinforcement due to its excellent extrudability, high strength in the precipitation hardened states, high toughness and strength at cryogenic temperature and good EB weldability. Each of the continuous lengths of the reinforcement is extruded billet on billet and press quenched on-line from the extrusion temperature in an industrial extrusion plant. In order to insure the ready EB welda...

  12. Corrosion Characteristics and Kinetics of Zircaloys and Aluminium Alloys

    International Nuclear Information System (INIS)

    Sugondo; Chaidir, A

    1998-01-01

    Corrosion rate characterization of cladding materials has been done by dynamic method. The materials are zircaloy-2,zircaloy-4,AIMg2,and AIMgSi.The zircaloy alloys are characterized in the electrolytes of boric ion,iodide ion,lithium ion and cesium ion with a pH variation.The aluminum alloys are characterized in the cooling water of RSG-GAS reactor in different temperatures and Ph values .The results, show that corrosion product of iodine on zircaloy is not passivated, meanwhile the corrosion product of cesium undergoes passivation. However, the deposited substance in the surface of the specimens as indicated using WDX-SEM shows the same deposition rate.it is concluded therefore that iodine is diffused into the materials without getting resistance from the deposited substances on the surface. The effect of pH to corrosion rate of iodine on the zircaloy fluctuates meanwhile the cesium has the minimum corrosion rate at pH 7.5 At the concentration of 0.1 gram/1,cesium ion is more reactive than iodine but at higher concentration the reactivity becomes competitive . Furthermore , the interaction between zircaloy and boric ion at concentration of 300 ppm and lithium ion at 10 ppm shows an outstanding corrosion rate, i.e. 0.1 mpy. if both substances are mixed then the corrosion rate decreases drastically in the order of 10 -2 mpy.The reason of such a decrease may be due to the formation of complexes of boron lithium on the electrode surface. The arrhenius activation energies for such reaction have been found to be 37629.322 joule/mole 0 K for Al Mg 2 and 41609.822 joule /mole 0 K for AIMgSi ,respectively. This underlies the argument that AI Mg 2 is more reactive than AI Mg Si besides , AI Mg 2 is more reactive under acid condition meanwhile AI Mg Si more reactive under basic condition. Both alloys over come the minimum corrosion rate at the pH in between 4.7 to 7.5 and the level of the corrosion rate in the pH interval was outstanding

  13. Microstructure and age-hardening effects of aluminium alloys with additions of scandium and zirconium

    Energy Technology Data Exchange (ETDEWEB)

    Galun, R.; Mordike, B.L. [Inst. fuer Werkstoffkunde und Werkstofftechnik, Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany); Maiwald, T.; Smola, B. [Zentrum fuer Funktionswerkstoffe GmbH, Clausthal-Zellerfeld (Germany); Mergen, R.; Manner, M.; Uitz, W. [Miba Gleitlager GmbH, Laakirchen (Australia)

    2004-12-01

    The aim of the work presented in this report was to produce age-hardenable aluminium alloys containing scandium and zirconium by a casting process with similar cooling conditions like an industrial casting process. Microstructure, precipitation structure and age-hardening response of different alloys with up to 0.4 wt.% Sc and Zr were investigated. Age-hardening experiments from the as-cast condition without solution annealing showed a significant increase of hardness of about 100% for Sc-rich alloys and of 50% for Zr-rich alloys compared to the as-cast condition. TEM investigations revealed the formation of precipitates of ternary Al{sub 3}(Sc{sub x}Zr{sub 1-x}) phases with a cubic cP4 crystal structure. In addition to the strengthening effect, a high thermal stability especially of the precipitates in Zr-rich alloys up to 400 C let these alloys look very promising for high-temperature applications. (orig.)

  14. The microstructure of mechanically alloyed nanocrystalline aluminium-magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Gubicza, J. [Dept. of General Physics, Eoetvoes Univ., Budapest (Hungary); Dept. of Solid State Physics, Eoetvoes Univ., Budapest (Hungary); Kassem, M. [Dept. of Materials Science and Engineering, Faculty of Petroleum and Mining, Suez Canal Univ., Suez (Egypt); Ungar, T. [Dept. of General Physics, Eoetvoes Univ., Budapest (Hungary)

    2004-07-01

    The effect of the nominal Mg content and the milling time on the microstructure of mechanically alloyed Al(Mg) solid solutions is studied. The crystallite size distribution and the dislocation structure are determined by X-ray diffraction peak profile analysis. Magnesium gradually goes into solid solution during ball milling and after 3 h almost all of the Mg atoms are soluted into the Al matrix. With increasing milling time the Mg content in solid solution, the dislocation density as well as the hardness are increasing, whereas the crystallite size is decreasing. A similar tendency of these parameters is observed at a particular duration of ball milling with increasing of the nominal Mg content. At the same time for a long milling period the dislocation density slightly decreases together with a slight reduction of the hardness. (orig.)

  15. Microstructural features of friction stir welded dissimilar Aluminium alloys AA2219-AA7475

    Science.gov (United States)

    Zaman Khan, Noor; Ubaid, Mohammed; Siddiquee, Arshad Noor; Khan, Zahid A.; Al-Ahmari, Abdulrahman; Chen, Xizhang; Haider Abidi, Mustufa

    2018-05-01

    High strength, good corrosion resistance, light weight make aluminium alloys a material of choice in many industrial sectors like aerospace, marine etc. Problems associated with welding of these alloys by fusion welding processes restricted their use in various industries. Friction stir welding (FSW), a clean solid-state joining process, easily overcomes various difficulties encountered during conventional fusion welding processes. In the present work, the effect of rotational speed (710 rpm, 900 rpm and 1120 rpm) on micro-hardness distribution and microstructure of FSWed dissimilar aluminium alloy joints were analyzed. Plates of AA7475-T761 and AA2219-O having thickness of 2.5 mm were welded by fixing AA7475 on retreating side (RS) and AA2219 on advancing side (AS). Welded joints were characterized by Vickers micro-hardness testing, scanning electron microscopy (SEM) and optical microscopy (OM). Results revealed that rotational speed significantly affects the micro-hardness due to increase in grain size, coarsening and dissolution of strengthening precipitates and re-precipitation. Higher micro-hardness values were observed in stir zone due to grain refinement and re-precipitation. Minimum micro-hardness value was observed at the TMAZ/HAZ of advancing side due to thermal softening.

  16. Experimental and theoretical investigation on corrosion inhibition of AA5052 aluminium alloy by L-cysteine in alkaline solution

    International Nuclear Information System (INIS)

    Wang, Dapeng; Gao, Lixin; Zhang, Daquan; Yang, Dong; Wang, Hongxia; Lin, Tong

    2016-01-01

    The corrosion inhibition of L-cysteine on AA5052 aluminium alloy in 4 mol/L NaOH solution was investigated by hydrogen gas evolution experiment, polarisation curve, galvanostatic discharge, electrochemical impedance spectroscopy measurements and quantum chemical calculations. The adsorption of L-cysteine on aluminium alloy surface obeyed the amended Langmuir's adsorption isotherm. The polarisation curves indicated that L-cysteine acted as a cathodic inhibitor to inhibit cathodic reaction. The inhibition mechanism was dominated by the geometric covering effect. The galvanostatic discharge shows that the additives restrain the hydrogen evolution and increase the anodic utilization rate. Quantum chemical calculations indicated that L-cysteine molecules mainly interacted with on the carboxyl groups on the aluminium alloy surface. A strong hybridization occurred between the s-orbital and p-orbital of reactive sites in the L-cysteine molecule and the sp-orbital of Aluminium. - Highlights: • L-cysteine was used as corrosion inhibitor for Al alloy in alkaline solution. • Adsorption of L-cysteine on Al alloy surface obeyed the amended Langmuir's isotherm. • L-cysteine molecules interacted with the carboxyl groups on the Al alloy surface. • A strong orbital hybridization occurred between the reactive sites in L-cysteine and Al.

  17. Experimental and theoretical investigation on corrosion inhibition of AA5052 aluminium alloy by L-cysteine in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dapeng; Gao, Lixin [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Zhang, Daquan, E-mail: zhangdaquan@shiep.edu.cn [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Yang, Dong [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Hongxia; Lin, Tong [Institute for Frontier Materials, Deakin University, Geelong, VIC 3216 (Australia)

    2016-02-01

    The corrosion inhibition of L-cysteine on AA5052 aluminium alloy in 4 mol/L NaOH solution was investigated by hydrogen gas evolution experiment, polarisation curve, galvanostatic discharge, electrochemical impedance spectroscopy measurements and quantum chemical calculations. The adsorption of L-cysteine on aluminium alloy surface obeyed the amended Langmuir's adsorption isotherm. The polarisation curves indicated that L-cysteine acted as a cathodic inhibitor to inhibit cathodic reaction. The inhibition mechanism was dominated by the geometric covering effect. The galvanostatic discharge shows that the additives restrain the hydrogen evolution and increase the anodic utilization rate. Quantum chemical calculations indicated that L-cysteine molecules mainly interacted with on the carboxyl groups on the aluminium alloy surface. A strong hybridization occurred between the s-orbital and p-orbital of reactive sites in the L-cysteine molecule and the sp-orbital of Aluminium. - Highlights: • L-cysteine was used as corrosion inhibitor for Al alloy in alkaline solution. • Adsorption of L-cysteine on Al alloy surface obeyed the amended Langmuir's isotherm. • L-cysteine molecules interacted with the carboxyl groups on the Al alloy surface. • A strong orbital hybridization occurred between the reactive sites in L-cysteine and Al.

  18. Residual Stress Measurement of Coarse Crystal Grain in Aluminium Casting Alloy by Neutron Diffraction

    International Nuclear Information System (INIS)

    Nishida, Masayuki; Watanabe, Yoshitaka; Hanabusa, Takao

    2009-01-01

    Full text: Neutron stress measurement can detect strain and stress information in deep region because of large penetration ability of neutron beams. The present paper describes procedure and results in the residual stress measurement of aluminium casting alloy by neutron diffraction. Usually, the aluminium casting alloy includes the large crystal grains. The existence of large crystal grains makes it difficult to estimate the residual stresses in highly accuracy. In this study, the modified three axial method using Hook's equation was employed for neutron stress measurement. These stress measurements were performed under the two kinds of new techniques. One is a rocking curve method to calculate the principal strains in three directions. The peak profiles which appear discretely on rocking curves were translated to principle stresses by the Bragg law and the basic elastic theory. Another is the consideration of measurement positions and the edge effect in the neutron irradiated area (volume gage). The edge effect generates the errors of 2θ-peak position in the neutron stress measurement. In this study, the edge effect was investigated in detail by a small bit of copper single crystal. The copper bit was moved and scanned on three dimensionally within the gage volume. Furthermore, the average strains of symmetrical positions are measure by the sample turning at 180 degrees, because the error distributions of the 2θ-peak position followed to positions inside the gage volume. Form these results of this study, the residual stresses in aluminium casting alloy which includes the large crystal grains were possible to estimate by neutron stress measurement with the rocking curve method and the correction of the edge effect. (author)

  19. Evaluation of HEBM Mechanical Alloying of Al2O3— 356/7075 Powder Mixture

    CSIR Research Space (South Africa)

    Govender, G

    2012-04-01

    Full Text Available Particle reinforced aluminium alloy metal matrix composites (MMC) have proven to be one of the advanced materials capable of replacing conventional structural alloys. However, the demand for such materials has been confined to high cost applications...

  20. Magnesium alloy AZ63A reinforcement by alloying with gallium and using high-disperse ZrO2 particles

    Directory of Open Access Journals (Sweden)

    J. Khokhlova

    2016-12-01

    Full Text Available The aim of this work was to obtain an experimental magnesium alloy by remelting standard AZ63A alloy with addition of gallium ligatures and ZrO2 particles. This allowed reinforcement of alloy and increase its hardness and Young's modulus. The chemical analysis of this alloy shows two types of structures which are evenly distributed in volume. Thus we can conclude that reinforcing effect is the result of formation of intermetallic phase Mg5-Ga2.

  1. Laser shock peening on a 6056-T4 aluminium alloy for airframe applications

    CSIR Research Space (South Africa)

    Glaser, D

    2014-03-01

    Full Text Available stream_source_info Pityana1_2014_ABSTRACT ONLY.pdf.txt stream_content_type text/plain stream_size 1356 Content-Encoding ISO-8859-1 stream_name Pityana1_2014_ABSTRACT ONLY.pdf.txt Content-Type text/plain; charset=ISO-8859-1... Laser Shock Peening on a 6056-T4 Aluminium Alloy for Airframe Applications Daniel Glaser, Claudia Polese, Rachana D. Bedekar, Jasper Plaisier,Sisa Pityana, Bathusile Masina, Tebogo Mathebula, and Enrico Troiani Keywords: Laser Shock Peening...

  2. MODELLING STUDIES ON THE USE OF ALUMINIUM ALLOYS IN LIGHTWEIGHT LOAD-CARRYING CRANE STRUCTURES

    Directory of Open Access Journals (Sweden)

    Damian GĄSKA

    2016-09-01

    Full Text Available The article presents the results of numerical analysis whose aim was to compare the basic dynamic and strength parameters of lightweight load-carrying crane structures made of aluminium alloys and steel. The analysis covered the typical construction of workshop cranes with a span of 3 to 5 meters, girders in the form of an I-beam and maximum load capacities amounting to 5 tons. The values of stresses, deflections and natural frequencies were compared and then matched with the masses of the various structures. In the simulation a girder model was used and computed by the finite element method.

  3. The role of silicon in the corrosion of AA6061 aluminium alloy laser weldments

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, A.B.M. Mujibur; Kumar, Sunil [Ian Wark Research Institute, University of South Australia, Mawson Lakes Campus, Mawson Lakes, SA 5095 (Australia); Gerson, Andrea R. [Applied Centre for Structural and Synchrotron Studies, University of South Australia, Mawson Lakes Campus, Mawson Lakes, SA 5095 (Australia)], E-mail: Andrea.Gerson@unisa.edu.au

    2010-06-15

    The galvanic corrosion temporal increase observed on examination of the weld fusion zone (WFZ) of AA6061 laser weldments in 3.5 wt.% NaCl solution cannot be attributed to electron tunnelling as the surface oxide layer is too thick, or the presence of Cl{sup -} within the surface layer as this element was not found to be present. Aluminium alloy and WFZ galvanic and surface analyses indicate that the cathodic WFZ corrosion characteristics are due to increases in silicate concentrations in the surface oxide layer, leading to increased ionic and/or p-type semi-conductor conductivity, intermetallic concentrations and surface area.

  4. The role of silicon in the corrosion of AA6061 aluminium alloy laser weldments

    International Nuclear Information System (INIS)

    Rahman, A.B.M. Mujibur; Kumar, Sunil; Gerson, Andrea R.

    2010-01-01

    The galvanic corrosion temporal increase observed on examination of the weld fusion zone (WFZ) of AA6061 laser weldments in 3.5 wt.% NaCl solution cannot be attributed to electron tunnelling as the surface oxide layer is too thick, or the presence of Cl - within the surface layer as this element was not found to be present. Aluminium alloy and WFZ galvanic and surface analyses indicate that the cathodic WFZ corrosion characteristics are due to increases in silicate concentrations in the surface oxide layer, leading to increased ionic and/or p-type semi-conductor conductivity, intermetallic concentrations and surface area.

  5. A comparative study of leaves extracts for corrosion inhibition effect on aluminium alloy in alkaline medium

    Directory of Open Access Journals (Sweden)

    Namrata Chaubey

    2017-12-01

    Full Text Available This paper deals with the comparative inhibition study of some plants leaves extract namely Cannabis sativa (CS, Rauwolfia serpentina (RS, Cymbopogon citratus (CC, Annona squamosa (AS and Adhatoda vasica (AV on the corrosion of aluminium alloy (AA in 1 M NaOH. The corrosion tests were performance by using gravimetric, electrochemical impedance spectroscopy (EIS, potentiodynamic polarization and linear polarization resistance (LPR techniques. RS showed maximum inhibition efficiency (η%, 97% at 0.2 g L−1. Potentiodynamic polarization curves justified that all the inhibitors are mixed-type. Surface morphology of AA is carried by scanning electron microscopy (SEM and atomic force microscopy (AFM.

  6. Recoil-free Fraction in Amorphous and Nanocrystalline Aluminium Based Alloys

    Science.gov (United States)

    Sitek, Jozef

    2008-10-01

    Aluminium based rapidly quenched alloys of nominal composition Al90Fe7Nb3 and Al94Fe2V4 were studied by Mössbauer spectroscopy. We have measured the recoil-free fraction and thermal shift at room and liquid nitrogen temperature. The frequency modes of atomic vibrations were determined and consequently the characteristic Debye temperature was derived. Characteristic temperature calculated from f-factor was lower than those fitted from second order Doppler shift. This indicates the presence of different frequency modes for amorphous and nanocrystalline states.

  7. Hot-crack test for aluminium alloys welds using TIG process

    Science.gov (United States)

    Niel, A.; Deschaux-Beaume, F.; Bordreuil, C.; Fras, G.

    2010-06-01

    Hot cracking is a critical defect frequently observed during welding of aluminium alloys. In order to better understand the interaction between cracking phenomenon, process parameters, mechanical factors and microstructures resulting from solidification after welding, an original hot-cracking test during welding is developed. According to in-situ observations and post mortem analyses, hot cracking mechanisms are investigated, taking into account the interaction between microstructural parameters, depending on the thermal cycles, and mechanical parameters, depending on geometry and clamping conditions of the samples and on the thermal field on the sample. Finally, a process map indicating the limit between cracking and non-cracking zones according to welding parameters is presented.

  8. Supersonic laser spray of aluminium alloy on a ceramic substrate

    International Nuclear Information System (INIS)

    Riveiro, A.; Lusquinos, F.; Comesana, R.; Quintero, F.; Pou, J.

    2007-01-01

    Applying a ceramic coating onto a metallic substrate to improve its wear resistance or corrosion resistance has attracted the interest of many researchers during decades. However, only few works explore the possibility to apply a metallic layer onto a ceramic material. This work presents a novel technique to coat ceramic materials with metals: the supersonic laser spraying. In this technique a laser beam is focused on the surface of the precursor metal in such a way that the metal is transformed to the liquid state in the beam-metal interaction zone. A supersonic jet expels the molten material and propels it to the surface of the ceramic substrate. In this study, we present the preliminary results obtained using the supersonic laser spray to coat a commercial cordierite ceramic plate with an Al-Cu alloy using a 3.5 kW CO 2 laser and a supersonic jet of Argon. Coatings were characterized by scanning electron microscopy (SEM) and interferometric profilometry

  9. Decomposition in aluminium alloys: diffuse scattering and crystal modelling

    International Nuclear Information System (INIS)

    Aslam-Malik, A.

    1995-01-01

    In the present study the microstructure of metastable precipitates in Al-Ag and Al-Cu, so called pre-precipitates or Guinier-Preston (GP) zones, was investigated. In both systems important aspects of the microstructure are still controversially discussed. In Al-Ag two forms of GP zones are suggested; depending on the aging temperatures above or below about 443 K, ε- or η-zones should evolve. Differences between these two types of zones may be due to differences in internal order and/or composition. In Al-Cu the characterization of GP I zones is difficult because of the strong atomic displacements around the zones. The proper separation of short-range order and displacement scattering within a diffuse scattering experiment is still under discussion. The technique used to determine the short-range order in both alloys was diffuse scattering with neutrons and X-rays. To separate short-range order and displacement scattering, the methods of Georgopoulos-Cohen (X-ray scattering) and Borie-Sparks (neutron scattering) were used. Of main importance is the optimization of the scattering contrast and thus the scattering contribution due to short-range order. Short-range order scattering is rationalized in terms of pair correlations. Crystals may subsequently be modelled to visualize the microstructure. The Al-Ag system was investigated by diffuse X-ray wide-angle scattering and small-angle neutron scattering. The small-angle neutron scattering measurement was necessary since the GP zones in Al-Ag are almost spherical and the main scattering contribution is found close to the origin of reciprocal space. The small-angle scattering is not that important in the case of Al-Cu because the main scattering extends along (100) owing to the planar character of the GP I zones on (100) lattice planes. (author) 24 figs., 10 tabs., refs

  10. Mechanical Behaviour Investigation Of Aluminium Alloy Tailor Welded Blank Developed By Using Friction Stir Welding Technique

    Science.gov (United States)

    Dwi Anggono, Agus; Sugito, Bibit; Hariyanto, Agus; Subroto; Sarjito

    2017-10-01

    The objective on the research was to investigate the mechanical properties and microstructure of tailor welded blank (TWB) made from AA6061-T6 and AA1100 using friction stir welding (FSW) process. Due to the dissimilar mechanical properties of the two aluminium alloys, microhardness test was conducted to measure the hardness distribution across the weld nugget. The mixing of two distinct materials was influenced by tool rotation speed. Therefore, microstructure analysis was carried out to investigate the grain size and shape. The grain size of AA6061-T6 has increased in the heat affected zone (HAZ) while for AA1100 has decreased. In the weld nugget, it has found a hook defects in the dissimilar aluminium joining. By using monotonic tensile load, the different weld line direction was observed with the expansion in tool rotation. The joints failure were consistently on the area of AA1100 series. Furthermore, two specimens were investigated, one through the dissimilar aluminium and the other through similiar material. Inspection of the weld nugget hardness was shown that nonhomogen material intermixing during the stiring process as confirmed by microhardness measurement.

  11. Relation between feeding mechanisms and solidification mode in 380 aluminium alloy with different iron contents

    International Nuclear Information System (INIS)

    Tovio, D. O.; Gonzalez, A.C.; Mugica, G. W.; Cuyas, J. C.

    2003-01-01

    In the present work the effect of iron (0.15, 0.42 and 0.86%) content in feeding mechanisms for 380 aluminium alloy has been studied. The feeding capacity has been evaluated by a device that produces a barrier removable to allowing the movement of the inter dendritic liquid. The results show the flow of different quantity of liquid, it depends of the temperature of operating the device and of the iron content. For minimum and maximum iron content, the inter dendritic and bursts feeding mechanisms are fundamentally involved, for 0.42% of iron the feeding mechanisms was the inter dendritic. The authors establish this behavior by the solidification mode of alloy, which promotes the presence of particles of Si or plates of b-Al 3 FeDi phase, in the inter dendritic channels and produce the different feeding mechanisms. (Author) 15 refs

  12. Comparison of corrosion behaviour of friction stir processed and laser melted AA 2219 aluminium alloy

    International Nuclear Information System (INIS)

    Surekha, K.; Murty, B.S.; Prasad Rao, K.

    2011-01-01

    Highlights: → Poor corrosion resistance of AA 2219 can be improved by surface treatments. → FSP and LM leads to dissolution of second phase particles. → No literature available on comparison of corrosion behaviour after FSP and LM. → The study implies FSP is as good as LM in improving the corrosion resistance of AA 2219. -- Abstract: Dissolution of second phase particles (CuAl 2 ) present in AA 2219 aluminium improves the corrosion resistance of the alloy. Two surface treatment techniques, viz., solid state friction stir processing and fusion based laser melting lead to the reduction in CuAl 2 content and the effect of these processes on the corrosion behaviour of the alloy is compared in this study. Potentiodynamic polarization and electrochemical impedance spectroscopy tests were carried out to compare corrosion behaviour. The corrosion resistance achieved by friction stir processing is comparable to that obtained by the laser melting technique.

  13. Complex deformation routes for direct recycling aluminium alloy scrap via industrial hot extrusion

    Science.gov (United States)

    Paraskevas, Dimos; Kellens, Karel; Kampen, Carlos; Mohammadi, Amirahmad; Duflou, Joost R.

    2018-05-01

    This paper presents the final results of an industrial project, aiming for direct hot extrusion of wrought aluminium alloy scrap at an industrial scale. Two types of complex deformation/extrusion routes were tested for the production of the same profile, starting from AA6060 scrap in form of machining chips. More specifically scrap-based billets were extruded through: a 2-porthole and a 4-porthole die-set, modified for enhanced scrap consolidation and grain refinement. For comparison reasons, cast billets of the same alloy were extruded through the modified 2-porthole die set. The tensile testing results as well as microstructural investigations show that the 4-porthole extrusion route further improves scrap consolidation compared to the 2-porthole die output. The successful implementation of solid state recycling, directly at industrial level, indicates the technological readiness level of this research.

  14. TIG and MIG welding of 6061 and 7020 aluminium alloys. Microstructural studies and mechanical properties

    International Nuclear Information System (INIS)

    Gomez de Salazar, J.M.; Urena, A.; Villauriz, E.; Manzanedo, S.; Barrena, I.

    1998-01-01

    The aluminium alloys of the 6XXX and 7XXX series, are actually considered of medium and high strength, and are been profusely used in different industries such as aeronautical, automotive, etc.However, its wide application as structural material needs of the proper development of their joining process. The present work describes the results obtained from the microstructural evaluation, both with optical and scanning electronic micros copies (OM) and SEM), and of the mechanical one (hardness changes) of the weld produced in the alloys using different arc welding techniques: FTAW (TIG) and GMAW (MIG). For the last one, a filler metal with a composition of Al-5Mg, AWS denomination A5.10-92 (AA5356), has been used. (Author) 5 refs

  15. Influence of Process Parameters on the Quality of Aluminium Alloy EN AW 7075 Using Selective Laser Melting (SLM)

    Science.gov (United States)

    Kaufmann, N.; Imran, M.; Wischeropp, T. M.; Emmelmann, C.; Siddique, S.; Walther, F.

    Selective laser melting (SLM) is an additive manufacturing process, forming the desired geometry by selective layer fusion of powder material. Unlike conventional manufacturing processes, highly complex parts can be manufactured with high accuracy and little post processing. Currently, different steel, aluminium, titanium and nickel-based alloys have been successfully processed; however, high strength aluminium alloy EN AW 7075 has not been processed with satisfying quality. The main focus of the investigation is to develop the SLM process for the wide used aluminium alloy EN AW 7075. Before process development, the gas-atomized powder material was characterized in terms of statistical distribution: size and shape. A wide range of process parameters were selected to optimize the process in terms of optimum volume density. The investigations resulted in a relative density of over 99%. However, all laser-melted parts exhibit hot cracks which typically appear in aluminium alloy EN AW 7075 during the welding process. Furthermore the influence of processing parameters on the chemical composition of the selected alloy was determined.

  16. Influences of pulsed current tungsten inert gas welding parameters on the tensile properties of AA 6061 aluminium alloy

    International Nuclear Information System (INIS)

    Senthil Kumar, T.; Balasubramanian, V.; Sanavullah, M.Y.

    2007-01-01

    Medium strength aluminium alloy (Al-Mg-Si alloy) has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to-weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. In any structural application of this alloy consideration its weldability is of utmost importance as welding is largely used for joining of structural components. The preferred welding process of aluminium alloy is frequently tungsten inert gas (TIG) welding due to its comparatively easier applicability and better economy. In the case of single pass TIG welding of thinner section of this alloy, the pulsed current has been found beneficial due to its advantages over the conventional continuous current process. The use of pulsed current parameters has been found to improve the mechanical properties of the welds compared to those of continuous current welds of this alloy due to grain refinement occurring in the fusion zone. Many considerations come into the picture and one need to carefully balance various pulse current parameters to arrive at an optimum combination. Hence, in this investigation an attempt has been made to study the influence of pulsed current TIG welding parameters on tensile properties of AA 6061 aluminium alloy weldments

  17. An improved billet on billet extrusion process of continuous aluminium alloy shapes for cryogenic applications in the Compact Muon Solenoid experiment

    CERN Document Server

    Tavares, S S

    2003-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments being designed in the framework of the Large Hadron Collider accelerator at CERN. CMS will contain the largest and the most powerful superconducting solenoid magnet ever built in terms of stored energy. It will work at 4.2 K, will have a magnetic length of 12.5 m, with a free bore of 6m and will be manufactured as a layered and modular structure of NbTi cables embedded in a high purity (99.998%) Al- stabiliser. Each layer consists of a wound continuous length of 2.55 km. In order to withstand the high electromagnetic forces, two external aluminium alloy reinforcing sections are foreseen. These reinforcements, of 24 mm multiplied by 18 mm cross-section, will be continuously electron beam (EB) welded to the pure Al-stabiliser. The alloy EN AW-6082 has been selected for the reinforcements due to its excellent extrudability, high strength in the precipitation hardened state, high toughness and strength at cryogenic temperatures and ready EB weldability. Ea...

  18. Development and characterization of fatigue resistant Aramid reinforced aluminium laminates (ARALL) for fatigue Critical aircraft components

    Science.gov (United States)

    Qaiser, M. H.; Umar, S.; Nauman, S.

    2014-06-01

    The structural weight of an aircraft has always been a controlling parameter that governs its fuel efficiency and transport capacity. In pursuit of achieving light-weight aircraft structures, high design stress levels have to be adopted and materials with high specific strength such as Aluminum etc. are to be deployed. However, an extensive spectrum of fatigue load exists at the aircraft wings and other aerodynamic components that may cause initiation and propagation of fatigue cracks and concludes in a catastrophic rupture. Fatigue is therefore the limiting design parameter in such cases and materials with high fatigue resistance are then required. A major improvement in the fatigue behavior was observed by laminating Kevlar fibers with Aluminum using epoxy. ARALL (Aramid Reinforced ALuminum Laminates) is a fatigue resistant hybrid composite that consists of layers of thin high strength aluminum alloy sheets surface bonded with aramid fibers. The intact aramid fibers tie up the fatigue cracks, thus reducing the stress intensity factor at the crack tip as a result of which the fatigue properties of can be enhanced with orders of magnitude as compared to monolithic high strength Aluminum alloy sheets. Significant amount of weight savings can be achieved in fatigue critical components in comparison with the traditional materials used in aircraft.

  19. Development and characterization of fatigue resistant Aramid reinforced aluminium laminates (ARALL) for fatigue Critical aircraft components

    International Nuclear Information System (INIS)

    Qaiser, M H; Umar, S; Nauman, S

    2014-01-01

    The structural weight of an aircraft has always been a controlling parameter that governs its fuel efficiency and transport capacity. In pursuit of achieving light-weight aircraft structures, high design stress levels have to be adopted and materials with high specific strength such as Aluminum etc. are to be deployed. However, an extensive spectrum of fatigue load exists at the aircraft wings and other aerodynamic components that may cause initiation and propagation of fatigue cracks and concludes in a catastrophic rupture. Fatigue is therefore the limiting design parameter in such cases and materials with high fatigue resistance are then required. A major improvement in the fatigue behavior was observed by laminating Kevlar fibers with Aluminum using epoxy. ARALL (Aramid Reinforced ALuminum Laminates) is a fatigue resistant hybrid composite that consists of layers of thin high strength aluminum alloy sheets surface bonded with aramid fibers. The intact aramid fibers tie up the fatigue cracks, thus reducing the stress intensity factor at the crack tip as a result of which the fatigue properties of can be enhanced with orders of magnitude as compared to monolithic high strength Aluminum alloy sheets. Significant amount of weight savings can be achieved in fatigue critical components in comparison with the traditional materials used in aircraft

  20. Development and characterization of fatigue resistant aramid reinforced aluminium laminates (ARALL) for fatigue critical aircraft components

    International Nuclear Information System (INIS)

    Qaiser, M. H.; Umar, S.; Nauman, S.

    2013-01-01

    The structural weight of an aircraft has always been a controlling parameter that governs its fuel efficiency and transport capacity. In pursuit of achieving light-weight aircraft structures, high design stress levels have to be adopted and materials with high specific strength such as Aluminum etc. are to be deployed. However, an extensive spectrum of fatigue load exists at the aircraft wings and other aerodynamic components that may cause initiation and propagation of fatigue cracks and concludes in a catastrophic rupture. Fatigue is therefore the limiting design parameter in such cases and materials with high fatigue resistance are then required. A major improvement in the fatigue behavior was observed by laminating Kevlar fibers with Aluminum using epoxy. ARALL (Aramid Reinforced Aluminum Laminates) is a fatigue resistant hybrid composite that consists of layers of thin high strength aluminum alloy sheets surface bonded with aramid fibers. The intact aramid fibers tie up the fatigue cracks, thus reducing the stress intensity factor at the crack tip as a result of which the fatigue properties of can be enhanced with orders of magnitude as compared to monolithic high strength Aluminum alloy sheets. Significant amount of weight savings can be achieved in fatigue critical components in comparison with the traditional materials used in aircraft. (author)

  1. Investigating the Acid Failure of Aluminium Alloy in 2 M Hydrochloric Acid Using Vernonia amygdalina

    Directory of Open Access Journals (Sweden)

    Olugbenga A. Omotosho

    2012-04-01

    Full Text Available The acid failure of aluminium alloy in 2 M hydrochloric acid solution in the presence of Vernonia amygdalina extract was investigated using gasometric technique. Aluminium alloy coupons of dimension 4 cm by 1 cm were immersed in test solutions of free acid and also those containing extract volumes of 2, 3, 4 and 5 cm3 at ambient temperature for 30 minutes. The volumes of hydrogen gas evolved as a result of the rate of reaction were recorded and analyzed. Analysis revealed that maximum inhibitor efficiency which corresponds to the lowest corrosion rate was obtained at optimum inhibitor volumes of 5 cm3, with reduction in the corrosion rate observed to follow in order of increasing extract volumes. Adsorption study revealed that Temkin isotherm best described the metal surface interaction with the extract phytochemicals, with 12 minutes becoming the best exposure time for the phytochemicals to adsorb to the metal surface at all volumes. Statistical modelling of the corrosion rate yielded an important relationship suitable for estimating corrosion rate values once volumes of the extract is known. Microstructural studies, showed an indirect relationship between crack growth rates and extract volumes, while consistency of the irregular intermetallic phases increases with increasing extract volumes.

  2. Crack growth behaviour of aluminium wrought alloys in the Very High Cycle Fatigue regime

    Directory of Open Access Journals (Sweden)

    Bülbül Fatih

    2018-01-01

    Full Text Available Investigations have shown that in the regime of Very High Cycle Fatigue (VHCF “natural” crack initiation often takes place underneath the material surface leading to crack propagation without contact to atmospheric components. In order to elucidate the environmental damage contribution and its effect on the VHCF long crack propagation, fatigue experiments with alternating environment (vacuum and laboratory air were performed. An ultrasonic fatigue testing system (USFT equipped with a small vacuum chamber was applied that enables the in-situ examination of the long fatigue crack propagation at a resonance frequency of about 20 kHz by using a long distance microscope. By means of the Focused-Ion-Beam technique, micro-notches were prepared in the USFT specimens. The tests were carried out on the aluminium alloys EN-AW 6082 and 5083 in different conditions. It has been found that the atmosphere has a significant influence on the VHCF long crack propagation which manifests itself in the crack path as well as in the crack growth rates. Because of pronounced single sliding in vacuum, shear-stress-controlled crack propagation was detected whereas in laboratory air normal-stress-controlled crack propagation occurred. Furthermore, it has been proven that the secondary precipitation state of the aluminium alloy significantly influences the VHCF long crack propagation in vacuum.

  3. Modeling Dynamic Anisotropic Behaviour and Spall Failure in Commercial Aluminium Alloys AA7010

    Science.gov (United States)

    Mohd Nor, M. K.; Ma'at, N.; Ho, C. S.

    2018-04-01

    This paper presents a finite strain constitutive model to predict a complex elastoplastic deformation behaviour involves very high pressures and shockwaves in orthotropic materials of aluminium alloys. The previous published constitutive model is used as a reference to start the development in this work. The proposed formulation that used a new definition of Mandel stress tensor to define Hill's yield criterion and a new shock equation of state (EOS) of the generalised orthotropic pressure is further enhanced with Grady spall failure model to closely predict shockwave propagation and spall failure in the chosen commercial aluminium alloy. This hyperelastic-plastic constitutive model is implemented as a new material model in the Lawrence Livermore National Laboratory (LLNL)-DYNA3D code of UTHM's version, named Material Type 92 (Mat92). The implementations of a new EOS of the generalised orthotropic pressure including the spall failure are also discussed in this paper. The capability of the proposed constitutive model to capture the complex behaviour of the selected material is validated against range of Plate Impact Test data at 234, 450 and 895 ms-1 impact velocities.

  4. Deep surface rolling for fatigue life enhancement of laser clad aircraft aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, W., E-mail: wyman.zhuang@dsto.defence.gov.au [Aerospace Division, Defence Science and Technology Organisation, 506 Lorimer Street, Fishermans Bend, Victoria 3207 (Australia); Liu, Q.; Djugum, R.; Sharp, P.K. [Aerospace Division, Defence Science and Technology Organisation, 506 Lorimer Street, Fishermans Bend, Victoria 3207 (Australia); Paradowska, A. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2232 (Australia)

    2014-11-30

    Highlights: • Deep surface rolling as a post-repair enhancement technology was applied to the laser cladded 7075-T651 aluminium alloy specimens that simulated corrosion damage blend-out repair. • The residual stresses induced by the deep surface rolling process were measured. • The deep surface rolling process can introduce deep and high magnitude compressive residual stresses beyond the laser clad and substrate interface. • Spectrum fatigue test showed the fatigue life was significantly increased by deep surface rolling. - Abstract: Deep surface rolling can introduce deep compressive residual stresses into the surface of aircraft metallic structure to extend its fatigue life. To develop cost-effective aircraft structural repair technologies such as laser cladding, deep surface rolling was considered as an advanced post-repair surface enhancement technology. In this study, aluminium alloy 7075-T651 specimens with a blend-out region were first repaired using laser cladding technology. The surface of the laser cladding region was then treated by deep surface rolling. Fatigue testing was subsequently conducted for the laser clad, deep surface rolled and post-heat treated laser clad specimens. It was found that deep surface rolling can significantly improve the fatigue life in comparison with the laser clad baseline repair. In addition, three dimensional residual stresses were measured using neutron diffraction techniques. The results demonstrate that beneficial compressive residual stresses induced by deep surface rolling can reach considerable depths (more than 1.0 mm) below the laser clad surface.

  5. Deep surface rolling for fatigue life enhancement of laser clad aircraft aluminium alloy

    International Nuclear Information System (INIS)

    Zhuang, W.; Liu, Q.; Djugum, R.; Sharp, P.K.; Paradowska, A.

    2014-01-01

    Highlights: • Deep surface rolling as a post-repair enhancement technology was applied to the laser cladded 7075-T651 aluminium alloy specimens that simulated corrosion damage blend-out repair. • The residual stresses induced by the deep surface rolling process were measured. • The deep surface rolling process can introduce deep and high magnitude compressive residual stresses beyond the laser clad and substrate interface. • Spectrum fatigue test showed the fatigue life was significantly increased by deep surface rolling. - Abstract: Deep surface rolling can introduce deep compressive residual stresses into the surface of aircraft metallic structure to extend its fatigue life. To develop cost-effective aircraft structural repair technologies such as laser cladding, deep surface rolling was considered as an advanced post-repair surface enhancement technology. In this study, aluminium alloy 7075-T651 specimens with a blend-out region were first repaired using laser cladding technology. The surface of the laser cladding region was then treated by deep surface rolling. Fatigue testing was subsequently conducted for the laser clad, deep surface rolled and post-heat treated laser clad specimens. It was found that deep surface rolling can significantly improve the fatigue life in comparison with the laser clad baseline repair. In addition, three dimensional residual stresses were measured using neutron diffraction techniques. The results demonstrate that beneficial compressive residual stresses induced by deep surface rolling can reach considerable depths (more than 1.0 mm) below the laser clad surface

  6. Numerical analysis of heat treatment of TiCN coated AA7075 aluminium alloy

    Science.gov (United States)

    Srinath, M. K.; Prasad, M. S. Ganesha

    2018-04-01

    The Numerical analysis of heat treatments of TiCN coated AA7075 aluminium alloys is presented in this paper. The Convection-Diffusion-Reaction (CDR) equation with solutions in the Streamlined-Upward Petrov-Galerkin (SUPG) method for different parameters is provided for the understanding of the process. An experimental process to improve the surface properties of AA-7075 aluminium alloy was attempted through the coatings of TiCN and subsequent heat treatments. From the experimental process, optimized temperature and time was obtained which gave the maximum surface hardness and corrosion resistance. The paper gives an understanding and use of the CDR equation for application of the process. Expression to determine convection, diffusion and reaction parameters are provided which is used to obtain the overall expression of the heat treatment process. With the substitution of the optimized temperature and time, the governing equation may be obtained. Additionally, the total energy consumed during the heat treatment process is also developed to give a mathematical formulation of the energy consumed.

  7. Effect of the temperature and the chlorine pressure, over the aluminium chlorides obtained by direct chlorination of the 6061 alloy

    International Nuclear Information System (INIS)

    Alvarez, Fabiola J.; Bohe, Ana E.; Pasquevich, Daniel M.

    2003-01-01

    The aluminium chloride is synthesized by direct chlorination of aluminium, in agreement with the following reaction: Al(s) + 3/2 Cl 2 AlCl 3 (s,g).The present work focuses on the preparation of aluminium chlorides by two methods: (a) Chlorination of 6061 aluminium alloy with gaseous chlorine in sealed containers, filled with different pressures of gas, from 0.8 to 74 Kpa and in the range of temperature between 200 0 and 500 0 C.(b) Chlorination of the same alloy in chlorine flow between 150 0 and 400 0 C.In the sealed systems, the hexahydrated aluminium trichloride predominated over the anhydrous form. For pressures lower than 14 Kpa and temperatures under 250 0 C, the chloride didn't appear.The residues were rich in aluminium, chlorine and magnesium.In the other systems, the anhydrous chloride was found in the areas of the reactor of temperatures above 100 0 C, for all the thermal treatments. The waste was composed by CrCl 3 and AlCl 3 .6H 2 O.The influence of the chlorine pressures and the heating temperature over the characteristics of the product, was studied.The characterization techniques were x-ray diffraction and energy dispersive spectroscopy, and the evolution of the structure was followed by scanning electron microscopy

  8. Isoelectronic substitutions and aluminium alloying in the Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor

    Science.gov (United States)

    von Rohr, Fabian O.; Cava, Robert J.

    2018-03-01

    High-entropy alloys (HEAs) are a new class of materials constructed from multiple principal elements statistically arranged on simple crystallographic lattices. Due to the large amount of disorder present, they are excellent model systems for investigating the properties of materials intermediate between crystalline and amorphous states. Here we report the effects of systematic isoelectronic replacements, using Mo-Y, Mo-Sc, and Cr-Sc mixtures, for the valence electron count 4 and 5 elements in the body-centered cubic (BCC) Ta-Nb-Zr-Hf-Ti high-entropy alloy (HEA) superconductor. We find that the superconducting transition temperature Tc strongly depends on the elemental makeup of the alloy, and not exclusively its electron count. The replacement of niobium or tantalum by an isoelectronic mixture lowers the transition temperature by more than 60%, while the isoelectronic replacement of hafnium, zirconium, or titanium has a limited impact on Tc. We further explore the alloying of aluminium into the nearly optimal electron count [TaNb] 0.67(ZrHfTi) 0.33 HEA superconductor. The electron count dependence of the superconducting Tc for (HEA)Al x is found to be more crystallinelike than for the [TaNb] 1 -x(ZrHfTi) x HEA solid solution. For an aluminum content of x =0.4 the high-entropy stabilization of the simple BCC lattice breaks down. This material crystallizes in the tetragonal β -uranium structure type and superconductivity is not observed above 1.8 K.

  9. Reinforcement with alumina particles at the interface region of AA6101-T6 and AA1350 alloys during friction stir welding

    Science.gov (United States)

    Ashok Kumar, R.; Thansekhar, M. R.

    2018-04-01

    This paper deals the combinational effect of friction stir welding and friction stir processing on dissimilar AA6101-T6 and AA1350 aluminium alloys. For that, alumina particles are reinforced at interface region of AA6101-T6 and AA1350 aluminium alloys. Friction Stir Welding and Friction Stir Processing are done simultaneously for various sizes of groove. To analyze the welding quality and surface modifications, mechanical, wear and microstructural tests are carried out. Among these, smallest groove of 0.5 mm width and 1 mm depth reveals highest tensile and bending strengths and largest groove of 2 mm width and 3 mm depth gives maximum hardness and wear resistance. Taguchi technique shows that groove width is most influencing parameter. Developed second order models with interaction predict the responses with minimum error.

  10. Influence of reinforcement proportion and matrix composition on pitting corrosion behaviour of cast aluminium matrix composites (A3xx.x/SiCp)

    International Nuclear Information System (INIS)

    Pardo, A.; Merino, M.C.; Merino, S.; Viejo, F.; Carboneras, M.; Arrabal, R.

    2005-01-01

    The influence of silicon carbide (SiCp) proportion and matrix composition on four aluminium metal matrix composites (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p) immersed in 1-3.5 wt% NaCl at 22 deg C was investigated by potentiodynamic polarization. The kinetics of the corrosion process was studied on the basis of gravimetric measurements. The nature of corrosion products was analysed by scanning electron microscopy (SEM) and low angle X-ray diffraction (XRD). The corrosion damage in Al/SiCp composites was caused by pitting attack and by nucleation and growth of Al 2 O 3 . 3H 2 O on the material surface. The main attack nucleation sites were the interface region between the matrix and the reinforcement particles. The corrosion process was influenced more by the concentration of alloy elements in the matrix than by the proportion of SiCp reinforcement and saline concentration

  11. Influence of reinforcement proportion and matrix composition on pitting corrosion behaviour of cast aluminium matrix composites (A3xx.x/SiCp)

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, A. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain)]. E-mail: anpardo@quim.ucm.es; Merino, M.C. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain); Merino, S. [Departamento de Tecnologia Industrial, Universidad Alfonso X El Sabio, 28691, Villanueva de la Canada, Madrid (Spain); Viejo, F. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain); Carboneras, M. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain); Arrabal, R. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain)

    2005-07-01

    The influence of silicon carbide (SiCp) proportion and matrix composition on four aluminium metal matrix composites (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p) immersed in 1-3.5 wt% NaCl at 22 deg C was investigated by potentiodynamic polarization. The kinetics of the corrosion process was studied on the basis of gravimetric measurements. The nature of corrosion products was analysed by scanning electron microscopy (SEM) and low angle X-ray diffraction (XRD). The corrosion damage in Al/SiCp composites was caused by pitting attack and by nucleation and growth of Al{sub 2}O{sub 3} . 3H{sub 2}O on the material surface. The main attack nucleation sites were the interface region between the matrix and the reinforcement particles. The corrosion process was influenced more by the concentration of alloy elements in the matrix than by the proportion of SiCp reinforcement and saline concentration.

  12. Effect of smelt aluminium on mechanical properties of steels

    International Nuclear Information System (INIS)

    Ryabov, V.R.; Dykhno, I.S.; Deev, G.F.; Karikh, V.V.

    1987-01-01

    Effect of smelt aluminium on mechanical properties of armco-iron and 12 Kh18N10T steel is studied. It is stated that in smelt aluminium and aluminium alloy contact with armco-iron the sample ductility is decreased. Corrosion effect of smelt alluminium on (18Kh15N5AM3) steel in the form of reinforced wire in aluminium-steel KAS-1A composite material is investigted. It is stated in experiment that during smelt alluminium-steel contact interaction of heterogeneous phases takes place

  13. Comparative study on laser welding and TIG welding of semi-solid high pressure die cast A356 aluminium alloy

    CSIR Research Space (South Africa)

    Govender, G

    2007-07-01

    Full Text Available components. The low porosity levels in SSM high pressure die castings (HPDC) improves the weldability of these components. The aim of the current research was to perform a comparative study of laser and TIG welding of SSM HPDC aluminium alloy A356. SSM...

  14. Neutralization of the negative influence of iron and silicon on the mechanical properties of aluminium casting alloys

    International Nuclear Information System (INIS)

    Zolotorevsky, V.S.; Axenov, A.A.; Belov, N.A.

    1990-01-01

    In most of casting aluminium alloys iron is a harmful impurity due to the appearance of rough particles with needle, plate or sceleton shapes of intermetallic compounds during crystallization. As a result of it the plasticity, fracture toughness and sometimes the strength are decreased

  15. Experimental and numerical analysis of in- and out- of plane constraint effects on fracture parameters: Aluminium alloy 2024

    Czech Academy of Sciences Publication Activity Database

    Seitl, Stanislav; Hutař, Pavel; García, T.; Canteli, A.

    7 2013, č. 7 (2013), s. 53-64 ISSN 1802-680X Grant - others:Interní podpora AV ČR(CZ) M100411204 Keywords : LELM * stress intensity tensor * constraint * aluminium alloy * plane strain * plane stress Subject RIV: JL - Materials Fatigue, Friction Mechanics

  16. Surface modification of 2014 aluminium alloy-Al2O3 particles composites by nickel electrochemical deposition

    International Nuclear Information System (INIS)

    Molina, J.M.; Saravanan, R.A.; Narciso, J.; Louis, E.

    2004-01-01

    A method to modify the surface of aluminium matrix composites (AMC) by electrochemical nickel deposition has been developed. Deposition was carried out in a stirred standard Watt's bath, whereas potential and time were varied to optimize coating characteristics. The method, that allowed to overcome the serious difficulties associated to electrochemical deposition of an inherently inhomogeneous material, was used to nickel coat composites of 2014 aluminium alloy-15 vol.% Al 2 O 3 particles. Coats with a good adherence and up to 60 μm thick were easily obtained. In order to improve surface properties, the coated composite was subjected to rather long (from 10 to 47.5 h) heat treatments at a temperature of 520 deg,C. The heat treatments improved the uniformity of the deposited layer and promoted the formation of Al-Ni intermetallics (mainly Al 3 Ni 2 , as revealed by X-ray diffraction and energy-dispersive X-ray analysis (EDX)). Experimental results indicate that growth of the intermetallic layer is diffusion limited

  17. High-Strength Aluminium Alloys and Their Use in Foundry Industry of Nickel Superalloys

    Directory of Open Access Journals (Sweden)

    Pysz S.

    2014-08-01

    Full Text Available Of great importance in the selection of materials for cast structures is keeping a proper balance between the mechanical and plastic properties, while preserving the relevant casting properties. This study has been devoted to an analysis of the choice and application of high-strength aluminium-based alloys maintaining sufficient level of casting properties. The high level of tensile strength (Rm > 500 MPa matched with satisfactory elongation (A > 3% is important because materials of this type are used for cast parts operating in the aerospace, automotive, and military industries. These beneficial relationships between the high tensile strength and toughness are relatively easy to obtain in the Al-Zn-Mg-Cu alloys subjected to plastic forming and proper heat treatment. In gravity cast products, on the other hand, whether poured into sand moulds or metal moulds (dies, obtaining this favourable combination of properties poses a number of research problems (mostly resulting from the alloy chemical composition as well as technical and technological difficulties.

  18. Effect of regimes of equal-channel angular pressing on the superplasticity of aluminium alloy 1420

    International Nuclear Information System (INIS)

    Islamgaliev, R.K.; Yunusova, N.F.; Valiev, R.Z.

    2002-01-01

    Investigation results on the influence of conditions of equal-channel angular pressing (EAP) on structure and superplasticity of aluminium alloy 1420 (Al-5.5%Mg-2.2%Li-0.12%Zr) are reported. It is revealed that the superplasticity of alloy 1420 is determined not only by fine grains (less than 1 μm), but its structural and phase state as well. The structural phase state is shown to be greatly dependent on EAP conditions. In particular, the structure of specimens prepared using the optimal EAP conditions is characterized by a mean grain size (0.8 μm) of the matrix with predominantly high-angle disorientations as well as by presence of secondary phase Al 2 MgLi and AlLi particles with of 0.3 μm and 0.4 μm size respectively. It is shown that the rods with an optimal structural phase state exhibit record-breaking for the alloy elongation to fracture equal to 1620% at 400 Deg C and at strain rate of 10 -2 s -1 [ru

  19. Characterization of semi-solid processing of aluminium alloy 7075 with Sc and Zr additions

    Energy Technology Data Exchange (ETDEWEB)

    Rogal, Ł., E-mail: l.rogal@imim.pl [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Dutkiewicz, J. [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Atkinson, H.V. [The University of Leicester, Department of Engineering University Road, Leicester, LE1 7RH (United Kingdom); Lityńska-Dobrzyńska, L.; Czeppe, T. [Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, 25 Reymonta St., 30-059 Krakow (Poland); Modigell, M. [RWTH Aachen—Department of Mechanical Process Engineering, 55 Templergraben St., Aachen (Germany)

    2013-09-15

    For thixoforming (semi-solid processing) it is necessary to have a fine globular microstructure in a semi-solid range. Here this has been obtained for 7075 aluminium alloy by addition of modifying agents: 0.5 weight % of scandium and zirconium. The thixoforming process was carried out at 632 °C which gave about 23 volume % of liquid phase. The microstructure of the thixo-formed part (a rotor) consisted of globular grains surrounded by precipitates of secondary phase. The average hardness of thixo-formed parts was 105 HV{sub 5} and the tensile strength 300 MPa. T6 heat treatments were performed with solutionisation at 450 °C for 30 min and 10 h. In both cases the ageing time was set as 18 h at 120 °C. The heat treatments led to an increase in average tensile strength up to 495 MPa. Transmission Electron Microscopy (TEM) analysis enabled the identification of precipitates of the metastable dispersoids of L1{sub 2}–Al{sub 3} (Zr, Sc) and η′ (MgZn{sub 2}) phases in the alloy after the thixoforming and T6 treatment. The measurements of rheological properties of 7075Al alloy with Sc and Zr additions in the semi-solid range indicated an increase of particle size and spheroidization leading to an observable decrease of viscosity during isothermal shearing. A shear rate jump experiment showed that with increasing shear rate the viscosity rapidly falls.

  20. Improvement of the oxidation resistance of Tribaloy T-800 alloy by the additions of yttrium and aluminium

    International Nuclear Information System (INIS)

    Zhang, Y.-D.; Zhang, C.; Lan, H.; Hou, P.Y.; Yang, Z.-G.

    2011-01-01

    Research highlights: → The additions of yttrium (Y) reduced the oxidation rate of Tribaloy T-800 alloy. → Y promoted selective oxidation of Cr due to refinement of alloy phase size. → The oxidation rate was further reduced by Y plus Al with a protective Al 2 O 3 scale. → The positive effect of Y and Al being more pronounced at the higher temperature. - Abstract: The microstructures and oxidation behaviour of the modified Tribaloy T-800 alloys by additions of yttrium and yttrium plus aluminium have been studied. At the presence of yttrium alone, the oxidation rate decreased, and the selective oxidation of chromium was promoted, which was related to the refinement of alloy phase size. The addition of yttrium plus aluminium further reduced the oxidation rate. The selective oxidation of chromium and aluminium were both promoted significantly. The benefits were especially pronounced at 1000 o C, with the formation of protective alumina external layer and no internal oxides, which may be detrimental to the alloy mechanical property.

  1. Effect of rotation speed and welding speed on Friction Stir Welding of AA1100 Aluminium alloy

    Science.gov (United States)

    Raja, P.; Bojanampati, S.; Karthikeyan, R.; Ganithi, R.

    2018-04-01

    Aluminum AA1100 is the most widely used grade of Aluminium due to its excellent corrosion resistance, high ductility and reflective finish, the selected material was welded with Friction Stir Welding (FSW) process on a CNC machine, using a combination of different tool rotation speed (1500 rpm, 2500 rpm, 3500 rpm) and welding speed (10 mm/min, 30 mm/min, 50 mm/min) as welding parameters. The effect of FSW using this welding parameter was studied by measuring the ultimate tensile strength of the welded joints. A high-speed steel tool was prepared for welding the Aluminium AA1100 alloy having an 8mm shoulder diameter and pin dimension of 4mm diameter and 2.8 mm length. The welded joints were tested using the universal testing machine. It was found that Ultimate Tensile Strength of FSW specimen was highest with a value of 98.08 MPa when the weld was performed at rotation speed of 1500 RPM and welding speed of 50 mm/min.

  2. Influence of friction stir welding parameters on properties of 2024 T3 aluminium alloy joints

    Directory of Open Access Journals (Sweden)

    Eramah Abdsalam M.

    2014-01-01

    Full Text Available The aim of this work is to analyse the process of friction stir welding (FSW of 3mm thick aluminium plates made of high strength aluminium alloy - 2024 T3, as well as to assess the mechanical properties of the produced joints. FSW is a modern procedure which enables joining of similar and dissimilar materials in the solid state, by the combined action of heat and mechanical work. This paper presents an analysis of the experimental results obtained by testing the butt welded joints. Tensile strength of the produced joints is assessed, as well as the distribution of hardness, micro-and macrostructure through the joints (in the base material, nugget, heat affected zone and thermo-mechanically affected zone. Different combinations of the tool rotation speed and the welding speed are used, and the dependence of the properties of the joints on these parameters of welding technology is determined. [Projekat Ministarstva nauke Republike Srbije, br. TR 34018 i br. TR 35006

  3. Radiographic and ultrasonic testings of welded joints of 6063 aluminium alloy

    International Nuclear Information System (INIS)

    Oliveira e Silva Mury, A.G. de.

    1980-05-01

    A study on evaluation of weld defects in aluminium butt joints was made in a comparative way through the radiographic and ultrasonic testing. This work was conducted with pipes 5 IPS (6,35 mm thickness) of 6063 aluminium alloy, circumferential TIG welded, due to the difficulty on performing non-destructive testing with this schedule. It was concluded thta ultrasonic testing has adequate sensitivity when setting gain adjustment is made with aid of a reference curve constructed by using a Reference Block (among others studied) with 1,5 mm dia. Hole as reference reflector, and a 5 MHz angle beam search-unit. In this case the ultrasonic testing is more accurate than radiographic testing to detect planar defects like lack of fusion and lack of penetration. Defect sizing by ultrasonic methods employed were 6 and 20 dB drop methods. In spite of your observed limitations concerning the establishment of the real size of defects, the procedure applied was precise for locate and define the weld defects that where found in this study. (author) [pt

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

    Directory of Open Access Journals (Sweden)

    S. Bhowmick

    2015-09-01

    Full Text Available 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 values of H-DLC and W-DLC were 0.15 and 0.20. A lower COF value of 0.11 was observed when W-DLC was tested using lubricant oil incorporating sulphur while the H-DLC’s COF remained almost unchanged. The mechanisms responsible for the low friction of W-DLC observed during lubricated sliding were revealed by studying the compositions of the coating surfaces and the transfer layers formed on 319 Al. Micro-Raman spectroscopy indicated that the transfer layers formed during lubricated sliding of W-DLC incorporated tungsten disulphide (WS2.

  5. Neutron-activation analysis of phosphorus in aluminium-silicon alloys

    International Nuclear Information System (INIS)

    Rajchev, Kh.

    1976-01-01

    Silicon-aluminium alloy samples weighing about 50 mg are irradiated in a nuclear reactor with a neutron flow of 5x10 12 neutrons, cm -2 .s -1 . After a period of one week for decay of the short-lived isotopes, the sample is dissolved in a mixture of nitric and hydrofluoric acid. It is neutralized up to pH 2,5 and the present radioactive two- and three-valent cations are sorbed on chelating ion exchange resin Dowex A1. An ammonium phosphate standard is irradiated in parallel with the sample for qualitative determinations. The quantity of phosphorus is measured in aliquots from the sample and the standard with a liquid counter. The method proposed for separating and determining the phosphorus in silumins ensures practically the full separation of phosphorus (98,5 +- 0,5 %) and a precise determination of microquantities of the element - up to 10 -10 g. (author)

  6. Strain rate effects on mechanical properties in tension of aluminium alloys used in armour applications

    Science.gov (United States)

    Cadoni, E.; Dotta, M.; Forni, D.; Bianchi, S.; Kaufmann, H.

    2012-08-01

    The mechanical properties in tension of two aluminium alloys (AA5059-H131 and AA7039-T651) used in armour applications were determined from tests carried out over a wide range of strain-rates on round specimens. The experimental research was developed in the DynaMat laboratory of the University of Applied Sciences of Southern Switzerland. The target strain rates were set at the following four levels: 10-3, 30, 300 and 1000s-1. The quasi-static tests were performed with a universal electromechanical machine, whereas a hydro-pneumatic machine and a Split Hopkinson Tensile Bar apparatus were used for medium and high strain-rates respectively. The required parameters by the Johnson-Cook constitutive law were also determined.

  7. Multi response optimization of wire-EDM process parameters of ballistic grade aluminium alloy

    Directory of Open Access Journals (Sweden)

    Ravindranadh Bobbili

    2015-12-01

    Full Text Available In the current investigation, a multi response optimization technique based on Taguchi method coupled with Grey relational analysis is planned for wire-EDM operations on ballistic grade aluminium alloy for armour applications. Experiments have been performed with four machining variables: pulse-on time, pulse-off time, peak current and spark voltage. Experimentation has been planned as per Taguchi technique. Three performance characteristics namely material removal rate (MRR, surface roughness (SR and gap current (GC have been chosen for this study. Results showed that pulse-on time, peak current and spark voltage were significant variables to Grey relational grade. Variation of performance measures with process variables was modelled by using response surface method. The confirmation tests have also been performed to validate the results obtained by Grey relational analysis and found that great improvement with 6% error is achieved.

  8. A new model for prediction of dispersoid precipitation in aluminium alloys containing zirconium and scandium

    International Nuclear Information System (INIS)

    Robson, J.D.

    2004-01-01

    A model has been developed to predict precipitation of ternary Al 3 (Sc, Zr) dispersoids in aluminium alloys containing zirconium and scandium. The model is based on the classical numerical method of Kampmann and Wagner, extended to predict precipitation of a ternary phase. The model has been applied to the precipitation of dispersoids in scandium containing AA7050. The dispersoid precipitation kinetics and number density are predicted to be sensitive to the scandium concentration, whilst the dispersoid radius is not. The dispersoids are predicted to enrich in zirconium during precipitation. Coarsening has been investigated in detail and it has been predicted that a steady-state size distribution is only reached once coarsening is well advanced. The addition of scandium is predicted to eliminate the dispersoid free zones observed in scandium free 7050, greatly increasing recrystallization resistance

  9. Hot-crack test for aluminium alloys welds using TIG process

    Directory of Open Access Journals (Sweden)

    Deschaux-beaume F.

    2010-06-01

    Full Text Available Hot cracking is a critical defect frequently observed during welding of aluminium alloys. In order to better understand the interaction between cracking phenomenon, process parameters, mechanical factors and microstructures resulting from solidification after welding, an original hot-cracking test during welding is developed. According to in-situ observations and post mortem analyses, hot cracking mechanisms are investigated, taking into account the interaction between microstructural parameters, depending on the thermal cycles, and mechanical parameters, depending on geometry and clamping conditions of the samples and on the thermal field on the sample. Finally, a process map indicating the limit between cracking and non-cracking zones according to welding parameters is presented.

  10. Material Characterization of Dissimilar Friction Stir Spot Welded Aluminium and Copper Alloy

    Science.gov (United States)

    Sanusi, K. O.; Akinlabi, E. T.

    2017-08-01

    In this research study, material characterization of dissimilar friction stir spot welded Aluminium and Copper was evaluated. Rotational speeds of 800 rpm and transverse speeds of 50 mm/min, 150 mm/min and 250 mm/min were used. The total numbers of samples evaluated were nine altogether. The spot welds were characterised by microstructure characterization using optical microscope (OEM) and scanning electron microscopy technique (SEM) by observing the evolution of the microstructure across the weld’s cross-section. lap-shear test of the of the spot weld specimens were also done. From the results, it shows that welding of metals and alloys using Friction stir spot welding is appropriate and can be use in industrial applications.

  11. Experimental characterisation and modelling of deformation- induced microstructure in an A6061 aluminium alloy

    International Nuclear Information System (INIS)

    Kreyca, J F; Falahati, A; Kozeschnik, E

    2016-01-01

    For industry, the mechanical properties of a material in form of flow curves are essential input data for finite element simulations. Current practice is to obtain flow curves experimentally and to apply fitting procedures to obtain constitutive equations that describe the material response to external loading as a function of temperature and strain rate. Unfortunately, the experimental procedure for characterizing flow curves is complex and expensive, which is why the prediction of flow-curves by computer modelling becomes increasingly important. In the present work, we introduce a state parameter based model that is capable of predicting the flow curves of an A6061 aluminium alloy in different heat-treatment conditions. The model is implemented in the thermo-kinetic software package MatCalc and takes into account precipitation kinetics, subgrain formation, dynamic recovery by spontaneous annihilation and dislocation climb. To validate the simulation results, a series of compression tests is performed on the thermo-mechanical simulator Gleeble 1500. (paper)

  12. Experimental characterisation and modelling of deformation- induced microstructure in an A6061 aluminium alloy

    Science.gov (United States)

    Kreyca, J. F.; Falahati, A.; Kozeschnik, E.

    2016-03-01

    For industry, the mechanical properties of a material in form of flow curves are essential input data for finite element simulations. Current practice is to obtain flow curves experimentally and to apply fitting procedures to obtain constitutive equations that describe the material response to external loading as a function of temperature and strain rate. Unfortunately, the experimental procedure for characterizing flow curves is complex and expensive, which is why the prediction of flow-curves by computer modelling becomes increasingly important. In the present work, we introduce a state parameter based model that is capable of predicting the flow curves of an A6061 aluminium alloy in different heat-treatment conditions. The model is implemented in the thermo-kinetic software package MatCalc and takes into account precipitation kinetics, subgrain formation, dynamic recovery by spontaneous annihilation and dislocation climb. To validate the simulation results, a series of compression tests is performed on the thermo-mechanical simulator Gleeble 1500.

  13. Studies of the Action of Grain-Refining Particles in Aluminium Alloys

    Science.gov (United States)

    Schumacher, P.; Greer, A. L.

    Crystallization from a melt and from a metallic glass both occur in an undercooled liquid. In this way identical nucleation mechanisms can operate in the two cases. However, in metallic glasses, unlike conventional solidification at low undercooling, the low atomic mobility permits the resolution and microscopical study of nucleation processes on added particles. Conventional aluminium grain-refiner based on Al-Ti-B has been used to obtain nucleant particles embedded in a glassy matrix of Al85Y8Ni5Co2 (at%). During crystallization from the glassy state, nucleation and growth of α-Al can be observed on TiB2 particles coated with a layer of Al3Ti Empirical relations found in casting practice of Al-alloys, such as excess Ti necessary for grain refinement, can be related to the observed nucleation mechanism, which is found to be very sensitive to both crystallographic and chemical factors.

  14. Microstructure of friction stir welded joints of 2017A aluminium alloy sheets.

    Science.gov (United States)

    Mroczka, K; Dutkiewicz, J; Pietras, A

    2010-03-01

    The present study examines a friction stir welded 2017A aluminium alloy. Transmission electron microscope investigations of the weld nugget revealed the average grain size of 5 microm, moderate density of dislocations as well as the presence of nanometric precipitates located mostly in grains interiors. Scanning electron microscope observations of fractures showed the presence of ductile fracture in the region of the weld nugget with brittle precipitates in the lower part. The microhardness analysis performed on the cross-section of the joints showed fairly small changes; however, after the artificial ageing process an increase in hardness was observed. The change of the joint hardness subject to the ageing process indicates partial supersaturation in the material during friction stir welding and higher precipitation hardening of the joint.

  15. Microstructural evolution and properties of friction stir welded aluminium alloy AA2219

    International Nuclear Information System (INIS)

    Gupta, R. K.; Biju, S.; Ghosh, B. R.; Sinha, P. P.

    2007-01-01

    Low weld strength of fusion welded joints of aluminium alloy AA2219 is a concern in fabrication of pressure vessels and is attributable to the presence of weld defects, as well as various metallurgical factors. Friction stir welding (FSW), being a solid state joining process has obvious advantages over fusion welding. Results of preliminary FSW experiments conducted on 10 mm thick plate using a particular tool configuration are presented here. Microscopic studies show the presence of very fine equiaxed recrystallised grain at the weld nugget and a flow pattern of grains due to heavy deformation in defect-free weld coupons. Mechanical properties are correlated with the microstructure and process variables. Fractographic analysis complements the observations of optical microscopy and mechanical properties

  16. Development of the electron beam welding of the aluminium alloy 6061-T6 for the Jules Horowitz reactor

    International Nuclear Information System (INIS)

    Leblanc, Y.

    2013-01-01

    The aluminium alloy 6061-T6 has been selected for the construction of the Jules Horowitz's reactor vessel. This reactor vessel is pressurized and will be made through butt welding of ∼ 2 cm thick aluminium slabs. The electron beam welding process has been tested and qualified. It appears that this welding process allows: -) welding without pre-heating, -) vacuum welding, -) welding of 100% of the thickness in one passage, -) very low deforming welding process, -) very low density and very low volume of blow holes, -) weak ZAT (Thermal Affected Zones), and -) high reproducibility that permits automation. (A.C.)

  17. Microstructure strengthening mechanisms in an Al–Mg–Si–Sc–Zr equal channel angular pressed aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Cabibbo, Marcello, E-mail: m.cabibbo@univpm.it [Dipartimento di Ingegneria Meccanica e Scienze Matematiche (DIISM), Università Politecnica delle Marche, 60131 Ancona (Italy)

    2013-09-15

    Microstructure dislocation strengthening mechanisms in severely deformed aluminium strongly depend on the different boundary evolutions. Thereafter, models of proof stress determination should take into account the different nature of the boundaries that form during severe plastic deformation. In the last few decades, Hall–Petch modified relationship and other proof stress modelling were extensively discussed. This paper deals with further insights into the Hansen's and other authors approach to the modelling of aluminium poof stress after equal channel angular pressing. The present model is based on a detailed transmission electron microscopy microstructure characterization of the different strengthening contributions in an age-hardened Al–Mg–Si–Sc–Zr alloy.

  18. Microstructure strengthening mechanisms in an Al–Mg–Si–Sc–Zr equal channel angular pressed aluminium alloy

    International Nuclear Information System (INIS)

    Cabibbo, Marcello

    2013-01-01

    Microstructure dislocation strengthening mechanisms in severely deformed aluminium strongly depend on the different boundary evolutions. Thereafter, models of proof stress determination should take into account the different nature of the boundaries that form during severe plastic deformation. In the last few decades, Hall–Petch modified relationship and other proof stress modelling were extensively discussed. This paper deals with further insights into the Hansen's and other authors approach to the modelling of aluminium poof stress after equal channel angular pressing. The present model is based on a detailed transmission electron microscopy microstructure characterization of the different strengthening contributions in an age-hardened Al–Mg–Si–Sc–Zr alloy.

  19. Fracture mechanisms of aluminium alloy AA7075-T651 under various loading conditions

    International Nuclear Information System (INIS)

    Pedersen, Ketill O.; Borvik, Tore; Hopperstad, Odd Sture

    2011-01-01

    The fracture behaviour of the aluminium alloy AA7075-T651 is investigated for quasi-static and dynamic loading conditions and different stress states. The fracture surfaces obtained in tensile tests on smooth and notched axisymmetric specimens and compression tests on cylindrical specimens are compared to the fracture surfaces that occur when a projectile, having either a blunt or an ogival nose shape, strikes a 20 mm thick plate of the aluminium alloy. The stress state in the impact tests is much more complex and the strain rate significantly higher than in the tensile and compression tests. Optical and scanning electron microscopes are used in the investigation. The fracture surface obtained in tests with smooth axisymmetric specimens indicates that the crack growth is partly intergranular along the grain boundaries or precipitation free zones and partly transgranular by void formation around fine and coarse intermetallic particles. When the stress triaxiality is increased through the introduction of a notch in the tensile specimen, delamination along the grain boundaries in the rolling plane is observed perpendicular to the primary crack. In through-thickness compression tests, the crack propagates within an intense shear band that has orientation about 45 o with respect to the load axis. The primary failure modes of the target plate during impact were adiabatic shear banding when struck by a blunt projectile and ductile hole-enlargement when struck by an ogival projectile. Delamination and fragmentation of the plates occurred for both loading cases, but was stronger for the ogival projectile. The delamination in the rolling plane was attributed to intergranular fracture caused by tensile stresses occurring during the penetration event.

  20. Flow and failure of an aluminium alloy from low to high temperature and strain rate

    Science.gov (United States)

    Sancho, Rafael; Cendón, David; Gálvez, Francisco

    2015-09-01

    The mechanical behaviour of an aluminium alloy is presented in this paper. The study has been carried out to analyse the flow and failure of the aluminium alloy 7075-T73. An experimental study has been planned performing tests of un-notched and notched tensile specimens at low strain rates using a servo-hydraulic machine. High strain rate tests have been carried out using the same geometry in a Hopkinson Split Tensile Bar. The dynamic experiments at low temperature were performed using a cryogenic chamber, and the high temperature ones with a furnace, both incorporated to the Hopkinson bar. Testing temperatures ranged from - 50 ∘C to 100 ∘C and the strain rates from 10-4 s-1 to 600 s-1. The material behaviour was modelled using the Modified Johnson-Cook model and simulated using LS-DYNA. The results show that the Voce type of strain hardening is the most accurate for this material, while the traditional Johnson-Cook is not enough accurate to reproduce the necking of un-notched specimens. The failure criterion was obtained by means of the numerical simulations using the analysis of the stress triaxiality versus the strain to failure. The diameters at the failure time were measured using the images taken with an image camera, and the strain to failure was computed for un-notched and notched specimens. The numerical simulations show that the analysis of the evolution of the stress triaxiality is crucial to achieve accurate results. A material model using the Modified Johnson-Cook for flow and failure is proposed.

  1. Thermal analysis of laser additive manufacturing of aluminium alloys: Experiment and simulation

    Science.gov (United States)

    Bock, Frederic E.; Froend, Martin; Herrnring, Jan; Enz, Josephin; Kashaev, Nikolai; Klusemann, Benjamin

    2018-05-01

    Laser additive manufacturing (LAM) has become increasingly popular in industry in recent decades because it enables exceptional degrees of freedom regarding the structural design of lightweight components compared to subtractive manufacturing techniques. Laser metal deposition (LMD) of wire-fed material shows in particular the advantages such as high process velocity and efficient use of material compared to other LAM processes. During wire-based LMD, the material is deposited onto a substrate and supplemented by successive layers allowing a layer-wise production of complex three-dimensional structures. Despite the increased productivity of LMD, regarding the ability to process aluminium alloys, there is still a lack in quality and reproducibility due to the inhomogeneous temperature distribution during the process, leading to undesired residual stresses, distortions and inconsistent layer geometries and poor microstructures. In this study, the aluminium alloy AA5087 as wire and AA5754 as substrate material were utilized for LMD. In order to obtain information about the temperature field during LMD, thermocouple and thermography measurements were performed during the process. The temperature measurements were used to validate a finite element model regarding the heat distribution, which will be further used to investigate the temperature field evolution over time. To consider the continuous addition of material within the FE-model, an inactive/active element approach was chosen, where initially deactivated elements are activated corresponding to the deposition of material. The first results of the simulation and the experiments show good agreement. Therefore, the model can be used in the future for LMD process optimization, e.g., in terms of minimizing local variations of the thermal load for each layer.

  2. Microstructures in the 6060 aluminium alloy after various severe plastic deformation treatments

    International Nuclear Information System (INIS)

    Adamczyk-Cieslak, Boguslawa; Mizera, Jaroslaw; Kurzydlowski, Krzysztof Jan

    2011-01-01

    This paper presents the results concerning the microstructural refinement of the industrial 6060 aluminium alloy processed by severe plastic deformation (SPD). The high level of plastic deformation was achieved using the three methods: hydrostatic extrusion (HE), equal channel angular extrusion (ECAE) and extrusion torsion (ET), which differed in the dynamics of the loading, intensity and homogeneity of the plastic strain field. Microstructure analyses were performed before and after SPD deformation using a transmission (TEM) and a scanning electron microscope (SEM). The refined microstructures were examined qualitatively and quantitatively by the stereological methods and computer image analyses. The microstructure of the industrial 6060 aluminium alloy after deformation was characterized by an average grain size of about 0.4 μm. The results show that the precipitates strongly affect the degree of refinement and the mechanism of microstructural transformations. During the SPD, the second phase particles break apart and homogenize. The HE method generates the largest increase of the volume fraction of the small primary particles. Moreover, the HE process is most effective in reducing the primary particle size. During HE and ECAE processes the second phase precipitates dissolve partially and change their shape. - Research Highlights: → SPD results in a significant increase in the density of the small primary particles. → SPD homogenizes the particle size distribution. → HE and ECAE processes bring nano-grains in the vicinity of the primary particles. → HE and ECAE processing results in the β' precipitates partial dissolutions. → During HE and ECAE processes the β' particles change their shape.

  3. Influence of the Aluminium Alloy Type on Defects Formation in Friction Stir Lap Welding of Thin Sheets

    Directory of Open Access Journals (Sweden)

    M. I. Costa

    Full Text Available Abstract The weldability in Friction Stir Lap Welding (FSLW of heat and non-heat treatable aluminium alloys, the AA6082-T6 and the AA5754-H22 aluminium alloys, respectively, are compared. For both alloys, welds were produced in very thin sheets, using the same welding parameters and procedures, and strong differences in welds morphology were found. The strength of the welds was evaluated by performing tensile-shear tests under monotonic and cyclic loading conditions. As-welded and heat-treated samples of the AA6082- T6 were tested. It was found that the heat-treatable alloy is more sensitive to defects formation, in lap welding, than the non-heat-treatable alloy. The presence of defects has a strong influence on the monotonic and fatigue behaviour of the welds. In spite of this, for very high-applied stresses, the heat-treatable alloy welds perform better in fatigue than the non-heat-treatable alloy welds.

  4. A survey of some metallographic etching reagents for restoration of obliterated engraved marks on aluminium-silicon alloy surfaces.

    Science.gov (United States)

    Uli, Norjaidi; Kuppuswamy, R; Amran, Mohd Firdaus Che

    2011-05-20

    A brief survey to assess the sensitivity and efficacy of some common etching reagents for revealing obliterated engraved marks on Al-Si alloy surfaces is presented. Experimental observations have recommended use of alternate swabbing of 10% NaOH and 10% HNO(3) on the obliterated surfaces for obtaining the desired results. The NaOH etchant responsible for bringing back the original marks resulted in the deposition of some dark coating that has masked the recovered marks. The coating had been well removed by dissolving it in HNO(3) containing 10-20% acid. However, the above etching procedure was not effective on aluminium (99% purity) and Al-Zn-Mg-Cu alloy surfaces. Also the two reagents (i) immersion in 10% aq. phosphoric acid and (ii) alternate swabbing of 60% HCl and 40% NaOH suggested earlier for high strength Al-Zn-Mg-Cu alloys [23] were quite ineffective on Al-Si alloys. Thus different aluminium alloys needed different etching treatments for successfully restoring the obliterated marks. Al-Si alloys used in casting find wide applications especially in the manufacture of engine blocks of motor vehicles. Hence, the results presented in this paper are of much relevance in serial number restoration problems involving this alloy. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  5. High temperature oxidation of copper and copper aluminium alloys: Impact on furnace side wall cooling systems

    Science.gov (United States)

    Plascencia Barrera, Gabriel

    The high temperature oxidation behaviours of copper and dilute Cu-Al alloys were investigated. Experiments were carried out by: (i) Oxidizing under various oxygen potentials at different temperatures using a combined TG-DTA apparatus. (ii) Oxidizing in a muffle furnace (in air) at different temperatures for extended periods of time. The oxidation mechanisms were evaluated based upon the kinetic data obtained as well as by X-ray diffraction and microscopical (SEM and optical) analyses. It was found that oxidation of copper strongly depends on the temperature. Two distinct mechanisms were encountered. Between 300 and 500°C, the oxidation rate is controlled by lateral growth of the oxide on the metal surface, whereas between 600 and 1000°C oxidation is controlled by lattice diffusion of copper ions through the oxide scale. On the other hand, the partial pressure of oxygen only has a small effect on the oxidation of copper. Alloy oxidation is also dependent on the temperature. As temperature increases, more aluminium is required to protect copper from being oxidized. It was shown that if the amount of oxygen that dissolves in the alloy exceeds the solubility limit of oxygen in copper, an internal oxidation layer will develop, leading to the formation of a tarnishing scale. On the other hand if the oxygen content in the alloy lies below the solubility limit of oxygen in copper, no oxidation products will form since a tight protective alumina layer will form on the alloy surface. Surface phenomena may affect the oxidation behaviour of dilute Cu-Al alloys. Immersion tests in molten copper matte and copper converting slag, using laboratory scale cooling elements with various copper based materials, were conducted. Results from these tests showed that alloying copper with 3 to 4 wt% Al decreases the oxidation rate of pure copper by 4 orders of magnitude; however due to a significant drop in thermal conductivity, the ability to extract heat is compromised, leading to

  6. Fabrication and tribological response of aluminium 6061 hybrid composite reinforced with bamboo char and boron carbide micro-fillers

    Science.gov (United States)

    Chethan, K. N.; Pai, Anand; Keni, Laxmikant G.; Singhal, Ashish; Sinha, Shubham

    2018-02-01

    Metal matrix composites (MMCs) have a wide scope of industrial applications and triumph over conventional materials due to their light weight, higher specific strength, good wear resistance and lower coefficient of thermal expansion. The present study aims at establishing the feasibility of using Bamboo charcoal particulate and boron carbide as reinforcements in Al-6061 alloy matrix and to investigate their effect on the wear of composites taking into consideration the interfacial adhesion of the reinforcements in the alloy. Al-6061 alloy was chosen as a base metallic alloy matrix. Sun-dried bamboo canes were used for charcoal preparation with the aid of a muffle furnace. The carbon content in the charcoal samples was determined by EDS (energy dispersive spectroscopy). In present study, stir casting technique was used to prepare the samples with 1%, 2%, and 3% weight of bamboo charcoal and boron carbide with Al-6061. The fabricated composites were homogenised at 570°C for 6 hours and cooled at room temperature. Wear studies were carried out on the specimens with different speed and loads. It was found that wear rate and coefficient of friction decreased with increase in the reinforcement content.

  7. The influence of quench sensitivity on residual stresses in the aluminium alloys 7010 and 7075

    International Nuclear Information System (INIS)

    Robinson, J.S.; Tanner, D.A.; Truman, C.E.; Paradowska, A.M.; Wimpory, R.C.

    2012-01-01

    The most critical stage in the heat treatment of high strength aluminium alloys is the rapid cooling necessary to form a supersaturated solid solution. A disadvantage of quenching is that the thermal gradients can be sufficient to cause inhomogeneous plastic deformation which in turn leads to the development of large residual stresses. Two 215 mm thick rectilinear forgings have been made from 7000 series alloys with widely different quench sensitivity to determine if solute loss in the form of precipitation during quenching can significantly affect residual stress magnitudes. The forgings were heat treated and immersion quenched using cold water to produce large magnitude residual stresses. The through thickness residual stresses were measured by neutron diffraction and incremental deep hole drilling. The distribution of residual stresses was found to be similar for both alloys varying from highly triaxial and tensile in the interior, to a state of biaxial compression in the surface. The 7010 forging exhibited larger tensile stresses in the interior. The microstructural variation from surface to centre for both forgings was determined using optical and transmission electron microscopy. These observations were used to confirm the origin of the hardness variation measured through the forging thickness. When the microstructural changes were accounted for in the through thickness lattice parameter, the residual stresses in the two forgings were found to be very similar. Solute loss in the 7075 forging appeared to have no significant effect on the residual stress magnitudes when compared to 7010. - Highlights: ► Through thickness residual stress measurements made on large Al alloy forgings. ► Residual stress characterised using neutron diffraction and deep hole drilling. ► Biaxial compressive surface and triaxial subsurface residual stresses. ► Quench sensitivity of 7075 promotes significant microstructural differences to 7010. ► When precipitation is

  8. Rheological Analysis of Semi-Solid A380.0 Aluminium Alloy / Analiza Właściwości Reologicznych Stopu Aluminium A380.0 W Stanie Stało-Ciekłym

    Directory of Open Access Journals (Sweden)

    Solek K.

    2015-12-01

    Full Text Available Knowledge of the rheological properties is crucial for the numerical modeling of technological processes. The main objective of this study was to conduct an analysis of the rheological properties of A380.0 (AlSi9Cu3(Fe aluminium alloy in the semi-solid state. The results could be used for identification of temperature range of the alloy, where thixoforming processes could be executed. Another purpose of the experimental work could be development of the mathematical models of the alloy apparent viscosity. The significant achievement of this particular study is an application of a viscometer which was specially designed for material tests executed at high temperatures, such as the measurement of liquid or semi-liquid aluminium viscosity. This paper presents the results of a rheological analysis of aluminium alloy.

  9. Effect of mechanical alloying on FeCrC reinforced Ni alloys

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, S. Osman [Univ. of Namik Kemal, Tekirdag (Turkey); Teker, Tanju [Adiyaman Univ. (Turkey). Dept. of Metallurgical and Materials Engineering; Demir, Fatih [Batman Univ. (Turkey)

    2016-05-01

    Mechanical alloying (MA) is a powder metallurgy processing technique involving cold welding, fracturing and rewelding of powder particles in a high-energy ball mill. In the present study, the intermetallic matrix composites (IMCs) of Ni-Al reinforced by M{sub 7}C{sub 3} were produced by powder metallurgical routes via solid state reaction of Ni, Al and M{sub 7}C{sub 3} particulates by mechanical alloying processes. Ni, Al and M{sub 7}C{sub 3} powders having 100 μm were mixed, mechanical alloyed and the compacts were combusted in a furnace. The mechanically alloyed (MAed) powders were investigated by X-ray diffraction (XRD), microhardness measurement, optic microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The presence of the carbides depressed the formation of unwanted NiAl intermetallic phases. The mechanical alloyed M{sub 7}C{sub 3} particles were unstable and decomposed partially within the matrix during alloying and sintering, and the morphology of the composites changed with the dissolution ratio of M{sub 7}C{sub 3} and sintering temperature.

  10. Microstructure and high temperature stability of age hardenable AA2219 aluminium alloy modified by Sc, Mg and Zr additions

    Energy Technology Data Exchange (ETDEWEB)

    Naga Raju, P. [Metallurgical and Materials Engineering Department, IIT-Madras, Chennai 600036 (India)], E-mail: puvvala_nagaraju@yahoo.com; Srinivasa Rao, K. [Metallurgical Engineering Department, Andhra University, Visakapatnam 530003 (India); Reddy, G.M. [Defence Metallurgical Research Laboratory, Hyderabad 500258 (India); Kamaraj, M.; Prasad Rao, K. [Metallurgical and Materials Engineering Department, IIT-Madras, Chennai 600036 (India)

    2007-08-25

    The present work pertains to the improvement of high temperature stability of age hardenable AA2219 aluminium-copper (6.3%) alloy. Addition of scandium, magnesium and zirconium to the base metal AA2219 was adopted to improve this high temperature stability. These additions were systematically varied by preparing alloys of different composition using gas tungsten arc melting. Long time ageing studies and impression creep technique were used to study the high temperature stability of the alloys. These modified compositions of the alloy resulted in fine equiaxed grains, refined eutectics, large number of high temperature stable and finer precipitates. Among all the compositions, 0.8% Sc + 0.45% Mg + 0.2% Zr addition was found to be significant in improving the high temperature stability of AA2219 alloy. This may be attributed to the possible microstructural changes, solute enrichment of the matrix and pinning of the grain boundaries by the finer precipitates.

  11. Mechanical behaviour of aluminium matrix composites with particles in high temperature

    International Nuclear Information System (INIS)

    Amigo, V.; Salvador, M. D.; Ferrer, C.; Costa d, C. E.; Busquets, D.

    2001-01-01

    The aluminium matrix composites materials reinforced by ceramic particles can be elaborated by powder metallurgy techniques, with extrusion processes. These can provide new materials, with a better mechanical behaviour and moreover when we need those properties at higher temperatures. Aluminium alloy reinforced composites with silicon nitride particles by powder extrusion process was done. Their mechanical properties were characterised at room and elevated temperatures. (Author) 28 refs

  12. Oxide growth on aluminium alloys in the presence of ammonium fluoborate

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, J.; Paterson, P.; Flavell, T. [Royal Melbourne Inst. of Tech., VIC (Australia); Biddle, G. [Alcoa Rolled Products (Australia)

    1996-12-31

    The aim of this study as to determine the mechanisms involved in using ammonium fluoborate as a reducing atmosphere when preheating a high magnesium content aluminium alloy. Rutherford Backscattering (RBS) has been the major technique used in the analysis of samples, it revealed significant reduction in both the diffusion of magnesium to the surface and the calculated oxide thickness in the presence of NH{sub 4}BF{sub 4}. At temperatures above 500 deg C in air, SEM images revealed depressions and voids due to incipient melting at various stages, around the grain boundaries. Grain boundaries effectively acted as pipes aiding the diffusion of magnesium to the surface. These results have been verified through compositional analysis with both RBS and auger electron spectroscopy (AES). Results from NH{sub 4}BF{sub 4} atmosphere preheat conditions showed significant improvements. It was verified experimentally that above 500 deg C , AA5182 alloys undergo incipient melting at the grain boundaries with magnesium diffusing through to the surface. 5 refs., 1 fig.

  13. Effects of vacuum and ageing on Zr4/Cr3 based conversion coatings on aluminium alloys

    Science.gov (United States)

    Thirupathi, Kalaivanan; Bárczy, Pál; Vad, Kálmán; Csik, Attila; Somosvári, Béla Márton

    2018-05-01

    In this study, we investigate the impact of ageing and high vacuum on existing environmentally friendly Zr4/Cr3-based conversion coatings. The freshly formed coating undergoes several changes during ageing and exposure to high vacuum. Based on the present data, we propose that the coating formed over AA6082 and AA7075 alloys is sol-gel in nature, confirmed by secondary neutral mass spectroscopy (SNMS) using the depth profiling technique. Our findings reveal that there are elemental level changes that result in shrinkage of the coating. Most Zr ions in the coating are in the solute form, with lesser number of Cr and Al ions that disappear under high vacuum over a certain period of time. The remaining Cr, Zr and O atoms exist in a gelatinous state. During ageing, there is a continuous transition of ions from solute to gelatinous state. In addition, the deposition of coating ions is directly influenced by the substrates and their constituents. The extent of dissolution of aluminium in the conversion bath determines both Zr and Cr ion deposition. For a highly alloyed metal like AA7075, the dissolution rate is disturbed by copper and zinc.

  14. Distribution of trace elements in a modified and grain refined aluminium-silicon hypoeutectic alloy.

    Science.gov (United States)

    Faraji, M; Katgerman, L

    2010-08-01

    The influence of modifier and grain refiner on the nucleation process of a commercial hypoeutectic Al-Si foundry alloy (A356) was investigated using optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis technique (EPMA). Filtering was used to improve the casting quality; however, it compromised the modification of silicon. Effect of filtering on strontium loss was also studied using the afore-mentioned techniques. EPMA was used to trace the modifying and grain refining agents inside matrix and eutectic Si. This was to help understanding mechanisms of nucleation and modification in this alloy. Using EPMA, the negative interaction of Sr and Al3TiB was closely examined. In modified structure, it was found that the maximum point of Sr concentration was in line with peak of silicon; however, in case of just 0.1wt% added Ti, the peak of Ti concentration was not in line with aluminium, (but it was close to Si peak). Furthermore, EPMA results showed that using filter during casting process lowered the strontium content, although produced a cleaner melt. (c) 2010 Elsevier Ltd. All rights reserved.

  15. Constitutive modelling of creep-ageing behaviour of peak-aged aluminium alloy 7050

    Directory of Open Access Journals (Sweden)

    Yang Yo-Lun

    2015-01-01

    Full Text Available The creep-ageing behaviour of a peak-aged aluminium alloy 7050 was investigated under different stress levels at 174 ∘C for up to 8 h. Interrupted creep tests and tensile tests were performed to investigate the influences of creep-ageing time and applied stress on yield strength. The mechanical testing results indicate that the material exhibits an over-ageing behaviour which increases with the applied stress level during creep-ageing. As creep-ageing time approaches 8 h, the material's yield strength under different stress levels gradually converge, which suggests that the difference in mechanical properties under different stress conditions can be minimised. This feature can be advantageous in creep-age forming to the formed components such that uniformed mechanical properties across part area can be achieved. A set of constitutive equations was calibrated using the mechanical test results and the alloy-specific material constants were obtained. A good agreement is observed between the experimental and calibrated results.

  16. Study of microstructural evolutions of the 6061-T6 aluminium alloy under irradiation

    International Nuclear Information System (INIS)

    Flament, Camille

    2015-01-01

    The 6061-T6 Aluminium alloy, whose microstructure contains Al(Fe,Mn,Cr)Si dispersoids and hardening needle-shaped β'' precipitates (Mg, Si), has been chosen as the structural material for the core vessel of the Material Testing Jules Horowitz Nuclear Reactor. Because it will be submitted to high neutron flux at a temperature around 50 C, it is necessary to study microstructural evolutions induced by irradiation and especially the stability of the second phase particles. In this work, an analytical study by in-situ and ex-situ electron and ion irradiations has been performed, as well as a study under neutron irradiation. The precipitate characterization by Transmission Electron Microscopy demonstrates that Al(Fe,Mn,Cr)Si dispersoids are driven under irradiation towards their equilibrium configuration, consisting of a core/shell structure, enhanced by irradiation, with a (Fe, Mn) enriched core surrounded by a Cr-enriched shell. In contrast, the (Mg,Si) β'' precipitates are destabilized by irradiation. They dissolve under ion irradiation in favor of a new precipitation of (Mg,Si,Cu,Cr,Al) rich clusters resulting in an increase of the alloy's hardness. β'' precipitates tend towards a transformation to cubic precipitates under neutron irradiation. (author) [fr

  17. Oxide growth on aluminium alloys in the presence of ammonium fluoborate

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, J; Paterson, P; Flavell, T [Royal Melbourne Inst. of Tech., VIC (Australia); Biddle, G [Alcoa Rolled Products (Australia)

    1997-12-31

    The aim of this study as to determine the mechanisms involved in using ammonium fluoborate as a reducing atmosphere when preheating a high magnesium content aluminium alloy. Rutherford Backscattering (RBS) has been the major technique used in the analysis of samples, it revealed significant reduction in both the diffusion of magnesium to the surface and the calculated oxide thickness in the presence of NH{sub 4}BF{sub 4}. At temperatures above 500 deg C in air, SEM images revealed depressions and voids due to incipient melting at various stages, around the grain boundaries. Grain boundaries effectively acted as pipes aiding the diffusion of magnesium to the surface. These results have been verified through compositional analysis with both RBS and auger electron spectroscopy (AES). Results from NH{sub 4}BF{sub 4} atmosphere preheat conditions showed significant improvements. It was verified experimentally that above 500 deg C , AA5182 alloys undergo incipient melting at the grain boundaries with magnesium diffusing through to the surface. 5 refs., 1 fig.

  18. Oxide growth on aluminium alloys in the presence of ammonium fluoborate

    International Nuclear Information System (INIS)

    Oliver, J.; Paterson, P.; Flavell, T.; Biddle, G.

    1996-01-01

    The aim of this study as to determine the mechanisms involved in using ammonium fluoborate as a reducing atmosphere when preheating a high magnesium content aluminium alloy. Rutherford Backscattering (RBS) has been the major technique used in the analysis of samples, it revealed significant reduction in both the diffusion of magnesium to the surface and the calculated oxide thickness in the presence of NH 4 BF 4 . At temperatures above 500 deg C in air, SEM images revealed depressions and voids due to incipient melting at various stages, around the grain boundaries. Grain boundaries effectively acted as pipes aiding the diffusion of magnesium to the surface. These results have been verified through compositional analysis with both RBS and auger electron spectroscopy (AES). Results from NH 4 BF 4 atmosphere preheat conditions showed significant improvements. It was verified experimentally that above 500 deg C , AA5182 alloys undergo incipient melting at the grain boundaries with magnesium diffusing through to the surface. 5 refs., 1 fig

  19. Neutron and synchrotron measurements of residual strain in TIG welded aluminium alloy 2024

    International Nuclear Information System (INIS)

    Owen, R.A.; Preston, R.V.; Withers, P.J.; Shercliff, H.R.; Webster, P.J.

    2003-01-01

    Tungsten inert gas (TIG) welding is one method of joining aluminium alloys with potential application in the aerospace industry. However, for it to be seriously considered as an alternative to mechanical fasteners the interrelated problems of residual stress and distortion need to be addressed. In this paper neutron, laboratory and synchrotron X-ray diffraction methods are used to provide non-destructive information about the residual stress field in TIG-welded 2024 Al alloy. The results compare well despite the differing penetration and sampling volumes associated with each technique. It is found that the magnitudes of the tensile longitudinal stresses decrease along the plate due to progressive heating up of the plate ahead of the arc during welding, so that steady-state conditions are not achieved. Comparison of the data with a finite element model indicates that softening of the heat-affected region must be included to simulate the resulting stress field. The FE model is found to be in good agreement with the data especially in the vicinity of the weld slope-out

  20. Oxidation of an aluminium-magnesium alloy in liquid state. Methodology of determination of mechanisms from not necessarily repeatable experiments

    International Nuclear Information System (INIS)

    Surla, Karine

    1998-01-01

    This research thesis reports the study of the oxidation of an aluminium-5 pc magnesium alloy in its liquid state in an oxygen environment, using thermogravimetric analysis and that of magnesium in its solid state. In a first part, the author reports a thermodynamic and bibliographical study on magnesium transformation in its solid state (Mg/O 2 and Mg/H 2 O systems, transformation with dry and humid synthetic air, oxidation inhibitors) and on Al-Mg alloy transformation in presence of oxygen (thermodynamic properties of aluminium-rich Al-Mg alloys, Al-Mg/O 2 /N 2 and Al-Mg/O 2 /N 2 /H 2 O systems). The next parts address the selection of reaction systems for the different cases (oxidation of solid magnesium in oxygen, oxidation of the Al-Mg alloy in oxygen), the modelling of the formation of magnesia from solid magnesium and from the Al-Mg alloy, and the modelling of the liquid Al-Mg A5182 alloy oxidation in oxygen [fr

  1. Aluminium and copper analysis in metallic alloys by neutron activation analysis from an 241 Am-Be source

    International Nuclear Information System (INIS)

    Carvalho, J. de.

    1980-01-01

    Aluminium and copper have been determined in aluminium alloys by the method of activation with neutrons from an 241 Am-Be source of intensity 9,8 x 10 6 n/s. The activity induced due to reactions 27 Al (n, γ) 28 Al and 63 Cu (n, γ) 64 Cu have been measured with a NaI (Tl) detector coupled to a single channel system. In order to obtain the samples and standards of about the same composition, the material to be irradiated was powdered. In view of low intensity of neutron source it was necessary to use samples of up to 50 g. A series of preliminary irradiations were carried out to ensure that the geometry for the irradiation and for the counting are reproducible. The results have been compared with those obtained by chemical methods. Assuming that the results obtained by chemical method is exact, a maximum relative error of 3,6% is obtained by this method. The method has a good reproducibility. The time needed for analysis of aluminium and copper are 18 min and 2 hours 40 minutes respectively. Four different samples were analysed. The average of five measurements for one of the samples was: 88.0% for aluminium and 10.0% for copper. The standard deviation and coefficient of variation were 0,8 and 1.0% for aluminium and 0,2 and 2.0% for copper. (author)

  2. Application of ceramic short fiber reinforced Al alloy matrix composite on piston for internal combustion engines

    Directory of Open Access Journals (Sweden)

    Wu Shenqing

    2010-11-01

    Full Text Available The preparation and properties of ceramic short fiber reinforced Al-Si alloy matrix composite and it’s application on the piston for internal combustion engines are presented. Alumina or aluminosilicate fibers reinforced Al-Si alloy matrix composite has more excellent synthetical properties at elevated temperature than the matrix alloys. A partially reinforced Al-Si alloy matrix composite piston produced by squeeze casting technique has a firm interface between reinforced and unreinforced areas, low reject rate and good technical tolerance. As a new kind of piston material, it has been used for mass production of about 400,000 pieces of automobile engines piston. China has become one of a few countries in which aluminum alloy matrix composite materials have been used in automobile industry and attained industrialization.

  3. Experimental and numerical investigation on under-water friction stir welding of armour grade AA2519-T87 aluminium alloy

    OpenAIRE

    Sree Sabari, S.; Malarvizhi, S.; Balasubramanian, V.; Madusudhan Reddy, G.

    2016-01-01

    Friction stir welding (FSW) is a promising welding process that can join age hardenable aluminium alloys with high joint efficiency. However, the thermal cycles experienced by the material to be joined during FSW resulted in the deterioration of mechanical properties due to the coarsening and dissolution of strengthening precipitates in the thermo-mechanical affected zone (TMAZ) and heat affected zone (HAZ). Under water friction stir welding (UWFSW) is a variant of FSW process which can maint...

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

    Directory of Open Access Journals (Sweden)

    A. Saoudi

    2010-01-01

    Full Text Available 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 the material mesh elements; It also reduces programming costs. We model an aluminium alloy lower vehicle suspension arm under real conditions. The natural frequencies of the part are inversely proportional to the mass and proportional to flexural stiffness, and assumed to be invariable during the process of optimization. The objective function developed in this study is linked directly to the notion of fatigue. The method identifies elements that have less than 10% of the fatigue life of the part's critical element. We achieved a weight loss of 5 to 11% by removing the identified elements following the first iteration.

  5. Weldability of AA 5052 H32 aluminium alloy by TIG welding and FSW process - A comparative study

    Science.gov (United States)

    Shanavas, S.; Raja Dhas, J. Edwin

    2017-10-01

    Aluminium 5xxx series alloys are the strongest non-heat treatable aluminium alloy. Its application found in automotive components and body structures due to its good formability, good strength, high corrosion resistance, and weight savings. In the present work, the influence of Tungsten Inert Gas (TIG) welding parameters on the quality of weld on AA 5052 H32 aluminium alloy plates were analyzed and the mechanical characterization of the joint so produced was compared with Friction stir (FS) welded joint. The selected input variable parameters are welding current and inert gas flow rate. Other parameters such as welding speed and arc voltage were kept constant throughout the study, based on the response from several trial runs conducted. The quality of the weld is measured in terms of ultimate tensile strength. A double side V-butt joints were fabricated by double pass on one side to ensure maximum strength of TIG welded joints. Macro and microstructural examination were conducted for both welding process.

  6. Study of the uniform corrosion of an aluminium alloy used for the fuel cladding of the Jules Horowitz experimental reactor

    International Nuclear Information System (INIS)

    Wintergerst, M.

    2008-01-01

    For the Jules Horowitz new material testing reactor, an aluminium base alloy, AlFeNi, will be used for the cladding of the fuel plates. Taking into account the thermal properties of the alloy and of its oxide, the corrosion of the fuel cans presents many problems. The aim of this thesis is to provide a growing kinetic of the oxide layer at the surface of the AlFeNi fuel can in order to predict the life time of fuel element. Thus the mechanism of degradation of the cladding will be describe in order to integrate the different parameters of the operating reactor. (A.L.B.)

  7. Circular economy: To be or not to be in a closed product loop? A Life Cycle Assessment of aluminium cans with inclusion of alloying elements

    DEFF Research Database (Denmark)

    Niero, Monia; Olsen, Stig Irving

    2016-01-01

    Packaging, representing the second largest source of aluminium scrap at global level, deserves a key role in the transition towards the circular economy. Life Cycle Assessment (LCA) of aluminium products has been typically based on one life cycle considering pure aluminium flows and neglecting...... the presence of alloying elements and impurities. However, this simplification undermines the potentials of using LCA to quantify the environmental performances of products in multiple loops, as required in the circular economy. This study aims to investigate the effects of including the actual alloy...... composition in the LCA of aluminium can production and recycling, in order to understand whether a can-to-can (i.e. closed product loop) recycling should be promoted or not. Mass balance of the main alloying elements (Mn, Si, Cu, Fe) was carried out at increasing levels of recycling rate, corresponding...

  8. Fabrication and characterization of aluminium hybrid composites reinforced with fly ash and silicon carbide through powder metallurgy

    Science.gov (United States)

    Bilal Naim Shaikh, Mohd; Arif, Sajjad; Arif Siddiqui, M.

    2018-04-01

    This paper reports the fabrication and characterization of aluminium hybrid composites (AMCs) reinforced with commonly available and inexpensive fly ash (FA, 0, 5, 10 and 15 wt.%) particles along silicon carbide (SiC) using powder metallurgy process. Scanning electron microscopy (SEM) and x-ray diffraction (XRD) were employed for microstructural characterization and phase identification respectively. Wear behaviour were investigated using pin-on-disc wear tester for the different combinations of wear parameters like load (10, 20 and 30 N), sliding speed (1.5, 2 and 2.5 m s‑1) and sliding distance (300, 600 and 900 m). SEM confirms the uniform distribution of FA and SiC in aluminium matrix. The hardness of Al/SiC/FA is increased by 20%–25% while wear rate decreased by 15%–40%. From wear analysis, sliding distance was the least significant parameter influencing the wear loss followed by applied load and sliding speed. To identify the mechanism of wear, worn out surface were also analysed by SEM.

  9. Stainless steel fibre reinforced aluminium matrix composites processed by squeeze casting: relationship between processing conditions and interfacial microstructure

    International Nuclear Information System (INIS)

    Colin, C.; Marchal, Y.; Boland, F.; Delannay, F.

    1993-01-01

    This work investigates the influence of some processing parameters on the extent of interfacial reaction in squeeze cast aluminium matrix composites reinforced with 12 μm diameter, continuous stainless steel fibres. The average thickness of the reaction layer at fibre/matrix interfaces was measured by image analysis. When casting was made in a die at room temperature, the thickness of the reaction layer was affected on a distance of several mm from the lateral surface or from the bottom of the preform. The results indicate that the major part of the reaction occurs before solidification of the liquid metal. The control of the extent of interfacial reaction can be achieved through optimization of both infiltration parameters and features of the preform such as the volume fraction of the fibres. (orig.)

  10. Study of Dissimilar Welding AA6061 Aluminium Alloy and AZ31B Magnesium Alloy with ER5356 Filler Using Friction Stir Welding

    Science.gov (United States)

    Mahamud, M. I. I.; Ishak, M.; Halil, A. M.

    2017-09-01

    This paper is to study of dissimilar welding AA6061 aluminium alloy and AZ31B magnesium alloy with ER5356 filler using friction stir welding. 2 mm thick plates of aluminium and magnesium were used. Friction stir welding operations were performed at different rotation and travel speeds and used the fixed tilt angle which is 3°. The rotation speeds varied from 800 to 1100 rpm, and the travel speed varied from 80 to 100 mm/min. In the range rotation speed of 800 to 1000 rpm and welding speed of 80 to 100 mm/min there are no defect at the weld. Tensile test show the higher tensile strength is 198 MPa and the welding efficiency is about 76%.

  11. Diffusion bonding of transition structures for integral aluminium-fibre reinforced polymer (FRP) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Hehl, A. von [IWT - Stiftung Institut fuer Werkstofftechnik, Hauptabteilung Werkstofftechnik, Bremen (Germany); Syassen, F. [Airbus Operations GmbH, Metal Technology, Bremen (Germany); Schimanski, K.

    2012-04-15

    Components in hybrid design become more and more important in terms of their lightweight potential. In this context the demand for weight saving in aerospace leads to increasing numbers of applications of fibre composites for primary structural components. In consequence the use of FRP-metal compounds is necessary. Within the investigations of the researcher group ''Schwarz Silber'' (FOR 1224) founded by the DFG (German Research Foundation) material optimised interface structures for advanced CFRP-aluminium compounds are currently being studied. Within their work the researcher group focussed on three concepts realizing the transition structures: the usage of wires (titanium), foils (titanium) and fibres (glass fibre) as transition elements between CFRP and aluminium. For the connection of the aluminium sheet and the transition element die-casting and laser beam welding are basically used. As a possible alternative to the both liquid phase processes a feasibility study haven been done focussing the solid state processes diffusion bonding. The experimental results show the high potential of this process in view of the transferable loads for integral transition structures. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Boron carbide reinforced aluminium matrix composite: Physical, mechanical characterization and mathematical modelling

    International Nuclear Information System (INIS)

    Shirvanimoghaddam, K.; Khayyam, H.; Abdizadeh, H.; Karbalaei Akbari, M.; Pakseresht, A.H.; Ghasali, E.; Naebe, M.

    2016-01-01

    This paper investigates the manufacturing of aluminium–boron carbide composites using the stir casting method. Mechanical and physical properties tests to obtain hardness, ultimate tensile strength (UTS) and density are performed after solidification of specimens. The results show that hardness and tensile strength of aluminium based composite are higher than monolithic metal. Increasing the volume fraction of B_4C, enhances the tensile strength and hardness of the composite; however over-loading of B_4C caused particle agglomeration, rejection from molten metal and migration to slag. This phenomenon decreases the tensile strength and hardness of the aluminium based composite samples cast at 800 °C. For Al-15 vol% B_4C samples, the ultimate tensile strength and Vickers hardness of the samples that were cast at 1000 °C, are the highest among all composites. To predict the mechanical properties of aluminium matrix composites, two key prediction modelling methods including Neural Network learned by Levenberg–Marquardt Algorithm (NN-LMA) and Thin Plate Spline (TPS) models are constructed based on experimental data. Although the results revealed that both mathematical models of mechanical properties of Al–B_4C are reliable with a high level of accuracy, the TPS models predict the hardness and tensile strength values with less error compared to NN-LMA models.

  13. Effects of surface treatment of aluminium alloy 1050 on the adhesion and anticorrosion properties of the epoxy coating

    Energy Technology Data Exchange (ETDEWEB)

    Sharifi Golru, S., E-mail: samanesharifi@aut.ac.ir [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, P.O. Box 15875-4413 Tehran (Iran, Islamic Republic of); Attar, M.M., E-mail: attar@aut.ac.ir [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, P.O. Box 15875-4413 Tehran (Iran, Islamic Republic of); Ramezanzadeh, B. [Department of Surface Coating and Corrosion, Institute for Color Science and Technology, No. 59,Vafamanesh St, Hosainabad Sq, Lavizan, Tehran (Iran, Islamic Republic of)

    2015-08-01

    Highlights: • Aluminium alloy 1050 was treated by zirconium-based (Zr) conversion coating. • The surface morphology and surface free energy of the samples were obtained. • The adhesion properties of the epoxy coating was studied on the treated samples. • The corrosion resistance of the epoxy coating was enhanced on treated samples. - Abstract: The objective of this work is to investigate the effects of zirconium-based (Zr) conversion coating on the adhesion properties and corrosion resistance of an epoxy/polyamide coating applied on the aluminium alloy 1050 (AA1050). Field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectrum (EDS), atomic force microscope (AFM) and contact angle measuring device were employed in order to characterize the surface characteristics of the Zr treated AA1050 samples. The epoxy/polyamide coating was applied on the untreated and Zr treated samples. The epoxy coating adhesion to the aluminium substrate was evaluated by pull-off test before and after 30 days immersion in 3.5% w/w NaCl solution. In addition, the electrochemical impedance spectroscopy (EIS) and salt spray tests were employed to characterize the corrosion protection properties of the epoxy coating applied on the AA1050 samples. Results revealed that the surface treatment of AA1050 by zirconium conversion coating resulted in the increase of surface free energy and surface roughness. The dry and recovery (adhesion strength after 30 days immersion in the 3.5 wt% NaCl solution) adhesion strengths of the coatings applied on the Zr treated aluminium samples were greater than untreated sample. In addition, the adhesion loss of the coating applied on the Zr treated aluminium substrate was lower than other samples. Also, the results obtained from EIS and salt spray test clearly revealed that the Zr conversion coating could enhance the corrosion protective performance of the epoxy coating significantly.

  14. Contribution to the grain refinement of hypoeutectic aluminium-silicon casting alloys: application of a new grain refiner and experience from practice; Beitrag zur Kornfeinung von untereutektischen Aluminium-Silicium-Gusslegierungen: Anwendung eines neuen Kornfeiners und Erfahrungen aus der Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Koch, H. [Aluminium Rheinfelden GmbH, Rheinfelden (Germany)

    2000-10-01

    This paper describes the application of a master alloy on the basis of aluminium-titanium-boron, that is designed for hypoeutectic aluminium-silicon casting alloys. The efficiency of the grain refiner was measured using thermal analysis and sand and permanent mould casted samples. The grain size was measured using metallographic technique. In addition, casting trials using a spiral sand mould were carried out to estimate the influence on the flowing behaviour of the melt. To compare the results, a standard AlTi5B1 rod was used under the same test conditions. Finally, results from practice are shown. The grain refinement mechanism is discussed. (orig.)

  15. Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content; Proprietes elastiques et plastiques des alliages fer-aluminium. Problemes particuliers poses par la fragilite des alliages a forte teneur en aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Mouturat, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-06-01

    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) [French] Cette etude comporte les resultats obtenus avec des alliages fer-aluminium dont la composition s'etend de 0 a pres de 50 atomes pour cent d'aluminium. Nous avons etudie successivement les conditions d'elaboration et de transformation, le module elastique et la limite elastique; un dernier chapitre est consacre a l'etude du phenomene Portevin-le-Chatelier dans les alliages a 40 atomes pour cent d'aluminium. I) La principale difficulte a resoudre residait dans la fragilite intergranulaire des alliages ordonnes; celle-ci a ete

  16. Elastic and plastic properties of iron-aluminium alloys. Special problems raised by the brittleness of alloys of high aluminium content; Proprietes elastiques et plastiques des alliages fer-aluminium. Problemes particuliers poses par la fragilite des alliages a forte teneur en aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Mouturat, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-06-01

    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) [French] Cette etude comporte les resultats obtenus avec des alliages fer-aluminium dont la composition s'etend de 0 a pres de 50 atomes pour cent d'aluminium. Nous avons etudie successivement les conditions d'elaboration et de transformation, le module elastique et la limite elastique; un dernier chapitre est consacre a l'etude du phenomene Portevin-le-Chatelier dans les alliages a 40 atomes pour cent d'aluminium. I) La principale difficulte a resoudre residait dans la fragilite intergranulaire des alliages ordonnes; celle-ci a ete considerablement reduite par des conditions

  17. The effect of natural pre-ageing on the mechanical properties of Rheo-High pressure die cast aluminium alloy 2139

    CSIR Research Space (South Africa)

    Chauke, L

    2015-07-01

    Full Text Available -high pressure die casting process (R-HPDC). Alloy 2139 is a Ag-containing aluminium alloy from the Al-Cu-Mg 2xxx series family. The addition of Ag enhances the age hardening response through the formation of co-clusters that act as precursors to the formation...

  18. Ductile damage in aluminium alloy thin sheets: Correlation between micro-tomography observations and mechanical modeling

    International Nuclear Information System (INIS)

    Thuillier, S.; Maire, E.; Brunet, M.

    2012-01-01

    This work deals with the characterization of ductile damage in an aluminium alloy AA6016-T4 by X-ray micro-tomography, as a function of anisotropy and triaxiality. Interrupted tensile tests on notched samples with three different geometries were performed and the void volume fraction was measured for different strain values, up to rupture. It was shown that void volume fraction evolution with the strain is rather similar at 0° and 90° to RD but at 45° to RD it shows a more rapid evolution. Moreover, for the same strain level, a higher void volume fraction was recorded for a higher triaxiality ratio. Whatever the orientation and the stress triaxiality ratio, void volume fraction values range from 5×10 −4 up to 0.04. A numerical model based on Gurson–Tvergaard–Needleman constitutive equations was used to simulate the different tests. Hardening of the material was identified from macroscopic tensile test nucleation material parameters were identified by a direct method from void volume fraction evolution. It can be seen that the influence of triaxiality on void volume fraction is underestimated, though void growth is nicely predicted for the highest triaxiality ratio, for strains below 0.5. The load level was correctly predicted, except for high strain, where coalescence seems necessary to be taken into account.

  19. Strain Measurement in Aluminium Alloy during the Solidification Process Using Embedded Fibre Bragg Gratings.

    Science.gov (United States)

    Weraneck, Klaus; Heilmeier, Florian; Lindner, Markus; Graf, Moritz; Jakobi, Martin; Volk, Wolfram; Roths, Johannes; Koch, Alexander W

    2016-11-04

    In recent years, the observation of the behaviour of components during the production process and over their life cycle is of increasing importance. Structural health monitoring, for example of carbon composites, is state-of-the-art research. The usage of Fibre Bragg Gratings (FBGs) in this field is of major advantage. Another possible area of application is in foundries. The internal state of melts during the solidification process is of particular interest. By using embedded FBGs, temperature and stress can be monitored during the process. In this work, FBGs were embedded in aluminium alloys in order to observe the occurring strain. Two different FBG positions were chosen in the mould in order to compare its dependence. It was shown that FBGs can withstand the solidification process, although a compression in the range of one percent was measured, which is in agreement with the literature value. Furthermore, different lengths of the gratings were applied, and it was shown that shorter gratings result in more accurate measurements. The obtained results prove that FBGs are applicable as sensors for temperatures up to 740 °C.

  20. Effect of friction stir lap welding conditions on joint strength of aluminium alloy 6060

    International Nuclear Information System (INIS)

    Yazdanian, S; Chen, Z W

    2009-01-01

    Strength of lap joints made by friction stir welding (FSW) depends strongly on how material flows forming the weld nugget zone during FSW and also on how the joint is loaded during testing. Understanding of this processing-property relationship is currently inadequate. In this study, the effects of pin length, welding speed and rotation rate on weld strength using aluminium alloy 6060 were investigated. It has been found that the pin length needed to be slightly greater than the thickness of the sheet for an adequate joint to be established. However, further increase in pin length did not benefit the joint strength. The major factor affecting joint strength has been found to be the rotation speed. An increase in rotation speed resulted in lowering the joint strength. Various modes of fracture have been observed and these modes relate to the degree of hooking and softening. Explanation of how the speed values relate to heat input and material flow and then to the joint strength is given.

  1. Modelling Dynamic Behaviour and Spall Failure of Aluminium Alloy AA7010

    Science.gov (United States)

    Ma'at, N.; Nor, M. K. Mohd; Ismail, A. E.; Kamarudin, K. A.; Jamian, S.; Ibrahim, M. N.; Awang, M. K.

    2017-10-01

    A finite strain constitutive model to predict the dynamic deformation behaviour of Aluminium Alloy 7010 including shockwaves and spall failure is developed in this work. The important feature of this newly hyperelastic-plastic constitutive formulation is a new Mandel stress tensor formulated using new generalized orthotropic pressure. This tensor is combined with a shock equation of state (EOS) and Grady spall failure. The Hill’s yield criterion is adopted to characterize plastic orthotropy by means of the evolving structural tensors that is defined in the isoclinic configuration. This material model was developed and integration into elastic and plastic parts. The elastic anisotropy is taken into account through the newly stress tensor decomposition of a generalized orthotropic pressure. Plastic anisotropy is considered through yield surface and an isotropic hardening defined in a unique alignment of deviatoric plane within the stress space. To test its ability to describe shockwave propagation and spall failure, the new material model was implemented into the LLNL-DYNA3D code of UTHM’s. The capability of this newly constitutive model were compared against published experimental data of Plate Impact Test at 234m/s, 450m/s and 895m/s impact velocities. A good agreement is obtained between experimental and simulation in each test.

  2. Natural aging behaviour of friction stir welded 6005A-T6 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Peng; Sun, Daqian; Li, Hongmei, E-mail: lihongmei@jlu.edu.cn

    2013-08-01

    By local thermal cycles and hardness measurements, supported by transmission electron microscopy, the post-weld natural aging behaviour of friction stir welded 6005A-T6 aluminium alloy was investigated. The results show that the softening in the nugget zone and thermo-mechanically affected zone immediately after welding is mainly caused by the high peak temperatures and rapid cooling rates, resulting in the original β″ precipitates dissolving and restraining re-precipitation. On the one hand, the hardness recovery in both microstructural zones during post-weld natural aging is attributed to the formation of clusters or GP zones depending on the natural aging time. On the other hand, the softening in the heat-affected zone after welding is due to the transformation of the β′′ to β′ precipitates and the precipitation of Q′. Natural aging has little effect on the microstructure and hardness of the heat-affected zone. The mechanism of natural aging behaviour was discussed.

  3. Microstructural evolution and mechanical properties of oil jet peened aluminium alloy, AA6063-T6

    International Nuclear Information System (INIS)

    Arun Prakash, N.; Gnanamoorthy, R.; Kamaraj, M.

    2010-01-01

    Grain size refinement by severe surface plastic deformation is one way of improving the surface properties. This paper describes the microstructural evolution due to severe surface plastic deformation by oil jet peening in aluminium alloy, AA6063-T6. Detail characterization of the treated surfaces using X-ray diffraction analysis and transmission electron microscopy revealed the formation of submicron size grains at and near the surface. The nozzle-traveling velocity decides the peening intensity and coverage and affects the surface properties. The specimen peened at low nozzle-traveling velocity exhibited an ultrafine grain size (∼210 nm) with high surface hardness (∼0.88 GPa), compressive residual stress (-102 ± 7 MPa) and dislocation density. The hardness is high at the surface and the depth of hardened layer is ∼400 μm. Formation of high-density dislocations and associated grain refinement resulted in increased surface hardness. Presence of surface modified layer will be beneficial in improving the fatigue and tribo behavior.

  4. Influence of transport mechanisms on nucleation and grain structure formation in DC cast aluminium alloy ingots

    Science.gov (United States)

    Bedel, M.; Založnik, M.; Kumar, A.; Combeau, H.; Jarry, P.; Waz, E.

    2012-01-01

    The grain structure formation in direct chill (DC) casting is directly linked to nucleation, which is generally promoted by inoculation. Inoculation prevents defects, but also modifies the physical properties by changing the microstructure. We studied the coupling of the nucleation on inoculant particles and the grain growth in the presence of melt flow induced by thermosolutal convection and of the transport of free-floating equiaxed grains. We used a volume-averaged two-phase multiscale model with a fully coupled description of phenomena on the grain scale (nucleation on grain refiner particles and grain growth) and on the product scale (macroscopic transport). The transport of inoculant particles is also modeled, which accounts for the inhomogeneous distribution of inoculant particles in the melt. The model was applied to an industrial sized (350mm thick) DC cast aluminium alloy ingot. A discretised nuclei size distribution was defined and the impact of different macroscopic phenomena on the grain structure formation was studied: the zone and intensity of nucleation and the resulting grain size distribution. It is shown that nucleation in the presence of macroscopic transport cannot be explained only in terms of cooling rate, but variations of composition, nuclei density and grain density, all affected by transport, must be accounted for.

  5. Effects of heat treatments on the microstructure and mechanical properties of a 6061 aluminium alloy

    International Nuclear Information System (INIS)

    Maisonnette, D.; Suery, M.; Nelias, D.; Chaudet, P.; Epicier, T.

    2011-01-01

    Research highlights: → Description of the mechanical behavior of AA6061-T6 at RT after various thermal histories. → A fast-heating device has been designed to reproduce those thermal histories on tensile specimens. → The thermal loadings are representative of the temperature change observed in the HAZ during welding. → The variation of mechanical properties is the result of metallurgical evolution observed by TEM. → The yield stress at RT decreases with the maximum temperature reached during the thermal cycle. - Abstract: This paper describes the mechanical behavior of the 6061-T6 aluminium alloy at room temperature for various previous thermal histories representative of an electron beam welding. A fast-heating device has been designed to control and apply thermal loadings on tensile specimens. Tensile tests show that the yield stress at ambient temperature decreases if the maximum temperature reached increases or if the heating rate decreases. This variation of the mechanical properties is the result of microstructural changes which have been observed by Transmission Electron Microscopy (TEM).

  6. Inhibition of localized attack on the aluminium alloy AA 6351 in glycol/water solutions

    Energy Technology Data Exchange (ETDEWEB)

    Monticelli, C; Brunoro, G; Zucchi, F; Fagioli, F

    1989-06-01

    The objective of this work was to examine the feasibility of enhancing pitting resistance of AA 6351 (nominal composition: 1% Si, 0.6% Mg, 0.3% Mn, balance Al) by adding suitable inhibitors to the solutions. The compounds used were two inorganic salts: sodium molybdate and sodium tungstate and two derivatives of pyrimidine: 2-aminopyrimidine (2AP) and 2-hydroxypyrimidine (2HP). The inhibiting efficiencies of these substances were tested by both short-time electrochemical tests (galvanic coupling tests and polarization curves) and long-time immersions under experimental conditions causing the localized attack. Molybdate, tungstate and, to some extent, also 2AP efficiently inhibit AA 6351 localized corrosion in degraded solutions at 80/sup 0/C and in pure boiling solutions, for long exposure periods. The short-time electrochemical tests suggest that molybdate and tungstate are able to retard the electrochemical processes occurring on both the aluminium alloy and the small copper cathodic area produced by copper deposition. On the other hand, the 2AP efficiency is attributed to some complexing capability of this pyrimidine derivative towards dissolved copper ions, that are stabilized in solution. 2HP does not prevent AA 6351 localized attack. (orig./MM).

  7. Microstructure and micro-texture evolution during large strain deformation of aluminium alloy AA 2219

    Energy Technology Data Exchange (ETDEWEB)

    Murty, S.V.S. Narayana [Materials and Mechanical Entity, Vikram Sarabhai Space Center, Trivandrum-695 022 (India); Sarkar, Aditya [Department of Materials Science and Engineering, Indian Institute of Technology, Gandhinagar-382 424 (India); Narayanan, P. Ramesh; Venkitakrishnan, P.V. [Materials and Mechanical Entity, Vikram Sarabhai Space Center, Trivandrum-695 022 (India); Mukhopadhyay, J. [Department of Materials Science and Engineering, Indian Institute of Technology, Gandhinagar-382 424 (India)

    2016-11-20

    Aluminium alloy AA2219 is widely used in the fabrication of propellant tanks of cryogenic stages of satellite launch vehicles. These propellant tanks are welded structures and a fine grained microstructure is usually preferred for sheets/plates and ring rolled rings used in their fabrication. In order to study the effect of large strain deformation on the microstructural evolution, hot isothermal plane strain compression (PSC) tests were conducted on AA 2219 in the temperature range of 250 °C–400 °C and at strain rates of 0.01 s{sup −1} and 1 s{sup −1}. Flow curves obtained at different temperatures and strain rates exhibited two types of behavior; one with a clear stress peak followed by softening, occurring below Z=2.5E+15 and steady state flow behavior above it. Electron Back-Scatter Diffraction (EBSD) analysis of the PSC tested samples at the location of maximum strain revealed the presence of lamellar microstructures with very low fraction of transverse high angle boundaries (HABs). The loss of HABs during large strain deformation is attributed to the occurrence of dynamic recovery (DRV) as the ratio of calculated to measured lamellar boundary width is less than unity. Based on detailed microstructure and micro texture analysis, it was concluded that it is very difficult to obtain large fraction of HABs through uniaxial large strain deformation. Therefore, to obtain fine grain microstructure in thermo-mechanically processed AA2219 products, multi-axial deformation is essential.

  8. Design and Analysis of Wind Turbine Blade Hub using Aluminium Alloy AA 6061-T6

    Science.gov (United States)

    Ravikumar, S.; Jaswanthvenkatram, V.; Sai kumar, Y. J. N. V.; Sohaib, S. Md.

    2017-05-01

    This work presents the design and analysis of horizontal axis wind turbine blade hub using different material. The hub is very crucial part of the wind turbine, which experience the loads from the blades and the loads were transmitted to the main shaft. At present wind turbine is more expensive and weights more than a million pounds, with the nacelle, rotor hub and blades accounting for most of the weight. In this work Spheroidal graphite cast iron GGG 40.3 is replaced by aluminium alloy 6061-T6 to enhance the casting properties and also to improve the strength-weight ratio. This transition of material leads to reduction in weight of the wind turbine. All the loads caused by wind and extreme loads on the blades are transferred to the hub. Considering the IEC 61400-1 standard for defining extreme loads on the hub the stress and deflection were calculated on the hub by using Finite element Analysis. Result obtained from ANSYS is compared and discussed with the existing design.

  9. In temperature forming of friction stir lap welds in aluminium alloys

    Science.gov (United States)

    Bruni, Carlo; Cabibbo, Marcello; Greco, Luciano; Pieralisi, Massimiliano

    2018-05-01

    The objective of such investigation is the study in depth of the forming phase of welds realized on three sheet metal blanks in aluminium alloys by friction stir lap welding. Such forming phase was performed by upsetting at different constant forming temperatures varying from 200°C to 350°C with constant ram velocities of 0.01 and 0.1 mm/s. The temperature values were obtained by the use of heating strips applied on the upper tool and on the lower tool. It was observed an increase in the friction factor, acting at the upsetting tool-workpiece interface, with increasing temperature that is very useful in producing the required localized deformation with which to improve the weld. It was also confirmed that the forming phase allows to realize a required thickness in the weld area allowing to neglect the surficial perturbation produced by the friction stir welding tool shoulder. The obtained thickness could be subjected to springback when too low temperatures are considered.

  10. Processing and Characterization of NiTi Shape Memory Alloy Particle Reinforced Sn-In Solders

    National Research Council Canada - National Science Library

    Chung, Kohn C

    2006-01-01

    .... In previous work, it was proposed that reinforcement of solder by NiTi shape memory alloy particles to form smart composite solder reduces the inelastic strain of the solder and hence, may enhance...

  11. Experimental investigations of visco-plastic properties of the aluminium and tungsten alloys used in KE projectiles

    Science.gov (United States)

    Kruszka, L.; Magier, M.

    2012-08-01

    The main aim of studies on dynamic behaviour of construction materials at high strain rates is to determine the variation of mechanical properties (strength, plasticity) in function of the strain rate and temperature. On the basis of results of dynamic tests on the properties of constructional materials the constitutive models are formulated to create numerical codes applied to solve constructional problems with computer simulation methods. In the case of military applications connected with the phenomena of gunshot and terminal ballistics it's particularly important to develop a model of strength and armour penetration with KE projectile founded on reliable results of dynamic experiments and constituting the base for further analyses and optimization of projectile designs in order to achieve required penetration depth. Static and dynamic results of strength investigations of the EN AW-7012 aluminium alloy (sabot) and tungsten alloy (penetrator) are discussed in this paper. Static testing was carried out with the INSTRON testing machine. Dynamic tests have been conducted using the split Hopkinson pressure bars technique at strain rates up to 1,2 ṡ 104s-1 (for aluminium alloy) and 6 ṡ 103s-1 (for tungsten alloy).

  12. Experimental investigations of visco-plastic properties of the aluminium and tungsten alloys used in KE projectiles

    Directory of Open Access Journals (Sweden)

    Magier M.

    2012-08-01

    Full Text Available The main aim of studies on dynamic behaviour of construction materials at high strain rates is to determine the variation of mechanical properties (strength, plasticity in function of the strain rate and temperature. On the basis of results of dynamic tests on the properties of constructional materials the constitutive models are formulated to create numerical codes applied to solve constructional problems with computer simulation methods. In the case of military applications connected with the phenomena of gunshot and terminal ballistics it’s particularly important to develop a model of strength and armour penetration with KE projectile founded on reliable results of dynamic experiments and constituting the base for further analyses and optimization of projectile designs in order to achieve required penetration depth. Static and dynamic results of strength investigations of the EN AW-7012 aluminium alloy (sabot and tungsten alloy (penetrator are discussed in this paper. Static testing was carried out with the INSTRON testing machine. Dynamic tests have been conducted using the split Hopkinson pressure bars technique at strain rates up to 1,2 ⋅ 104s−1 (for aluminium alloy and 6 ⋅ 103s−1 (for tungsten alloy.

  13. Effect of aluminium on the passivation of zinc–aluminium alloys in artificial seawater at 80 °C

    International Nuclear Information System (INIS)

    Kaewmaneekul, Tanapat; Lothongkum, Gobboon

    2013-01-01

    Highlights: ► Pure Zn and Zn–Al alloys passivate and depassivate in artificial seawater. ► Al retards passivation of Zn–Al alloys. ► Passive film composes of the inner film and the outer charge transfer layers. ► Al increases current density but decreases corrosion resistance of passive films. ► Al increases the electrical conductivity and the capacitance of the films. - Abstract: The effect of Al (0.15, 0.3 and 1.0 wt.%) on the passivation of Zn–Al alloys in artificial seawater at 80 °C is investigated by electrochemical measurements, scanning electron microscopy (SEM) and X-ray diffraction (XRD). It is found that the presence of Al in Zn–Al alloys can retard passivation. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements show that Al increases the current density but decreases the corrosion resistance of passive films, respectively. Mott-Schottky analysis reveals that Al increases the electrical conductivity and the capacitance of the films. Passivation of Zn–Al alloys occurs in artificial seawater when the immersion time is between 120 and 288 h, due to the presence of various Zn and Al protective compounds at the surfaces. Depassivation occurs when the immersion time is between 288 and 720 h, probably due to the decrease of solution pH and the Cl − penetration mechanism.

  14. [Effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker].

    Science.gov (United States)

    Zhu, Ming-yi; Zhang, Xiu-yin

    2015-06-01

    To evaluate the effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker (ABW). ABW was surface-treated with 0%, 1%, 2%, 3% and 4% silan coupling agent (γ-MPS), and mixed with resin matrix to synthesize 5 groups of composite resins. After heat-cured at 120 degrees centigrade for 1 h, specimens were tested in three-point flexure to measure strength according to ISO-4049. One specimen was selected randomly from each group and observed under scanning electron microscope (SEM). The data was analyzed with SAS 9.2 software package. The flexural strength (117.93±11.9 Mpa) of the group treated with 2% silane coupling agent was the highest, and significantly different from that of the other 4 groups (α=0.01). The amount of silane coupling agent has impact on the flexural strength of dental composite resins reinforced with whiskers; The flexual strength will be reduced whenever the amount is higher or lower than the threshold. Supported by Research Fund of Science and Technology Committee of Shanghai Municipality (08DZ2271100).

  15. Investigation of planetary milling for nano-silicon carbide reinforced aluminium metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Kollo, Lauri, E-mail: lauri.kollo@staff.ttu.e [Laboratory of Advanced Materials Processing, EMPA, Feuerwerkerstrasse 39, 3602 Thun (Switzerland); Department of Materials Engineering, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Leparoux, Marc; Bradbury, Christopher R.; Jaeggi, Christian [Laboratory of Advanced Materials Processing, EMPA, Feuerwerkerstrasse 39, 3602 Thun (Switzerland); Carreno-Morelli, Efrain; Rodriguez-Arbaizar, Mikel [University of Applied Sciences of Western Switzerland, Design and Materials Unit, 1950 Sion (Switzerland)

    2010-01-21

    High-energy planetary milling was used for mixing aluminium powders with 1 vol.% of silicon carbide (SiC) nanoparticles. A number of milling parameters were modified for constituting the relationship between the energy input from the balls and the hardness of the bulk nanocomposite materials. It was shown that mixing characteristics and reaction kinetics with stearic acid as process control agent can be estimated by normalised input energy from the milling bodies. For this, the additional parameter characterising the vial filling was determined experimentally. Depending on the ball size, a local minimum in filling parameter was found, laying at 25 or 42% filling of the vial volume for the balls with diameter of 10 and 20 mm, respectively. These regions should be avoided to achieve the highest milling efficiency.After a hot compaction, fourfold difference of hardness for different milling conditions was detected. Therewith the hardness of the Al-1 vol.% nanoSiC composite could be increased from 47 HV{sub 0.5} of pure aluminium to 163 HV{sub 0.5} when milling at the highest input energy levels.

  16. In-vitro characterization of stress corrosion cracking of aluminium-free magnesium alloys for temporary bio-implant applications.

    Science.gov (United States)

    Choudhary, Lokesh; Singh Raman, R K; Hofstetter, Joelle; Uggowitzer, Peter J

    2014-09-01

    The complex interaction between physiological stresses and corrosive human body fluid may cause premature failure of metallic biomaterials due to the phenomenon of stress corrosion cracking. In this study, the susceptibility to stress corrosion cracking of biodegradable and aluminium-free magnesium alloys ZX50, WZ21 and WE43 was investigated by slow strain rate tensile testing in a simulated human body fluid. Slow strain rate tensile testing results indicated that each alloy was susceptible to stress corrosion cracking, and this was confirmed by fractographic features of transgranular and/or intergranular cracking. However, the variation in alloy susceptibility to stress corrosion cracking is explained on the basis of their electrochemical and microstructural characteristics. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Modification of aluminium alloys with rare metals – the basis for advanced materials in construction and transport

    Directory of Open Access Journals (Sweden)

    Skachkov Vladimir Mikchaylovich

    2016-06-01

    Full Text Available The method of process powder injection into aluminum melt shows much promise. Scandium is injected by the high-temperature exchange reaction between the salt melt and aluminum. The best salt compositions were selected. The results of the process are considered to depend on the initial salts. A series of fusions was performed under production conditions at the Kamensk-Uralskii metallurgical plant. It was shown that the injection method for production of aluminoscandium master alloys is technologically feasible. To protect intellectual property of authors, employees of the Institute of Solid State Chemistry, Ural branch of RAS (Russia a patent «Method of alloying of aluminium or alloys on its basis» RU № 2534182 of 27.11.2014 was registered.

  18. Industrial based volume manufacturing of lightweight aluminium alloy panel components with high-strength and complex-shape for car body and chassis structures

    Science.gov (United States)

    Anyasodor, Gerald; Koroschetz, Christian

    2017-09-01

    To achieve the high volume manufacture of lightweight passenger cars at economic cost as required in the automotive industry, low density materials and new process route will be needed. While high strength aluminium alloy grades: AA7075 and AA6082 may provide the alternative material solution, hot stamping process used for high-strength and ultrahigh strength steels such as boron steel 22mnb5 can enable the volume manufacture of panel components with high-strength and complex-shape for car body and chassis structures. These aluminium alloy grades can be used to manufacture panel components with possible yield strengths ≥ 500 MPa. Due to the differences in material behaviors, hot stamping process of 22mnb5 cannot be directly applied to high strength aluminium alloy grades. Despite recorded successes in laboratories, researches and niche hot forming processes of high strength aluminium alloy grades, not much have been achieved for adequate and efficient volume manufacturing system applicable in the automotive industry. Due to lack of such system and based on expert knowledge in hot stamping production-line, AP&T presents in this paper a hot stamping processing route for high strength aluminium alloys been suitable for production-line development and volume manufacturing.

  19. Aluminium in Infrastructures

    NARCIS (Netherlands)

    Maljaars, J.

    2016-01-01

    Aluminium alloys are used in infrastructures such as pedestrian bridges or parts of it such as handrail. This paper demonstrates that aluminium alloys are in principle also suited for heavy loaded structures, such as decks of traffic bridges and helicopter landing platforms. Recent developments in

  20. Examination of the effect of Sc on 2000 and 7000 series aluminium alloy castings: for improvements in fusion welding

    International Nuclear Information System (INIS)

    Norman, A.F.; Hyde, K.; Costello, F.; Thompson, S.; Birley, S.; Prangnell, P.B.

    2003-01-01

    It has been reported that small additions of scandium (Sc) can improve the weldability and mechanical properties of some aluminium aerospace alloys that are normally considered to be 'unweldable'. In order to determine the mechanisms by which these improvements occur, and more rapidly arrive at optimum Sc addition levels, small wedge-shaped castings have been used to simulate the cooling rates found in MIG/TIG welds. Using this technique, a range of Sc addition levels have been made to two typical Al-aerospace alloys, 2024 and 7475. It has been found that when the Sc level exceeds a critical concentration, small Al 3 Sc primary particles form in the melt and act as very efficient grain nucleants, resulting in simulated fusion zone grain sizes as fine as 15 μm. This exceptional level of grain refinement produced an unusual grain structure that exhibited no dendritic, or cellular, substructure and a large increase in strength and ductility of the castings. Sc also produced changes in the alloy's freezing paths, which cannot yet be fully explained, but led to the appearance of the W phase in the 2024 alloy and, in both alloys, an overall reduction in the amount of eutectic formed during solidification. When coupled with the high level of grain refinement, this behaviour could be used to explain the increased strength and ductility of the castings. In 2000 and 7000 series aluminium alloys, it is therefore, anticipated that optimised Sc bearing filler wires will significantly improve the mechanical properties of the weld metal, as well as reducing the tendency for solidification cracking

  1. Effect of friction time on the properties of friction welded YSZ‐alumina composite and 6061 aluminium alloy

    Directory of Open Access Journals (Sweden)

    Uday M. Basheer

    2012-03-01

    Full Text Available The aim of this work was to study the effect of friction time on the microstructure and mechanical properties of alumina 0, 25, 50 wt% yttria stabilized zirconia (YSZ composite and 6061 aluminium alloy joints formed by friction welding. The alumina-YSZ composites were prepared through slip casting in plaster of Paris molds (POP and subsequently sintered at 1600°C, while the aluminium rods were machined down using a lathe machine to the dimension required. The welding process was carried out under different rotational speeds and friction times, while friction force (0.5 ton-force was kept constant. Scanning electron microscopy was used to characterize the interface of the joints structure. The experimental results showed that the friction time has a significant effect on joint structure and mechanical properties.

  2. Influence of friction stir welding process and tool parameters on strength properties of AA7075-T6 aluminium alloy joints

    International Nuclear Information System (INIS)

    Rajakumar, S.; Muralidharan, C.; Balasubramanian, V.

    2011-01-01

    The aircraft aluminium alloys generally present low weldability by traditional fusion welding process. The development of the friction stir welding has provided an alternative improved way of satisfactorily producing aluminium joints, in a faster and reliable manner. In this present work, the influence of process and tool parameters on tensile strength properties of AA7075-T 6 joints produced by friction stir welding was analysed. Square butt joints were fabricated by varying process parameters and tool parameters. Strength properties of the joints were evaluated and correlated with the microstructure, microhardness of weld nugget. From this investigation it is found that the joint fabricated at a tool rotational speed of 1400 rpm, welding speed of 60 mm/min, axial force of 8 kN, using the tool with 15 mm shoulder diameter, 5 mm pin diameter, 45 HRc tool hardness yielded higher strength properties compared to other joints.

  3. Hydrogen analysis and effect of filtration on final quality of castings from aluminium alloy AlSi7Mg0,3

    Directory of Open Access Journals (Sweden)

    M. Brůna

    2011-01-01

    Full Text Available The usage of aluminium and its alloys have increased in many applications and industries over the decades. The automotive industry is the largest market for aluminium castings and cast products. Aluminium is widely used in other applications such as aerospace, marine engines and structures. Parts of small appliances, hand tools and other machinery also use thousands of different aluminium castings. The applications grow as industry seeks new ways to save weight and improve performance and recycling of metals has become an essential part of a sustainable industrial society. The process of recycling has therefore grown to be of great importance, also another aspect has become of critical importance: the achievement of quality and reliability of the products and so is very important to underst and the mechanisms of the formation of defects in aluminium melts, and also to have a reliable and simple means of detection.

  4. Analysis of the tool plunge in friction stir welding - comparison of aluminium alloys 2024 T3 and 2024 T351

    Directory of Open Access Journals (Sweden)

    Veljić Darko

    2016-01-01

    Full Text Available Temperature, plastic strain and heat generation during the plunge stage of the friction stir welding (FSW of high-strength aluminium alloys 2024 T3 and 2024 T351 are considered in this work. The plunging of the tool into the material is done at different rotating speeds. A three-dimensional finite element (FE model for thermomechanical simulation is developed. It is based on arbitrary Lagrangian-Eulerian formulation, and Johnson-Cook material law is used for modelling of material behaviour. From comparison of the numerical results for alloys 2024 T3 and 2024 T351, it can be seen that the former has more intensive heat generation from the plastic deformation, due to its higher strength. Friction heat generation is only slightly different for the two alloys. Therefore, temperatures in the working plate are higher in the alloy 2024 T3 for the same parameters of the plunge stage. Equivalent plastic strain is higher for 2024 T351 alloy, and the highest values are determined under the tool shoulder and around the tool pin. For the alloy 2024 T3, equivalent plastic strain is the highest in the influence zone of the tool pin. [Projekat Ministarstva nauke Republike Srbije, br. TR 34016 i br. TR 35006

  5. Evolution of mechanical behavior of 6XXX aluminium alloy due to the precipitation state during a thermo-mechanical process

    International Nuclear Information System (INIS)

    Bardel, Didier; Perez, Michel; Nelias, Daniel; Chaise, Thibaut; Garnier, Jerome; Bourlier, Florent

    2014-01-01

    The aim of this research is to link the microstructural state and the mechanical properties of an age hardening alloy during a fast heat treatment such as encountered during welding. A coupled model between precipitation state and mechanical properties is used to predict the yield strength and hardening behavior that can be observed experimentally. The method permits the identification of the kinematic and isotropic contributions in the hardening model. The methodology is applied to a 6061-T6 aluminium alloy which is used in the Jules Horowitz reactor vessel. The general idea of this methodology is to couple an efficient microstructural model to a mechanical one based on the dislocation theory and ad'hoc experiments. The theoretical background is based on the work of Kampmann and Wagner, known as the KWN model, to account for nucleation, growth/dissolution and coarsening of precipitates. This analysis requires transient thermo-mechanical experimental data. The efficiency of these models and their coupling are shown for a series 6XXX aluminium alloy which contains β'' and β' precipitates. Ultimately these models are coupled to a FEA model and allows to predict the distribution of precipitates within each element of the mesh, and subsequently its mechanical behavior. (authors)

  6. Zirconium behaviour during electrorefining of actinide-zirconium alloy in molten LiCl-KCl on aluminium cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Meier, R. [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, Karlsruhe 76125 (Germany); Heidelberg University, Institute of Physical Chemistry, Im Neuenheimer Feld 253, Heidelberg 69120 (Germany); Souček, P., E-mail: Pavel.Soucek@ec.europa.eu [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, Karlsruhe 76125 (Germany); Malmbeck, R.; Krachler, M.; Rodrigues, A.; Claux, B.; Glatz, J.-P. [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, Karlsruhe 76125 (Germany); Fanghänel, Th. [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, Karlsruhe 76125 (Germany); Heidelberg University, Institute of Physical Chemistry, Im Neuenheimer Feld 253, Heidelberg 69120 (Germany)

    2016-04-15

    A pyrochemical electrorefining process for the recovery of actinides from metallic nuclear fuel based on actinide-zirconium alloys (An–Zr) in a molten salt is being investigated. In this process actinides are group-selectively recovered on solid aluminium cathodes as An–Al alloys using a LiCl–KCl eutectic melt at a temperature of 450 °C. In the present study the electrochemical behaviour of zirconium during electrorefining was investigated. The maximum amount of actinides that can be oxidised without anodic co-dissolution of zirconium was determined at a selected constant cathodic current density. The experiment consisted of three steps to assess the different stages of the electrorefining process, each of which employing a fresh aluminium cathode. The results indicate that almost a complete dissolution of the actinides without co-dissolution of zirconium is possible under the applied experimental conditions. - Highlights: • Recovery of actinides was shown by electrorefining of U/Pu–Zr alloys in LiCl–KCl. • Constant current density of 20 mA/cm{sup 2} is applied. • Most of the actinides were dissolved avoiding zirconium co-dissolution. • Deterioration of the deposit quality by a small amount of co-deposited Zr is not observed.

  7. Effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded high strength aluminium alloy

    International Nuclear Information System (INIS)

    Balasubramanian, V.; Ravisankar, V.; Reddy, G. Madhusudhan

    2007-01-01

    This paper reveals the effect of pulsed current and post weld aging treatment on tensile properties of argon arc welded AA7075 aluminium alloy. This alloy has gathered wide acceptance in the fabrication of light weight structures requiring high strength-to-weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. The preferred welding processes of high strength aluminium alloy are frequently gas tungsten arc welding (GTAW) process and gas metal arc welding (GMAW) process due to their comparatively easier applicability and better economy. Weld fusion zones typically exhibit coarse columnar grains because of the prevailing thermal conditions during weld metal solidification. This often results inferior weld mechanical properties and poor resistance to hot cracking. In this investigation, an attempt has been made to refine the fusion zone grains by applying pulsed current welding technique. Four different welding techniques have been used to fabricate the joints and they are: (i) continuous current GTAW (CCGTAW), (ii) pulsed current GTAW (PCGTAW), (iii) continuous current GMAW (CCGMAW) and (iv) pulsed current GMAW (PCGMAW) processes. As welded joint strength is much lower than the base metal strength and hence, a simple aging treatment has been given to improve the tensile strength of the joints. Current pulsing leads to relatively finer and more equi-axed grain structure in GTA and GMA welds. In contrast, conventional continuous current welding resulted in predominantly columnar grain structures. Post weld aging treatment is accompanied by an increase in tensile strength and tensile ductility

  8. The study of intergranular corrosion in aircraft aluminium alloys using X-ray tomography

    International Nuclear Information System (INIS)

    Knight, S.P.; Salagaras, M.; Trueman, A.R.

    2011-01-01

    Research highlights: → IGC is stochastic, where initiation is statistical and growth kinetics was somewhat predictable. → Dissolved oxygen concentration was more important than the concentration of salt in the droplet. → A limiting depth occurred for AA2024, whereas no limiting depth occurs for AA7050 after 168 h exposure. → A limiting depth may be controlled by the transport of dissolved oxygen down the corrosion fissure. → A limiting IGC depth is dependent on the overpotential of the SDZ (adjacent to the grain boundary). - Abstract: Atmospheric corrosion is one of the leading causes of structural damage to aircraft. Of particular importance is pitting and intergranular corrosion, which can develop into fatigue cracks, stress corrosion cracks, or exfoliation. Therefore it is of interest to the Australian Defence Force (ADF) to understand how corrosion ensues in susceptible aircraft aluminium alloys, such as AA2024-T351 and 7050-T7451. However, there are many difficulties in measuring the extent of intergranular corrosion, since it is predominantly hidden below the surface. Traditionally, cross-sectioning has been used to view and measure the depth of attack. In the present work, 2 mm diameter pin specimens were contaminated with a droplet of 3.5% NaCl and exposed to constant humidity that resulted in intergranular corrosion. X-ray computed tomography was then used to non-destructively assess the depth and volume of corrosion both as a function of time in 97% relative humidity, and as a function of relative humidity after 168 h exposure. Both corrosion depth and volume increased with time, but there was evidence for a limiting depth in AA2024. Depth and volume also increased with relative humidity of the environment, for which the time-of-wetness and oxygen concentration of the droplets were considered the important factors in driving the corrosion process.

  9. Electromagnetic Gauge Study of Laser-Induced Shock Waves in Aluminium Alloys

    Science.gov (United States)

    Peyre, P.; Fabbro, R.

    1995-12-01

    The laser-shock behaviour of three industrial aluminum alloys has been analyzed with an Electromagnetic Gauge Method (EMV) for measuring the velocity of the back free surface of thin foils submitted to plane laser irradiation. Surface pressure, shock decay in depth and Hugoniot Elastic Limits (HEL) of the materials were investigated with increasing thicknesses of foils to be shocked. First, surface peak pressures values as a function of laser power density gave a good agreement with conventional piezoelectric quartz measurements. Therefore, comparison of experimental results with computer simulations, using a 1D hydrodynamic Lagrangian finite difference code, were also in good accordance. Lastly, HEL values were compared with static and dynamic compressive tests in order to estimate the effects of a very large range of strain rates (10^{-3} s^{-1} to 10^6 s^{-1}) on the mechanical properties of the alloys. Cet article fait la synthèse d'une étude récente sur la caractérisation du comportement sous choc-laser de trois alliages d'aluminium largement utilisés dans l'industrie à travers la méthode dite de la jauge électromagnétique. Cette méthode permet de mesurer les vitesses matérielles induites en face arrière de plaques d'épaisseurs variables par un impact laser. La mise en vitesse de plaques nous a permis, premièrement, de vérifier la validité des pressions d'impact superficielles obtenues en les comparant avec des résultats antérieurs obtenus par des mesures sur capteurs quartz. Sur des plaques d'épaisseurs croissantes, nous avons caractérisé l'atténuation des ondes de choc en profondeur dans les alliages étudiés et mesuré les limites d'élasticité sous choc (pressions d'Hugoniot) des alliages. Les résultats ont été comparés avec succès à des simulations numériques grâce à un code de calcul monodimensionnel Lagrangien. Enfin, les valeurs des pressions d'Hugoniot mesurées ont permis de tracer l'évolution des contraintes d

  10. Studies of the subsurface zone created in aluminium and its alloys by means of positron annihilation and complementary methods

    International Nuclear Information System (INIS)

    Dryzek, E.

    2008-01-01

    There are presented the results of the studies of the subsurface zone created in aluminium and its alloys during sliding or other surface modification treatments. The application of the positron annihilation techniques due to their high sensitivity to crystal lattice defects enabled to determine defects profiles in the subsurface zone. The positron annihilation studies were correlated with other conventional measurements applied in tribology, i.e. microhardness measurements, scanning electron microscopy, X-ray diffraction and in a special case stress distribution calculated theoretically. It was shown that the positron annihilation spectroscopy is a useful tool for profiling of the subsurface zone created during sliding even for light metals their alloys and composites. The total range of the subsurface zone detected by the positron annihilation extends from 50 μm to 450 μm depending on the material studied and surface modification treatment. Additionally, the type of the main defects can be determined. The studies of the pure aluminium samples after dry sliding enabled to find the defect concentration of vacancy type in the depth less then 1 μm and to correlate its value with the size of crystallites. It supports the conclusion on recovery processes taking place in this layer. There was made the attempt to apply the Doppler broadening coincidence spectroscopy to the studies of aluminium alloy and composite. In view of the interdisciplinary character the present thesis enclose also the review of the basic issues of tribology, measurement methods applied to the subsurface zone studies and positron annihilation experimental techniques. (author)

  11. Accelerated growth of oxide film on aluminium alloys under steam: Part II: Effects of alloy chemistry and steam vapour pressure on corrosion and adhesion performance

    DEFF Research Database (Denmark)

    Din, Rameez Ud; Bordo, Kirill; Jellesen, Morten Stendahl

    2015-01-01

    The steam treatment of aluminium alloys with varying vapour pressure of steamresulted in the growth of aluminium oxyhydroxide films of thickness range between 450 - 825nm. The surface composition, corrosion resistance, and adhesion of the produced films was characterised by XPS, potentiodynamic p...... of the vapour pressure of the steam. The accelerated corrosion and adhesion tests on steam generated oxide films with commercial powder coating verified that the performance of the oxide coating is highly dependent on the vapour pressure of the steam....... polarization, acetic acid salt spray, filiform corrosion test, and tape test. The oxide films formed by steam treatment showed good corrosion resistance in NaCl solution by significantly reducing anodic and cathodic activities. The pitting potential of the surface treated with steam was a function...

  12. Continuum damage mechanics based approach to the fatigue life prediction of cast aluminium alloy with considering the effect of porosity

    Directory of Open Access Journals (Sweden)

    Wang Xiaojia

    2018-01-01

    Full Text Available A damage mechanics based approach is applied for the study of fatigue behaviour of high pressure die cast ADC12 aluminium alloy. A damage coupled elastoplastic constitutive model is presented according to the concept of effective stress and the hypothesis of strain equivalence. An elastic fatigue damage model taking into account the pore-induced stress concentration is developed to investigate fatigue damage evolution of the specimens subjected to cyclic loading. The predicted lives for the specimens with different sizes of pores are consistent with the experimental data. The pore-induced fatigue damage and the variation of fatigue life along with the size of pores are also investigated.

  13. Identification of mechanical properties of weld joints of AlMgSi07.F25 aluminium alloy

    Directory of Open Access Journals (Sweden)

    P. Kopas

    2017-01-01

    Full Text Available The aim of this paper is to present the analysis of selected mechanical properties of weld joints of AlMgSi07.F25 aluminium alloy. We will focus on the influence of the test bar neck shape on the tensile strength characteristics and the course of hardness in the weld joint cross-section. For the welding process using TIG (Tungsten Inert Gas technology we considered AlSi5 as the additive material. This paper also includes a short study of numerical modelling of the test bar welding.

  14. Optimization of squeeze casting parameters for non symmetrical AC2A aluminium alloy castings through Taguchi method

    International Nuclear Information System (INIS)

    Senthil, P.; Amirthagadeswaran, K. S.

    2012-01-01

    This paper reports a research in which an attempt was made to prepare AC2A aluminium alloy castings of a non symmetrical component through squeeze casting process. The primary objective was to investigate the influence of process parameters on mechanical properties of the castings. Experiments were conducted based on orthogonal array suggested in Taguchi's offline quality control concept. The experimental results showed that squeeze pressure, die preheating temperature and compression holding time were the parameters making significant improvement in mechanical properties. The optimal squeeze casting condition was found and mathematical models were also developed for the process

  15. Load carrying capacity of RCC beams by replacing steel reinforcement bars with shape memory alloy bars

    Science.gov (United States)

    Bajoria, Kamal M.; Kaduskar, Shreya S.

    2016-04-01

    In this paper the structural behavior of reinforced concrete (RC) beams with smart rebars under two point loading system has been numerically studied, using Finite Element Method. The material used in this study is Super-elastic Shape Memory Alloys (SE SMAs) which contains nickel and titanium. In this study, different quantities of steel and SMA rebars have been used for reinforcement and the behavior of these models under two point bending loading system is studied. A comparison of load carrying capacity for the model between steel reinforced concrete beam and the beam reinforced with S.M.A and steel are performed. The results show that RC beams reinforced with combination of shape memory alloy and steel show better performance.

  16. The mechanical properties of magnesium matrix composites reinforced with 10 wt.% W14Al86 alloy particles

    International Nuclear Information System (INIS)

    Tang, H.G.; Ma, X.F.; Zhao, W.; Cai, S.G.; Zhao, B.; Qiao, Z.H.

    2007-01-01

    The Mg-based metal matrix composite reinforced by 10 wt.% W 14 Al 86 alloy particles has been prepared by mechanical alloying and press-forming process. X-ray diffraction studies confirm the formation of the composite. Microstructure characterization of the samples reveals the uniform distribution of fine W 14 Al 86 alloy. Mechanical properties characterization revealed that the reinforcement of W 14 Al 86 alloy lead to a significant increase in hardness and tensile strength of Mg and AZ91

  17. Dispersoid reinforced alloy powder and method of making

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iver E.; Terpstra, Robert L.

    2017-12-05

    A method of making dispersion-strengthened alloy particles involves melting an alloy having a corrosion and/or oxidation resistance-imparting alloying element, a dispersoid-forming element, and a matrix metal wherein the dispersoid-forming element exhibits a greater tendency to react with a reactive species acquired from an atomizing gas than does the alloying element. The melted alloy is atomized with the atomizing gas including the reactive species to form atomized particles so that the reactive species is (a) dissolved in solid solution to a depth below the surface of atomized particles and/or (b) reacted with the dispersoid-forming element to form dispersoids in the atomized particles to a depth below the surface of said atomized particles. The atomized alloy particles are solidified as solidified alloy particles or as a solidified deposit of alloy particles. Bodies made from the dispersion strengthened alloy particles, deposit thereof, exhibit enhanced fatigue and creep resistance and reduced wear as well as enhanced corrosion and/or oxidation resistance at high temperatures by virtue of the presence of the corrosion and/or oxidation resistance imparting alloying element in solid solution in the particle alloy matrix.

  18. Dispersoid reinforced alloy powder and method of making

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iver E.; Terpstra, Robert L.

    2017-10-10

    A method of making dispersion-strengthened alloy particles involves melting an alloy having a corrosion and/or oxidation resistance-imparting alloying element, a dispersoid-forming element, and a matrix metal wherein the dispersoid-forming element exhibits a greater tendency to react with a reactive species acquired from an atomizing gas than does the alloying element. The melted alloy is atomized with the atomizing gas including the reactive species to form atomized particles so that the reactive species is (a) dissolved in solid solution to a depth below the surface of atomized particles and/or (b) reacted with the dispersoid-forming element to form dispersoids in the atomized particles to a depth below the surface of said atomized particles. The atomized alloy particles are solidified as solidified alloy particles or as a solidified deposit of alloy particles. Bodies made from the dispersion strengthened alloy particles, deposit thereof, exhibit enhanced fatigue and creep resistance and reduced wear as well as enhanced corrosion and/or oxidation resistance at high temperatures by virtue of the presence of the corrosion and/or oxidation resistance imparting alloying element in solid solution in the particle alloy matrix.

  19. Investigation on corrosion and wear behaviors of nanoparticles reinforced Ni-based composite alloying layer

    International Nuclear Information System (INIS)

    Xu Jiang; Tao Jie; Jiang Shuyun; Xu Zhong

    2008-01-01

    In order to investigate the role of amorphous SiO 2 particles in corrosion and wear resistance of Ni-based metal matrix composite alloying layer, the amorphous nano-SiO 2 particles reinforced Ni-based composite alloying layer has been prepared by double glow plasma alloying on AISI 316L stainless steel surface, where Ni/amorphous nano-SiO 2 was firstly predeposited by brush plating. The composition and microstructure of the nano-SiO 2 particles reinforced Ni-based composite alloying layer were analyzed by using SEM, TEM and XRD. The results indicated that the composite alloying layer consisted of γ-phase and amorphous nano-SiO 2 particles, and under alloying temperature (1000 deg. C) condition, the nano-SiO 2 particles were uniformly distributed in the alloying layer and still kept the amorphous structure. The corrosion resistance of composite alloying layer was investigated by an electrochemical method in 3.5%NaCl solution. Compared with single alloying layer, the amorphous nano-SiO 2 particles slightly decreased the corrosion resistance of the Ni-Cr-Mo-Cu alloying layer. X-ray photoelectron spectroscopy (XPS) revealed that the passive films formed on the composite alloying consisted of Cr 2 O 3 , MoO 3 , SiO 2 and metallic Ni and Mo. The dry wear test results showed that the composite alloying layer had excellent friction-reduced property, and the wear weight loss of composite alloying layer was less than 60% of that of Ni-Cr-Mo-Cu alloying layer

  20. Quantitative assessment of liquid Ga penetration into an aluminium alloy by high-resolution X-ray tomography

    International Nuclear Information System (INIS)

    Ohgaki, T.; Toda, H.; Sinclair, I.; Buffiere, J.-Y.; Ludwig, W.; Kobayashi, T.; Niinomi, M.; Akahori, T.

    2005-01-01

    We have evaluated the liquid Ga penetration into an aluminium alloy by high-resolution X-ray tomography. The 3D visualization of a crack together with its surrounding grain structure was performed with the help of the Ga penetration technique. It is found that the advance directions of the crack-tip were strongly influenced by the grain microstructure and the branching of the crack is affected by grain distribution. In this study, the liquid Ga not only acts as a contrast agent for grain boundaries, but also expands the volume of the Al alloy due to Ga diffusion and associated processes. The 3D strain between the grains has been determined by microstructural gauging technique, which uses micropores as marker points. The 3D expansion of the sample volume, the volume reduction of micropores and the brittle fracture were evidently observed

  1. INVESTIGATION OF EFFECT OF COOLING CONDITIONS ON HARDNESS OF THE AA 2024 AND AA 2014 WROUGHT ALUMINIUM ALLOYS

    Directory of Open Access Journals (Sweden)

    Hülya KAÇAR DURMUŞ

    2003-01-01

    Full Text Available Mechanical properties of some aluminum alloys can be changed with precipitation hardening. This intermetallic precipitates are incoherent with the main structure and increased mechanical properties. Cooling rates after solid solution process effects properties after precipitation. In applications, however this is not taken into consideration. In this study, AA 2014 and AA 2024 Aluminium Alloy specimens were hold for one hour at 495±3 0C and formed a solid solution. Specimens were quenched at this temperature with different cooling rtes . later artificial aging was applied at 150 0C and 180 0C. The hardness and microstructure variations of the specimens were investigated depending on the cooling rates and artificial aging temperatures.

  2. Experimental Investigation of Thermal Properties in Glass Fiber Reinforced with Aluminium

    Science.gov (United States)

    Irudaya raja, S. Joseph; Vinod Kumar, T.; Sridhar, R.; Vivek, P.

    2017-03-01

    A test method of a Guarded heat flow meter are used to measure the thermal conductivity of glass fiber and filled with a aluminum powder epoxy composites using an instrument in accordance with ASTM. This experimental study reveals that the incorporation of aluminum and glass fiber reinforced results in enhancement of thermal conductivity of epoxy resin and thereby improves its heat transfer capability. Fiber metal laminates are good candidates for advanced automobile structural applications due to their high categorical mechanical and thermal properties. The most consequential factor in manufacturing of these laminates is the adhesive bonding between aluminum and FRP layers. Here several glass-fiber reinforced aluminum were laminates with different proportion of bonding adhesion were been manufactured. It was observed that the damage size is more preponderant in laminates with poor interfacial adhesion compared to that of laminates with vigorous adhesion between aluminum and glass layers numerically calculated ones and it is found that the values obtained for various composite models using experimental testing method.

  3. Some of the properties of plutonium and the aluminium-plutonium alloy; Quelques proprietes du plutonium et de l'alliage aluminium-plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Abramson, R; Boucher, R; Fabre, R; Monti, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-07-01

    1- Study of the physical properties of plutonium. 1) Study of the allotropy of plutonium. a) Thermal analysis: the apparatus used and the measurement technique are briefly described. The transition point temperatures and the corresponding heats of transformation have been determined. Finally, the results of the particular study of certain transition points are given. b) Dilatometry. The dilatometric analysis of the phase changes of plutonium has been carried out by means of the Chevenard dilatometer with photographic recording. The testing conditions (heating and cooling speeds, isotherm plateaux) have been varied in order to determine accurately the characteristics of each transition, particularly the {delta} {yields} {gamma} transition on cooling. 2) Micrography of plutonium. For the accurate preparation of metallographic samples the electrolytic polishing must be rapid, which implies a mechanical polishing of excellent quality. Information is given on new attacking reagents which show the structure of the metal very clearly. 2- Study of aluminium-plutonium alloys. Comparative study of Al-Pu and Al-U alloys rich in aluminium. a) Thermal analysis. The liquids and fusion temperatures of the eutectic Al-XAl{sub 4}, have been accurately determined. From the measurement of the heats of fusion the exact composition of the eutectic alloy has been determined. b) Thermal treatments. The eutectic coalescence kinetics have been studied by a micrographic method and by following the evolution of hardness. The results obtained show that the phenomenon is more rapid in Al-Pu alloys than in Al-U alloys. c) Micrographic study of the transition XAl{sub 3} {yields} XAl{sub 4}. The peritectic reaction XAl{sub 3} + liq. {yields} XAl{sub 4} has been suppressed by quenching. The transformation of the XAl{sub 3} phase to the solid phase has been studied as well as the effect of small additions of silicon on the kinetics of this reaction. (author) [French] 1- Etude des proprietes

  4. Experimental and numerical investigation on under-water friction stir welding of armour grade AA2519-T87 aluminium alloy

    Directory of Open Access Journals (Sweden)

    S. Sree Sabari

    2016-08-01

    Full Text Available Friction stir welding (FSW is a promising welding process that can join age hardenable aluminium alloys with high joint efficiency. However, the thermal cycles experienced by the material to be joined during FSW resulted in the deterioration of mechanical properties due to the coarsening and dissolution of strengthening precipitates in the thermo-mechanical affected zone (TMAZ and heat affected zone (HAZ. Under water friction stir welding (UWFSW is a variant of FSW process which can maintain low heat input as well as constant heat input along the weld line. The heat conduction and dissipation during UWFSW controls the width of TMAZ and HAZ and also improves the joint properties. In this investigation, an attempt has been made to evaluate the mechanical properties and microstructural characteristics of AA2519-T87 aluminium alloy joints made by FSW and UWFSW processes. Finite element analysis has been used to estimate the temperature distribution and width of TMAZ region in both the joints and the results have been compared with experimental results and subsequently correlated with mechanical properties.

  5. Bonding of aluminium matrix composites for application in the transport industry

    International Nuclear Information System (INIS)

    Urena, A.; Gomez de Salazar, J.M.

    1993-01-01

    A discontinuously reinforced MMC containing 12 vol % SiC particles in an Al-Cu-Mg alloy (AA 2124) matrix has been diffusion bonded. Thick interlayers of different superplastic aluminium alloys (Al-Li 8090 and Al-Cu SUPRAL) were used to reduce the bonding pressure and ensure complete surface contact. Microstructural studies shown higher continuity in joints bonded with 8090 interlayer than with other alloys. Precipitation of rich-copper intermetallic was detected, after bonding, in the interlayer because diffusion of Cu from 2124 matrix. Results suggest that Li contained in the interlayer favours the partial disruption of the aluminium oxide film, making easier the solid state bonding. (orig.)

  6. Optimizing the Parameters in Heat Treatment for Achieving High Hardness and Efficient Bending of Thin BS 2014 Aluminium Alloy Sheets

    Directory of Open Access Journals (Sweden)

    Abirami Priyadarshini B.

    2016-05-01

    Full Text Available The present work targets in setting a standard heat treatment procedure for obtaining high hardness values of the order of 80 HRB in BS 2014 aluminium alloy sheets of 2mm thick commonly used in aerospace industries. A hardness range of 60HRB to 72HRB is possible in low thickness sheets as stated in the standard BS EN 485-2:2013. Experiments were performed to achieve higher hardness values by controlling the heat treatment temperatures thereby understanding the ageing mechanism of the Al-Cu alloy to a wider extent. The validated process sequence in turn resulted in complications where bending of the sheets resulted in cracking. Further investigation was performed and it was found that the BS 2014 alloy has to be bent within two hours of solution annealing in order to have an efficient bending. The results showed that the natural ageing is so rapid in this alloy, which strengthens the material so quickly by the formation of CuAl2 precipitates, thereby, demanding the bending procedure to be performed before the growth of precipitates becomes dominant.

  7. Ejection Performance of Coated Core Pins Intended for Application on High Pressure Die Casting Tools for Aluminium Alloys Processing

    Directory of Open Access Journals (Sweden)

    P. Terek

    2017-09-01

    Full Text Available In high pressure die casting (HPDC process of aluminium alloys cast alloy soldering severely damages tool surfaces. It hampers casting ejection, reduces the casting quality and decreases the overall production efficiency. Thin ceramic PVD (physical vapor deposition coatings applied on tool surfaces successfully reduce these effects. However, their performance is still not recognised for surfaces with various topographies. In this investigation, soldering tendency of Al-Si-Cu alloy toward EN X27CrMoV51 steel, plasma nitrided steel, CrN and TiAlN duplex PVD coatings is evaluated using ejection test. The coatings were prepared to a range of surface roughness and topographies. After the tests sample surfaces were analysed by different microscopy techniques and profilometry. It was found that the ejection performance is independent of the chemical composition of investigated materials. After the ejection, the cast alloy soldering layer was found on surfaces of all tested materials. This built-up layer formed by effects of mechanical soldering, without corrosion reactions. Coated samples displayed a pronounced dependence of ejection force on surface roughness and topography. By decreasing roughness, ejection force increased, which is a consequence of intensified adhesion effects. Presented findings are a novel information important for efficient application of PVD coatings intendent for protection of HPDC tools.

  8. Investigations on Mechanical Behaviour of Micro Graphite Particulates Reinforced Al-7Si Alloy Composites

    Science.gov (United States)

    Nagaraj, N.; Mahendra, K. V.; Nagaral, Madeva

    2018-02-01

    Micro particulates reinforced metal matrix composites are finding wide range of applications in automotive and sports equipment manufacturing industries. In the present study, an attempt has been made to develop Al-7Si-micro graphite particulates reinforced composites by using liquid melt method. 3 and 6 wt. % of micro graphite particulates were added to the Al-7Si base matrix. Microstructural characterization was done by using scanning electron microscope and energy dispersive spectroscope. Mechanical behaviour of Al-7Si-3 and 6 wt. % composites were evaluated as per ASTM standards. Scanning electron micrographs revealed the uniform distribution of micro graphite particulates in the Al-7Si alloy matrix. EDS analysis confirmed the presence of B and C elements in graphite reinforced composites. Further, it was noted that ultimate tensile and yield strength of Al-7Si alloy increased with the addition of 3 and 6wt. % of graphite particulates. Hardness of graphite reinforced composites was lesser than the base matrix.

  9. Improvement of the surface properties of aluminium by the formation of intermetallic phases and metal matrix composites during laser surface alloying

    CSIR Research Space (South Africa)

    Mabhali, Luyolo AB

    2011-05-01

    Full Text Available Aluminium is widely used in industry due to its low cost, light weight and excellent workability, but is lacking in wear resistance and hardness. Laser alloying is used to improve the surface properties, such as hardness, by modifying...

  10. Spectrophotometric determination of titanium with ascorbic acid in aluminium alloys and other materials. Determinacion espectrofotometrica de titanio con acido ascorbico en aleaciones de base aluminio y otros materiales

    Energy Technology Data Exchange (ETDEWEB)

    Bosch Serrat, F. (Departamento de Quimica Analitica. Facultad de Qauimica. Valencia (Spain))

    1994-01-01

    A spectrophotometric determination of titanium with ascorbic acid in aluminium alloys and bauxite is described. The proposed procedures permit to determine levels of titanium down to 5.10 ''3% with a good accuracy and precision. (Author) 13 refs.

  11. Fatigue performance of matching and dissimilar joints in aluminium alloys 5083-H111 and 6061-T651 after fully automatic pulsed GAMW using ER5356 filler wire

    CSIR Research Space (South Africa)

    Mutombo, K

    2010-08-31

    Full Text Available The tensile strength and fatigue properties of Al5083-H111 welded with aluminium-magnesium alloyed ER5356 filler wire appeared similar to those of the base metal. This joint failed in the weld metal as a result of a slight reduction in hardness...

  12. Mechanical properties of aluminium based metal matrix composites reinforced with graphite nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Syed Nasimul, E-mail: syedn@nitrkl.ac.in; Kumar, Lailesh

    2016-06-14

    In this work Al-matrix composites reinforced by exfoliated graphite nanoplatelets (xGnP) is fabricated by powder metallurgy route and their microstructure, mechanical properties and sliding wear behaviour were investigated. Here, xGnP has been synthesized from the thermally exfoliated graphite produced from a graphite intercalation compound (GIC) through rapid evaporation of the intercalant at an elevated temperature. The xGnP synthesized was characterized using scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), x-ray diffraction (XRD), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), differential scanning calorimetry and thermogravimetric analysis (DSC/TGA), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The Al and xGnP powder mixtures were consolidated under a load of 565 MPa followed by sintering at 550 °C for 2 h in an inert atmosphere. Al-1, 2, 3 and 5 wt% xGnP nanocomposites were developed. Results of the wear test show that there was a significant improvement in the wear resistance of the composites up to the addition of 3 wt% of xGnP in the Al matrix. The hardness of the various Al-xGnP composites also shows improvement upto the addition of 1 wt% xGnP beyond which there was a decrease in the hardness of the composites. The tensile strength of the Al-xGnP composites continuously reduced with the addition of xGnP due to the formation of Al{sub 4}C{sub 3} particles at the interface of the Al and xGnP in the composite.

  13. High-temperature brazing of graphite using aluminium as brazing alloy

    International Nuclear Information System (INIS)

    Anikin, L.T.; Kravetskij, G.A.; Dergunova, V.S.

    1977-01-01

    The possibility of enhancing the strength of brazed joints, as well as the effect of the parameters of resistance heating of graphite VPP with PA-4 aluminium on the structure, composition and strength of the joint have been studied. It has been established that brazing of graphite materials, using an aluminium solder will produce a heat-resistant joint of a graphitic composition if the brazing temperature exceeds 2200 deg C. Thermocycling in the course of brazing results in a substantial (1.5-fold) increase in the strength of brazed joints

  14. The structure of high-quality aluminium cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2012-01-01

    Full Text Available In this study presents the analyse of aluminium iron cast structure (as-cast condition which are used in high temperature. While producing the casts of aluminium iron major influence has been preserve the structure of technological process parameters. The addition to Fe-C-Al alloy V, Ti, Cr leads to the improvement of functional and mechanical cast qualities. In this study, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a aluminium cast iron structure and thus improve the production process. V and Ti additions in aluminium cast iron allows to development of FeAl - VC or TiC alloys. In particular, V or Ti contents above 5 wt.% were found to totally eliminate the presence of Al4C3. In addition, preliminary work indicates that the alloy with the FeAl - VC or TiC structure reveals high oxidation resistance. The introduction of 5 wt.% chromium to aluminium cast iron strengthened Al4C3 precipitate. Thus, the resultant alloy can be considered an intermetallic FeAl matrix strengthened by VC and TiC or modified Al4C3 reinforcements.

  15. KevlarTM Fiber-Reinforced Polybenzoxazine Alloys for Ballistic Impact Application

    Directory of Open Access Journals (Sweden)

    Chanchira Jubsilp

    2011-10-01

    Full Text Available A light weight ballistic composites from KevlarTM-reinforcing fiber having polybenzoxazine (BA/urethane prepolymer (PU alloys as a matrix were investigated in this work. The effect of alloy compositions on the ballistic composite properties was determined. The results revealed that the enhancement in the glass transition temperature (Tg of the KevlarTM-reinforced BA/PU composites compared to that of the KevlarTM-reinforced polybenzoxazine composite was observed. The increase of the elastomeric PU content in the BA/PU alloy resulted in samples with tougher characteristics. The storage modulus of the KevlarTM-reinforced BA/PU composites increased with increasing the mass fraction of polybenzoxazine. A ballistic impact test was also performed on the KevlarTM-reinforced BA/PU composites using a 9 mm handgun. It was found that the optimal contents of PU in the BA/PU alloys should be approximately 20wt%. The extent of the delaminated area and interfacial fracture were observed to change with the varied compositions of the matrix alloys. The appropriate thickness of KevlarTM-reinforced 80/20 BA/PU composite panel was 30 plies and 50 plies to resist the penetration from the ballistic impact equivalent to levels II-A and III-A of NIJ standard. The arrangement of composite panels with the higher stiffness panel at the front side also showed the best efficiency of ballistic penetration resistance.

  16. Carbon fiber reinforced magnesium alloy in a Ti-6Al-4V shell

    Directory of Open Access Journals (Sweden)

    Astanin Vasily

    2017-01-01

    Full Text Available Continuous carbon fiber reinforced magnesium alloy pieces in SMC Ti-6Al-4V shell have been fabricated using pressure infiltration. Similar temperatures (~700°C for superplastic formation of the shell and melting of the alloy allow this to be done in one step. The quality of infiltration of the molten alloys is found to be proportional to load. A limiting parameter in increasing the infiltration pressure is the strength of the welded bonds. Structure, fracture parameters and mechanical properties are discussed.

  17. Sintered aluminium powders

    International Nuclear Information System (INIS)

    Stepanova, M.G.; Matveev, B.I.

    1974-01-01

    The mechanical and physical properties of aluminium powder alloys and the various methods employed to produce them are considered. Data are given on the hardening of the alloys SAP and SPAK-4, as well as the powder-alloy system Al-Cr-Zr. (L.M.)

  18. Removal of chromium (VI) from water by micro-alloyed aluminium ...

    African Journals Online (AJOL)

    driniev

    2004-07-03

    Jul 3, 2004 ... aluminium composite (MAlC) under flow conditions ... Behaviour of the composite in water is under significant influence of pH, which affects its efficacy and .... 1.2 x 1.2 mm, ∅ 0.6) with MAl, by means of a special gas burner.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    of 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...

  20. Experimental Study on Dissimilar Friction Stir welding of Aluminium Alloys (5083-H111 and 6082-T6) to investigate the mechanical properties

    Science.gov (United States)

    Kumar, H. M. Anil; Venkata Ramana, V.; Pawar, Mayur

    2018-03-01

    Friction stir welding is an innovative technology in the joining realm of metals and alloys. This technique is highly economical and suitable especially for non ferrous alloys compared to ferrous alloys. It finds many applications in various fields of aeronautics, automobile, ship building industries etc. The paper presents the comparative results of mechanical properties such as tensile strength, microstructure, macro structure and hardness on the similar and dissimilar aluminum alloys AA5083-H111 and AA6082-T6 under certain selected variables - constant tool rotational speed, its tilt angle, welding speed using friction stir welding process. It is observed from the experimental results that joint efficiency of dissimilar aluminium alloys is higher than the similar aluminum alloys.

  1. Design of Laser Welding Parameters for Joining Ti Grade 2 and AW 5754 Aluminium Alloys Using Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Mária Behúlová

    2017-01-01

    Full Text Available Joining of dissimilar Al-Ti alloys is very interesting from the point of view of weight reduction of components and structures in automotive or aerospace industries. In the dependence on cooling rate and chemical composition, rapid solidification of Al-Ti alloys during laser welding can lead to the formation of metastable phases and brittle intermetallic compounds that generally reduce the quality of produced weld joints. The paper deals with design and testing of welding parameters for preparation of weld joints of two sheets with different thicknesses from titanium Grade 2 and AW 5754 aluminium alloy. Temperature fields developed during the formation of Al-Ti butt joints were investigated by numerical simulation in ANSYS software. The influence of laser welding parameters including the laser power and laser beam offset on the temperature distribution and weld joint formation was studied. The results of numerical simulation were verified by experimental temperature measurement during laser beam welding applying the TruDisk 4002 disk laser. The microstructure of produced weld joints was assessed by light microscopy and scanning electron microscopy. EDX analysis was applied to determine the change in chemical composition across weld joints. Mechanical properties of weld joints were evaluated using tensile tests and Vickers microhardness measurements.

  2. Small Crack Growth and Fatigue Life Predictions for High-Strength Aluminium Alloys. Part 1; Experimental and Fracture Mechanics Analysis

    Science.gov (United States)

    Wu, X. R.; Newman, J. C.; Zhao, W.; Swain, M. H.; Ding, C. F.; Phillips, E. P.

    1998-01-01

    The small crack effect was investigated in two high-strength aluminium alloys: 7075-T6 bare and LC9cs clad alloy. Both experimental and analytical investigations were conducted to study crack initiation and growth of small cracks. In the experimental program, fatigue tests, small crack and large crack tests A,ere conducted under constant amplitude and Mini-TWIST spectrum loading conditions. A pronounced small crack effect was observed in both materials, especially for the negative stress ratios. For all loading conditions, most of the fatigue life of the SENT specimens was shown to be crack propagation from initial material defects or from the cladding layer. In the analysis program, three-dimensional finite element and A weight function methods were used to determine stress intensity factors and to develop SIF equations for surface and corner cracks at the notch in the SENT specimens. A plastisity-induced crack-closure model was used to correlate small and large crack data, and to make fatigue life predictions, Predicted crack-growth rates and fatigue lives agreed well with experiments. A total fatigue life prediction method for the aluminum alloys was developed and demonstrated using the crack-closure model.

  3. Overload effects on a ferritic-baintic steel and a cast aluminium alloy: two very different behaviours

    Energy Technology Data Exchange (ETDEWEB)

    Saintier, N. [Arts et Metiers Paris Tech, I2M, UMR CNRS, Universite Bordeaux 1, Talene Cedex (France); El Dsoki, C.; Kaufmann, H.; Sonsino, C.M. [Fraunhofer-Institute for Structural Durability and System Reliability LBF, Darmstadt (Germany); Dumas, C. [RENAULT, Technocentre, Guyancourt Cedex (France); Voellmecke, F.J. [BORBET GmbH, Hallenberg-Hesborn (Germany); Palin-Luc, T.; Bidonard, H.

    2011-10-15

    Load controlled fatigue tests were performed up to 10{sup 7} cycles on flat notched specimens (K{sub t} = 2.5) under constant amplitude and variable amplitude loadings with and without periodical overloads. Two materials are studied: a ferritic-bainitic steel (HE400M steel) and a cast aluminium alloy (AlSi7Mg0.3). These materials have a very different cyclic behaviour: the steel exhibits cyclic strain softening whereas the Al alloy shows cyclic strain hardening. The fatigue tests show that, for the steel, periodical overload applications reduce significantly the fatigue life for fully reversed load ratio (R{sub {sigma}} = -1), while they have no influence under pulsating loading (R{sub {sigma}} = 0). For the Al alloy overloads have an effect (fatigue life decreasing) only for variable amplitude loadings. The detrimental effect of overloads on the steel is due to ratcheting at the notch root which evolution is overload's dependent. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. The effect of dispersoids on the grain refinement mechanisms during deformation of aluminium alloys to ultra-high strains

    International Nuclear Information System (INIS)

    Apps, P.J.; Berta, M.; Prangnell, P.B.

    2005-01-01

    The effect of fine dispersoids on the mechanisms and rate of grain refinement has been investigated during the severe deformation of a model aluminium alloy. A binary Al-0.2Sc alloy, containing coherent Al 3 Sc dispersoids, of ∼20 nm in diameter and ∼100 nm spacing, has been deformed by equal channel angular extrusion to an effective strain of ten. The resulting deformation structures were quantitatively analysed using high-resolution electron backscattered diffraction orientation mapping, and the results have been compared to those obtained from a single-phase Al-0.13Mg alloy, deformed under identical conditions. The presence of fine, non-shearable, dispersoids has been found to homogenise slip, retard the formation of a cellular substructure and inhibit the formation of microshear bands during deformation. These factors combine to reduce the rate of high-angle grain boundary generation at low to medium strains and, hence, retard the formation of a submicron grain structure to higher strains during severe deformation

  5. Formulation of anisotropic Hill criteria for the description of an aluminium alloy behaviour during the channel die compression test

    International Nuclear Information System (INIS)

    Gavrus, A.; Francillette, H.

    2007-01-01

    During the last years the study of the plastic deformation modes and the anisotropic mechanical behaviour of aluminium alloys have been the subject of many investigations. This paper deals with a phenomenological identification of an anisotropic Hill constitutive equation of aluminium AU4G samples using a channel die compression device at room temperature. By considering the different possible orientations of the samples in the channel die device, three initial textures, named ND (normal direction Z), LD (longitudinal direction X) and TD (transverse direction Y), were defined with the corresponding stresses σND, σLD and σTD. To describe the anisotropy of the material, a quadratic Hill criteria is used. An Avrami type equation based on the mixture of the hardening and softening phenomena is used to describe variation of each stress component with the equivalent plastic strain. The identification of the parameters of the law is made using an identification software (OPTPAR) and a good correlation between the experimental stresses and computed ones is obtained. The variation of the Hill parameters with a proposed equivalent strain, describing the deformation history of the material, is analysed. Finally, using the expressions of F, G, H and N, the constitutive equation of the normal anisotropy in the plane XY is obtained

  6. Multi-Objective Optimization of Friction Stir Welding of Aluminium Alloy Using Grey Relation Analysis with Entropy Measurement Method

    Directory of Open Access Journals (Sweden)

    SAURABH KUMAR GUPTA

    2015-01-01

    Full Text Available The present research focus on optimization of Friction Stir Welding (FSW process parameters for joining of AA6061 aluminium alloy using hybrid approach. The FSW process parameters considered are tool rotational speed, welding speed and axial force. The quality characteristics considered are tensile strength (TS and percentage of tensile elongation (TE. Taguchi based experimental design L9 orthogonal array is used for determining the experimental results. The value of weights corresponding to each quality characteristic is determined by using the entropy measurement method so that their importance can be properly explained. Analysis of Variance (ANOVA is used to determine the contribution of FSW process parameters. The confirmation tests also have been done for verifying the results.

  7. Prediction of shear and tensile strength of the diffusion bonded AA5083 and AA7075 aluminium alloy using ANN

    International Nuclear Information System (INIS)

    Sagai Francis Britto, A.; Raj, R. Edwin; Mabel, M. Carolin

    2017-01-01

    Diffusion bonding is a pressure welding technique to establish bonds by inter diffusion of atoms. Bonding characteristics were generated by varying the significant process conditions such as the bonding temperature, the pressing load and the duration of pressure while bonding the aluminium alloys AA5083 and AA7075. Deriving analytical correlation with the process variables to weld strength is quite involved due to the non-linear dependency of the process variables with the mechanical strength of the joints. An arbitrary function approximation mechanism, the artificial neural network (ANN) is therefore employed to develop the models for predicting the mechanical properties of the bonded joints. Back propagation technique, which alters the network weights to minimize the mean square error was used to develop the ANN models. The models were tested, validated and found to be satisfactory with good prediction accuracy.

  8. Electrochemical corrosion characteristics of aluminium alloy 6061 T6 in demineralized water containing 0.1 % chloride ion

    International Nuclear Information System (INIS)

    Zaifol Samsu; Muhammad Daud; Siti Radiah Mohd Kamarudin; Mohd Saari Ripin; Rusni Rejab; Mohd Shariff Sattar

    2012-01-01

    Direct current electrochemical method is one of the techniques has been used to study the corrosion behaviour of metal/alloy in its environment. This paper attempts to investigate the corrosion behaviour of Al 6061 T6 immersed in Reactor TRIGA Mark II pool water containing about 0.1% NaCl content. The result shown that the corrosion rate value of the aluminium 6061 T6 increased with the presence of 0.1 % Ion Chloride content in the demineralized water reactor pool as compared to normal demineralized water. This is due to aggressiveness of chloride ion attack to metal surface. Beside corrosion rate analysis, the further tests such as corrosion behaviour diagram, cyclic polarization have been carried and the results have been reported. (author)

  9. Microstructure, local and global mechanical properties of friction stir welds in aluminium alloy 6005A-T6

    International Nuclear Information System (INIS)

    Simar, A.; Brechet, Y.; Meester, B. de; Denquin, A.; Pardoen, T.

    2008-01-01

    The effect of the welding speed on the microstructure, local and overall mechanical properties of friction stir welded joints has been investigated in the aluminium alloy 6005A-T6. The fine hardening precipitation within the heat-affected zone has been characterized by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). Post-welding heat treatments have been applied to obtain indications on the level of solid solution supersaturation in the as welded state. The local mechanical behaviour was determined using thin specimens extracted from various regions of the weld. The overall properties were measured on samples cut perpendicular to the weld. Specific attention was devoted to the relationship between the local microstructure and local hardening properties in the weakest region, which govern the overall strength and ductility of the welds

  10. The forming of coke by catalytic cracking of black mineral oil by catalysts on the base of activated aluminium alloys

    International Nuclear Information System (INIS)

    Mirzaeva, L.M.; Akhverdiev, R.B.; Aliev, Eh.T.; Gusejnova, A.D.; Gadzhi-Kasumov, V.S.; Akerson, V.I.; Sarmurzina, R.G.

    1995-01-01

    The paper deals with an investigation in coke formation under black mineral oil reactions on oxide catalysts which care based on activated aluminium alloys containing 2-20% of active components of In and Ga. The coke yield is of extreme nature and depends on the content of active components in the catalyst composition. The application of thermogravimetric method shows that the oxidation of coke depositions after black mineral oil cracking proceeds in the same temperature range while after the steam-water treatment of coked catalysts the oxidation of coke deposition proceeds at higher temperatures with different temperature maximums which points to the inhomogeneity of coke depositions. It is shown that the catalyst phase composition changes significantly during the reaction under the effect of reaction mixture. 4 refs., 3 figs

  11. Prediction of shear and tensile strength of the diffusion bonded AA5083 and AA7075 aluminium alloy using ANN

    Energy Technology Data Exchange (ETDEWEB)

    Sagai Francis Britto, A. [Department of Mechanical Engineering, St.Xavier' s Catholic College of Engineering, Nagercoil 629003,Tamil Nadu (India); Raj, R. Edwin, E-mail: redwinraj@gmail.com [Department of Mechanical Engineering, St.Xavier' s Catholic College of Engineering, Nagercoil 629003,Tamil Nadu (India); Mabel, M. Carolin [Department of Electrical and Electronics Engineering, St.Xavier' s Catholic College of Engineering, Nagercoil 629003,Tamil Nadu (India)

    2017-04-24

    Diffusion bonding is a pressure welding technique to establish bonds by inter diffusion of atoms. Bonding characteristics were generated by varying the significant process conditions such as the bonding temperature, the pressing load and the duration of pressure while bonding the aluminium alloys AA5083 and AA7075. Deriving analytical correlation with the process variables to weld strength is quite involved due to the non-linear dependency of the process variables with the mechanical strength of the joints. An arbitrary function approximation mechanism, the artificial neural network (ANN) is therefore employed to develop the models for predicting the mechanical properties of the bonded joints. Back propagation technique, which alters the network weights to minimize the mean square error was used to develop the ANN models. The models were tested, validated and found to be satisfactory with good prediction accuracy.

  12. Characterization of AA7050 aluminium alloy processed by ECAP; Caracterizacao da liga de aluminio AA7050 processada por ECAP

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, K.R.; Guido, V. [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil). Inst. de Pesquisa e Desenvolvimento; Travessa, D.N. [Empresa Brasileira de Aeronautica (EMBRAER), Sao Jose dos Campos, SP (Brazil); Jorge Junior, A.M. [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    The commercial AA7050 aluminium alloy in the solution heat treated condition (W) was processed by ECAP through route A. Two pressing temperatures (room and 150 deg C and velocities (5 and 30mm/min) were used, as well as different number of passes. The effect of such variables on the microstructure evolution was evaluated using optical and transmission electron microscopy with EDX microanalysis, and xray diffraction. It was found that the microstructure has been refined by ECAP, as a result of subgrains formed within deformation bands. ECAP at 150 deg C resulted in intense precipitation of plate like {eta} phase, which evolves to equiaxial morphology as the number of passes increases. (author)

  13. Quantitative TEM study of the precipitation microstructure in aluminium alloy Al(MgSiCu) 6056 T6

    International Nuclear Information System (INIS)

    Delmas, F.; Casanove, M.J.; Lours, P.; Couret, A.; Coujou, A.

    2004-01-01

    The precipitate microstructure in the last-generation aluminium alloy 6056 T6 [AlMgSiCu] is investigated using three complementary techniques of transmission electron microscopy (TEM) with a special focus on the density and volume fraction of strengthening particles. High-resolution TEM allows the identification of the precipitates and the measurement of the precipitate sizes to be performed. Conventional TEM is used to evaluate the number of precipitates in the investigated area as well as their distribution in the matrix. In situ TEM straining, via the analysis of the dislocation slip traces, permits to determine precisely the thickness and the volume of the foil in the region where the precipitates are analysed. Taking into account the shape and the dimensions of precipitates with respect to the foil thickness, a novel methodology for measuring the volume density and the volume fraction of precipitates is proposed

  14. Analysis of Thermo-Elastic Fracture Problem during Aluminium Alloy MIG Welding Using the Extended Finite Element Method

    Directory of Open Access Journals (Sweden)

    Kuanfang He

    2017-01-01

    Full Text Available The thermo-elastic fracture problem and equations are established for aluminium alloy Metal Inert Gas (MIG welding, which include a moving heat source and a thermoelasticity equation with the initial and boundary conditions for a plate structure with a crack. The extended finite element method (XFEM is implemented to solve the thermo-elastic fracture problem of a plate structure with a crack under the effect of a moving heat source. The combination of the experimental measurement and simulation of the welding temperature field is done to verify the model and solution method. The numerical cases of the thermomechanical parameters and stress intensity factors (SIFs of the plate structure in the welding heating and cooling processes are investigated. The research results provide reference data and an approach for the analysis of the thermomechanical characteristics of the welding process.

  15. Determination of Optimal Parameters for Diffusion Bonding of Semi-Solid Casting Aluminium Alloy by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Kaewploy Somsak

    2015-01-01

    Full Text Available Liquid state welding techniques available are prone to gas porosity problems. To avoid this solid state bonding is usually an alternative of preference. Among solid state bonding techniques, diffusion bonding is often employed in aluminium alloy automotive parts welding in order to enhance their mechanical properties. However, there has been no standard procedure nor has there been any definitive criterion for judicious welding parameters setting. It is thus a matter of importance to find the set of optimal parameters for effective diffusion bonding. This work proposes the use of response surface methodology in determining such a set of optimal parameters. Response surface methodology is more efficient in dealing with complex process compared with other techniques available. There are two variations of response surface methodology. The one adopted in this work is the central composite design approach. This is because when the initial upper and lower bounds of the desired parameters are exceeded the central composite design approach is still capable of yielding the optimal values of the parameters that appear to be out of the initially preset range. Results from the experiments show that the pressing pressure and the holding time affect the tensile strength of jointing. The data obtained from the experiment fits well to a quadratic equation with high coefficient of determination (R2 = 94.21%. It is found that the optimal parameters in the process of jointing semi-solid casting aluminium alloy by using diffusion bonding are the pressing pressure of 2.06 MPa and 214 minutes of the holding time in order to achieve the highest tensile strength of 142.65 MPa

  16. Inhibitory effect of konjac glucomanan on pitting corrosion of AA5052 aluminium alloy in NaCl solution.

    Science.gov (United States)

    Zhang, Kegui; Yang, Wenzhong; Xu, Bin; Chen, Yun; Yin, Xiaoshuang; Liu, Ying; Zuo, Huanzhen

    2018-05-01

    A natural carbohydrate polymer, konjac glucomanan, has been extracted from commercial product and studied as a green corrosion inhibitor for AA5052 aluminium alloy in 3.5 wt% NaCl solution by high-performance gel permeation chromatography (GPC), thermo gravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectra, electrochemical measurement and surface characterization techniques. The results of GPC measurements suggest the weight-average molecular weight and the number-average molecular weight of KGM with 98.2% purity are 1.61 × 10 5  g/mol and 1.54 × 10 5  g/mol, respectively. Potentiodynamic polarization curves show konjac glucomanan behaves as a mixed-type inhibitor with dominant anodic effect and that its maximum efficiency at 200 ppm is 94%. Electrochemical impedance spectroscopy (EIS) studies reveal the resistance of oxide film is approximately two orders of magnitude greater than the resistance of adsorbed inhibitor layer and that they both increase with KGM concentration. Moreover, in-situ electrochemical noise (EN) detection demonstrates that the growth and propagation stages of the pitting corrosion germinating on metal surface are blocked by polysaccharide additive, which is confirmed by the surface analysis of aluminium alloy using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and Raman spectroscopy. At last, it is found that the addition of KGM makes it harder for water droplet containing NaCl to wet the metallic substrate. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Effect of weld morphology on mechanical response and failure of friction stir welds in a naturally aged aluminium alloy

    International Nuclear Information System (INIS)

    Imam, Murshid; Biswas, Kajal; Racherla, Vikranth

    2013-01-01

    Highlights: ► Friction stir welds of AA 6063-T4 are obtained using three tool pin profiles. ► Signature of weld defects in mechanical response of welds is investigated. ► Correlation between peak temperatures in HAZs and their hardness is studied. ► Reasons for strengthening of WNZ and softening of HAZs are found using TEM and XRD. ► A FEM model for the weld zone is developed and validated. -- Abstract: Friction stir butt welds in 6063-T4 aluminium alloy were obtained using square and two tapered tool pin profiles. Tensile tests at 0°, 45°, and 90° to the weld line, hardness contours in the weld cross-section, temperatures in the heat affected zones, cross-sectional macrographs, transmission electron micrographs, and X-ray diffraction studies were used to characterize the welds. In transverse weld specimen, tunnel defects appearing at higher weld speeds for tapered pin profiles, were found to result in mechanical instabilities, i.e. sharp drops in load–displacement curves, much before macroscopic necking occured. Further, in comparison to the base metal, a marked reduction in ductility was observed even in transverse specimen with defect free welds. Hardness contours in the weld cross-section suggest that loss in ductility is due to significant softening in heat affected zone on the retreating side. Transmission electron microscopy images demonstrate that while recovery and overaging are responsible for softening in the heat affected zone, grain size refinement from dynamic recrystallization is responsible for strengthening of the weld nugget zone. X-ray diffraction studies in the three weld zones: weld nugget zone, heat affected zone, and the base metal corroborate these findings. A weld zone model, for use in forming simulations on friction stir welded plates of naturally aged aluminium alloys, was proposed based on mechanical characterization tests. The model was validated using finite element analysis.

  18. A statistical analysis on erosion wear behaviour of A356 alloy reinforced with in situ formed TiB2 particles

    International Nuclear Information System (INIS)

    Kumar, S.; Subramanya Sarma, V.; Murty, B.S.

    2008-01-01

    Solid particle erosion wear behaviour of A356 and A356/TiB 2 in situ composites has been studied. A356 alloy reinforced with in situ TiB 2 particles was fabricated by the reaction of halide salts with aluminium melt and the formation of Al 3 Ti brittle phase is completely suppressed. The composites show good grain refinement of α-Al and modification of eutectic Si. These in situ composites show high hardness and better erosion resistance than the base alloy. Though the sizes of in situ formed TiB 2 reinforcement particles are smaller than the erodent SiC particles, TiB 2 particles are able to effectively resist the erodent particles. Design of experiment has been used to run the solid particle erosion experiment. An attempt has also been made to develop a mathematical model by using regression analysis. Analysis of variance (ANOVA) technique is applied to check the validity of the developed model. Student's t-test is utilized to find out the significance of factors. The wear mechanism has been studied by analyzing the surface of the worn specimen using scanning electron microscopy and energy dispersive X-ray microanalysis

  19. Behaviour of smart reinforced concrete beam with super elastic shape memory alloy subjected to monotonic loading

    Science.gov (United States)

    Hamid, Nubailah Abd; Ibrahim, Azmi; Adnan, Azlan; Ismail, Muhammad Hussain

    2018-05-01

    This paper discusses the superelastic behavior of shape memory alloy, NiTi when used as reinforcement in concrete beams. The ability of NiTi to recover and reduce permanent deformations of concrete beams was investigated. Small-scale concrete beams, with NiTi reinforcement were experimentally investigated under monotonic loads. The behaviour of simply supported reinforced concrete (RC) beams hybrid with NiTi rebars and the control beam subject to monotonic loads were experimentally investigated. This paper is to highlight the ability of the SMA bars to recover and reduce permanent deformations of concrete flexural members. The size of the control beam is 125 mm × 270 mm × 1000 mm with 3 numbers of 12 mm diameter bars as main reinforcement for compression and 3 numbers of 12 mm bars as tension or hanger bars while 6 mm diameter at 100 mm c/c used as shear reinforcement bars for control beam respectively. While, the minimal provision of 200mm using the 12.7mm of superelastic Shape Memory Alloys were employed to replace the steel rebar at the critical region of the beam. In conclusion, the contribution of the SMA bar in combination with high-strength steel to the conventional reinforcement showed that the SMA beam has exhibited an improve performance in term of better crack recovery and deformation. Therefore the usage of hybrid NiTi with the steel can substantially diminish the risk of the earthquake and also can reduce the associated cost aftermath.

  20. The speciation of Si and other alloying elements in the oxide surface film of galvanically corroded weld fusion zone of laser welded AA6061 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mujibur Rahman, A.B.M.; Kumar, Sunil [Ian Wark Research Institute, University of South Australia, Mawson Lakes Campus, Mawson Lakes, South Australia 5095 (Australia); Gerson, Andrea R. [Applied Centre for Structural and Synchrotron Studies, University of South Australia, Mawson Lakes Campus, Mawson Lakes, South Australia 5095 (Australia)], E-mail: Andrea.Gerson@unisa.edu.au

    2008-05-15

    It has recently been proposed that on galvanic corrosion of laser weldments of AA6061 aluminium alloy the temporal increase in galvanic corrosion resulted from either the build up of intermetallic phases in the surface oxide layer and/or a significant increase in the surface area of the cathodic weld fusion zone due to the porous nature of the surface layer. This proposition has motivated a comprehensive surface analytical study of the incorporation of alloying elements into the oxide surface film, which is composed predominately of alumina. Si is found to be present as silicate and silicides. The Gibbs free energy of formation, per cation, of silicate is more negative than that for alumina and hence silicate formation is thermodynamically, relatively, favourable. In contrast the Gibbs free energy for oxide formation, per cation, for the other alloying elements is less negative and hence relatively unfavourable compared to the formation of alumina. We propose therefore that Fe, Cu and Cr are present in the metallic form, possibly as silicides, within the oxide surface layer. Magnesium is found to be depleted relative to the weld fusion zone presumably due to dissolution within the electrolyte.

  1. The speciation of Si and other alloying elements in the oxide surface film of galvanically corroded weld fusion zone of laser welded AA6061 aluminium alloy

    International Nuclear Information System (INIS)

    Mujibur Rahman, A.B.M.; Kumar, Sunil; Gerson, Andrea R.

    2008-01-01

    It has recently been proposed that on galvanic corrosion of laser weldments of AA6061 aluminium alloy the temporal increase in galvanic corrosion resulted from either the build up of intermetallic phases in the surface oxide layer and/or a significant increase in the surface area of the cathodic weld fusion zone due to the porous nature of the surface layer. This proposition has motivated a comprehensive surface analytical study of the incorporation of alloying elements into the oxide surface film, which is composed predominately of alumina. Si is found to be present as silicate and silicides. The Gibbs free energy of formation, per cation, of silicate is more negative than that for alumina and hence silicate formation is thermodynamically, relatively, favourable. In contrast the Gibbs free energy for oxide formation, per cation, for the other alloying elements is less negative and hence relatively unfavourable compared to the formation of alumina. We propose therefore that Fe, Cu and Cr are present in the metallic form, possibly as silicides, within the oxide surface layer. Magnesium is found to be depleted relative to the weld fusion zone presumably due to dissolution within the electrolyte

  2. Study of strength properties of semi-finished products from economically alloyed high-strength aluminium-scandium alloys for application in automobile transport and shipbuilding

    Science.gov (United States)

    Baranov, Vladimir; Sidelnikov, Sergey; Zenkin, Evgeny; Frolov, Viktor; Voroshilov, Denis; Yakivyuk, Olga; Konstantinov, Igor; Sokolov, Ruslan; Belokonova, Irina

    2018-04-01

    The results of a study on the strength of rolled products from aluminium alloys doped with scandium under various processing conditions of hot and cold rolling are presented. The regularities of metal flow and the level of strength of deformed semi-finished products from aluminum-scandium alloys are established, depending on the total degree of deformation and the various modes of single reduction during rolling. It is shown that when using one heating of a cast billet to obtain high-quality semi-finished products, the temperature during the rolling process should not be lower than 350-370°, and the total degree of deformation does not exceed 50-60%. It was found that the semi-finished products from alloys with a content of scandium in the range 0.11-0.12% in the deformed state had elevated values of ultimate tensile strength and yield strength of the metal, which allows them to be recommended for industrial production of sheet metal products.

  3. Modern aluminium alloys for aeronautical applications. The role of the Al-Li system

    International Nuclear Information System (INIS)

    Godefroid, L.; Bernardes, A.T.; Bastian, F.L.

    1995-01-01

    A great effort has been made for some Aluminum Industries since the ''80 to develop new alloys with weight reduction, to use in aeronautic industry. The system Al-Li is a good example of this effort, because it presents a low density and a greater stiffness than usual alloys. In this paper we compare some Al-Li alloys with respect to mechanical properties: fracture toughness and resistance to crack propagation on fatigue case. The results are discussed, as well as the nowadays status and perspectives for the use of these alloys. (author)

  4. Strength and Ductility of Forged 1200 Aluminum Alloy Reinforced ...

    African Journals Online (AJOL)

    With 50% reduction and fine-sized steel particles (512μm) in aluminum alloy, tensile strength dropped to 160MPa without significant decrease in ductility (1.7). Microstructure of cast samples show the presence of fine Fe particles at grain boundaries after annealing with most of the particles in solid solution. Al3Fe and AlFeSi ...

  5. Corrosion of aluminium alloy test coupons in water of spent fuel storage pool at RA reactor

    International Nuclear Information System (INIS)

    Pesic, M.; Maksin, T.; Jordanov, G.; Dobrijevic, R.

    2004-12-01

    Study on corrosion of aluminium cladding, of the TVR-S type of enriched uranium spent fuel elements of the research reactor RA in the storage water pool is examined in the framework nr the International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP) 'Corrosion of Research Reactor Clad-Clad Spent Fuel in Water' since 2002. Standard racks with aluminium coupons are exposed to water in the spent fuel pools of the research reactor RA. After predetermined exposure times along with periodic monitoring of the water parameters, the coupons are examined according to the strategy and the protocol supplied by the IAEA. Description of the standard corrosion racks, experimental protocols, test procedures, water quality monitoring and compilation of results of visual examination of corrosion effects are present in this article. (author)

  6. Electrochemical corrosion of carbon-fiber-reinforced plastic-metal electrode couples in corrosion media

    International Nuclear Information System (INIS)

    Chukalovskaya, T.V.; Shcherbakov, A.I.; Chigirinskaya, L.A.; Bandurkin, V.V.; Medova, I.L.; Chukalovskij, P.A.

    1995-01-01

    Polarization diagrams, obtained for carbon-fiber-reinforced plastic(cathode)-metallic material(anode) contact couples are analyzed to predict the corrosion behaviour of some technical metals and alloys (carbon steel, stainless steels, brass, aluminium, titanium) in contact with carbon-fiber-reinforced plastic in differen agressive media (H 2 SO 4 , HCl, H 3 PO 4 , NaOH solutions in wide temperature and concentration range, synthetic seawater at 30 and 50 deg C). The predicted behaviour was supported by direct investigation into carbon-fiber-reinforced plastic-titanium and carbon-fiber-reinforced plastic-aluminium contact couples at different square ratios. 6 refs.; 4 figs

  7. Recycling of Uranium from Uranium-Aluminium alloys by Chlorination with HCl(g)

    OpenAIRE

    MEIER ROLAND; SOUCEK Pavel; MALMBECK Rikard; FANGHAENEL Thomas

    2012-01-01

    Much attention has been paid to the handling of metallic nuclear fuel, which can offer a safe and more secure fuel cycle. To ensure this, it is essential to gain a thorough understanding of the related fundamental processes to scientifically assess the safety aspects. To this aim, a pyrochemical process for the recycling of actinides is being investigated in ITU. It is consisting of anodic dissolution of all actinides to a molten salt bath and electrochemical reduction on solid aluminium cath...

  8. INFLUENCE OF MECHANICAL ALLOYING AND LEAD CONTENT ON MICROSTRUCTURE, HARDNESS AND TRIBOLOGICAL BEHAVIOR OF 6061 ALUMINIUM ALLOYS

    Directory of Open Access Journals (Sweden)

    M. Paidpilli

    2017-03-01

    Full Text Available In the present work, one batch of prealloyed 6061Al powder was processed by mixing and another one was ball milled with varying amount of lead content (0-15 vol. %. These powders were compacted at 300MPa and sintered at 590˚C under N2. The instrumented hardness and the young’s modulus of as-sintered 6061Al-Pb alloys were examined as a function of lead content and processing route. The wear test under dry sliding condition has been performed at varying loads (10-40 N using pin-on-disc tribometer. The microstructure and worn surfaces have been investigated using SEM to evaluate the change in topographical features due to mechanical alloying and lead content. The mechanically alloyed materials showed improved wear characteristics as compared to as-mixed counterpart alloys. Delamination of 6061Al-Pb alloys decreases up to an optimum lead composition in both as-mixed and ball-milled 6061Al-Pb alloys. The results indicated minimum wear rate for as-mixed and ball-milled 6061Al alloy at 5 and 10 vol. % Pb, respectively.

  9. Method of processing titanium aluminium alloys modified by chromium and niobium

    International Nuclear Information System (INIS)

    Huang, S.C.

    1991-01-01

    This patent describes the method of processing a TiAl base alloy to impart desirable strength and ductility properties which providing a melt of the TiAl base alloy having the formula Ti 51-42 Al 46-50 Cr 1-3 Nb 1-5

  10. Constitution, structure and magnetic properties of some rare-earth - cobalt-aluminium alloys

    International Nuclear Information System (INIS)

    Evans, J.; Harris, I.R.

    1982-01-01

    The constitution and structure of the alloys represented by the formulae Cesub(1-x)Alsub(x)Co 5 and Prsub(1-x)Alsub(x)Co 5 (where 0 = 5 produces a mixture of the 1:5 and 2:17 phases based on CeCo 5 and Ce 2 Co 17 ; there are two variations of the 2:17 phase which are isostructural with the hexagonal Th 2 Ni 17 -type and rhombohedral Th 2 Zn 17 -type phases. At the composition Cesub(0.76)Alsub(0.24)Co 5 (4 at % Al) the alloy consists only of the 2:17-type phases and metallographically the alloy is one phase in appearance. Further substitution of Al results in the precipitation of an fcc phase, based on the Co-Al solid solution, in the 2:17 matrix. The crystal structures of the Prsub(1-x)Alsub(x)Co 5 alloys are very similar to those of the equivalent cerium alloys. The metallographic structures of the Pr alloys in the composition range 1 to 3 at % Al show significant differences from the corresponding Ce alloys. Determination of the Curie temperatures of the Rsub(1-x)Alsub(x)Co 5 alloys (R = Ce and Pr) in the composition range 0 = 5 and PrCo 5 phases. (author)

  11. Influence of reinforcement grade and matrix composition on corrosion resistance of cast aluminium matrix composites (A3xx.x/SiCp) in a humid environment

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, A.; Viejo, F.; Carboneras, M. [Departamento de Ciencia de Materiales, Facultad de Quimica Universidad Complutense, 28040, Madrid (Spain); Merino, M.C. [Departamento de Ciencia de Materiales, Facultad de Quimica Universidad Complutense, 28040, Madrid (Spain); Departamento de Tecnologia Industrial, Universidad Alfonso X El Sabio, 28691, Villanueva de la Canada, Madrid (Spain); Lopez, M.D. [Escuela Superior de Ciencias Experimentales y Tecnologia, Universidad Rey Juan Carlos, 28931, Mostoles, Madrid (Spain); Merino, S. [Departamento de Tecnologia Industrial, Universidad Alfonso X El Sabio, 28691, Villanueva de la Canada, Madrid (Spain)

    2003-05-01

    A study of the influence of the silicon carbide (SiC{sub p}) proportion and the matrix concentration of four aluminium metal matrix composites (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p) exposed to high relative humid environment was carried out under simulation in a climatic chamber. The matrix of A360/SiC/xxp composites was virtually free of copper while the A380/SiC/xxp matrix contained 3.13-3.45wt% Cu and 1.39-1.44wt% Ni. The kinetics of the corrosion process was studied on the basis of gravimetric tests. The nature of corrosion products was analysed by Scanning Electron Microscopy (SEM) and Low Angle X-Ray Diffraction (XRD) before and after accelerated testing to determine the influence of microstructural changes on corrosion behaviour during exposure to the corrosive environment. The corrosion damage to Al/SiCp composites was low at 80% Relative Humidity (RH) and increased with temperature, SiCp proportion, relative humidity and Cu matrix concentration. The main attack nucleation sites were the interface region between the matrix and the reinforcement particles. The corrosion process was influenced more by the concentration of alloy elements in the matrix than by the proportion of SiCp reinforcement. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [German] Eine Studie zum Einfluss des Siliziumkarbidanteils (SiCp) und der Zusammensetzung des Grundwerkstoffs von vier Aluminiummatrixverbundwerkstoffen (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p), die in Umgebungen mit relativ hoher Feuchtigkeit ausgelagert waren, wurde unter simulierten Bedingungen in einer Klimakammer durchgefuehrt. Die Matrix des A360/SiC/xxp-Verbundwerkstoffs war praktisch Kupfer-frei waehrend die A380/SiC/xxp Matrix 3,13-3,45 Gew.-% Cu und 1,39-1,44 Gew.-% Ni enthielt. Die Kinetik des Korrosionsprozesses wurde auf der Basis von gravimetrischen Messungen studiert. Die Beschaffenheit der Korrosionsprodukte wurde mittelt REM-Untersuchungen und

  12. Recovery in aluminium

    DEFF Research Database (Denmark)

    Gundlach, Carsten

    2006-01-01

    In the present thesis the development of a unique experimental method for volume characterisation of individual embedded crystallites down to a radius of 150 nm is presented. This method is applied to in-situ studies of recovery in aluminium. The method is an extension of 3DXRD microscopy, an X...... are represented as strings. To identify the strings a combination of a 5D connected component type algorithm and multi-peak fitting was found to be superior. The first use of the method was a study of recovery of a deformed aluminium alloy (AA1050). The aluminium alloy was deformed by cold rolling to a thickness...

  13. La2O3-reinforced W and W-V alloys produced by hot isostatic pressing

    International Nuclear Information System (INIS)

    Munoz, A.; Monge, M.A.; Savoini, B.; Rabanal, M.E.; Garces, G.; Pareja, R.

    2011-01-01

    W and W-V alloys reinforced with La 2 O 3 particles have been produced by MA and subsequent HIP at 1573 K and 195 MPa. The microstructure of the consolidated alloys has been characterized by scanning electron microscopy, energy dispersive spectroscopy analyses and X-ray diffraction. The mechanical properties were studied by nanoindentation measurements. The results show that practically full dense billets of W-V, W-V-La 2 O 3 and W-La 2 O 3 alloys can be produced. The microstructure analysis has shown that islands of V are present in W-V and W-V-1La 2 O 3 alloys. In W-1La 2 O 3 islands of La 2 O 3 are also present. The nanohardness of the W matrix increases with the addition of V, while decreases with the addition of La 2 O 3 .

  14. Investigations into the corrosion resistance of copper aluminium alloys. Effect of phosphorus as corrosion resistant third alloying element in the ternary system CuAl20P1

    International Nuclear Information System (INIS)

    Allwardt, A.

    1997-01-01

    The effect of phosphorus on the corrosion resistance of Al-bronzes is studied in detail in this work. A literature review showed that there are a lot of things known about the microstructure and the mechanical properties of Al-bronzes. In spite of their corrosion resistance the corrosion properties and the structure of the protective oxide films of Al-bronzes were seldom a matter of interest. Systematic studies of the influence of different alloying elements on the oxide film and the corrosion properties are rare. Therefore, it is not possible to predict the corrosion resistance of Al-bronzes, made by alloying particular elements. The high corrosion resistance of the new alloy CuAl 20 P 1 was the reason to investigate the influence of phosphorus on the corrosion properties of Al-bronzes in more detail. A systematic study of the microstructure and the corrosion properties of Cu, CuP x , CuAl 20 and CuAl 20 P x offers an insight into the effect of aluminium and phosphorus on the formation of the oxide film on Al-bronzes. It was found that there exists a critical amount of 1 at.-% of phosphorus. Above and below this amount the corrosion resistance becomes worse. This behaviour could be explained by XPS-and electrochemical measurements. Although there are still some questions about the influence of phosphorus on the corrosion resistance of Al-bronzes, this work has produced some important results, which in the future may be helpful to develop new high corrosion resistant Al-bronzes more efficiently: - on clean surface Al-bronze, the oxidation of Al and Cu takes place simultaneously, - Al promotes the formation of Cu 2 O but impedes the formation of Cu(II)-oxide/-hydride in neutral solutions, - P impedes the formation of Cu 2 O and as a consequence promotes the formation of aluminium oxide. This results in a higher amount of Al in the oxide film on the surface of the alloy, which leads to a better corrosion resistance. (author) figs., tabs., 106 refs

  15. Evaluation of mechanical properties of aluminium alloy–alumina–boron carbide metal matrix composites

    International Nuclear Information System (INIS)

    Vijaya Ramnath, B.; Elanchezhian, C.; Jaivignesh, M.; Rajesh, S.; Parswajinan, C.; Siddique Ahmed Ghias, A.

    2014-01-01

    Highlights: • Fabrication of MMC with aluminium alloy–alumina–boron carbide is done. • Different proportions of reinforcements are added. • The effects of varying proportions are studied. • Investigation on mechanical properties above composites is performed. • Failure morphology analysis is done using SEM. - Abstract: This paper deals with the fabrication and mechanical investigation of aluminium alloy, alumina (Al 2 O 3 ) and boron carbide metal matrix composites. Aluminium is the matrix metal having properties like light weight, high strength and ease of machinability. Alumina which has better wear resistance, high strength, hardness and boron carbide which has excellent hardness and fracture toughness are added as reinforcements. Here, the fabrication is done by stir casting which involves mixing the required quantities of additives into stirred molten aluminium. After solidification, the samples are prepared and tested to find the various mechanical properties like tensile, flexural, impact and hardness. The internal structure of the composite is observed using Scanning Electron Microscope (SEM)

  16. Effect of nano-hydroxyapatite reinforcement in mechanically alloyed NiTi composites for biomedical implant

    International Nuclear Information System (INIS)

    Akmal, Muhammad; Raza, Ahmad; Khan, Muhammad Mudasser; Khan, M. Imran; Hussain, Muhammad Asif

    2016-01-01

    Equi-atomic NiTi alloy composites reinforced with 0, 2, 4 and 6 vol.% nano-hydroxyapatite (HA) were successfully synthesized using pressureless sintering. Pure Ni and Ti elements were ball milled for 10 h in order to produce a mechanically alloyed equi-atomic NiTi alloy (MA-NiTi). Mechanically alloyed NiTi and HA powders were blended, compacted and then sintered for 3 h at 1325 K. The sintered density varied inversely with volume percent of HA reinforcement. The X-Ray diffraction spectra and SEM images showed the formation of multiple phases like NiTi, NiTi 2 , Ni 3 Ti, and Ni 4 Ti 3 . The back scattered-SEM image analysis confirmed the presence of Ni-rich and Ti-rich phases with increasing HA content. The 6 vol.% HA reinforced composite showed Ni 3 Ti as the major phase having the highest hardness value which can be attributed to the presence of relatively harder phases along with higher HA content as a reinforcement. The composite of MA-NiTi with 2 vol.% HA manifested the most desirable results in the form of better sintering density mainly due to the minute decomposition of NiTi into other phases. Therefore, the 2 vol.% reinforced MA-NiTi composite can be exploited as a novel material for manufacturing biomedical implants. - Highlights: • NiTi-HA composites were synthesized using powder metallurgy route. • New phases such as NiTi 2 , Ni 3 Ti and Ni 4 Ti 3 were observed for sintered composites. • Mechanical properties enhanced with the increasing content of HA and new phases. • No martensitic transformation was observed for all composites by DSC analysis. • 2 vol.% HA composite is a novel candidate for biomedical implants.

  17. Effect of nano-hydroxyapatite reinforcement in mechanically alloyed NiTi composites for biomedical implant

    Energy Technology Data Exchange (ETDEWEB)

    Akmal, Muhammad, E-mail: muhammad.akmal@giki.edu.pk [Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640 (Pakistan); Raza, Ahmad, E-mail: ahmadrazac@yahoo.com [Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640 (Pakistan); Khan, Muhammad Mudasser; Khan, M. Imran [Faculty of Materials and Chemical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640 (Pakistan); Hussain, Muhammad Asif [Department of Chemical Engineering, Kangwon National University, Samcheok, 25913 (Korea, Republic of)

    2016-11-01

    Equi-atomic NiTi alloy composites reinforced with 0, 2, 4 and 6 vol.% nano-hydroxyapatite (HA) were successfully synthesized using pressureless sintering. Pure Ni and Ti elements were ball milled for 10 h in order to produce a mechanically alloyed equi-atomic NiTi alloy (MA-NiTi). Mechanically alloyed NiTi and HA powders were blended, compacted and then sintered for 3 h at 1325 K. The sintered density varied inversely with volume percent of HA reinforcement. The X-Ray diffraction spectra and SEM images showed the formation of multiple phases like NiTi, NiTi{sub 2}, Ni{sub 3}Ti, and Ni{sub 4}Ti{sub 3}. The back scattered-SEM image analysis confirmed the presence of Ni-rich and Ti-rich phases with increasing HA content. The 6 vol.% HA reinforced composite showed Ni{sub 3}Ti as the major phase having the highest hardness value which can be attributed to the presence of relatively harder phases along with higher HA content as a reinforcement. The composite of MA-NiTi with 2 vol.% HA manifested the most desirable results in the form of better sintering density mainly due to the minute decomposition of NiTi into other phases. Therefore, the 2 vol.% reinforced MA-NiTi composite can be exploited as a novel material for manufacturing biomedical implants. - Highlights: • NiTi-HA composites were synthesized using powder metallurgy route. • New phases such as NiTi{sub 2}, Ni{sub 3}Ti and Ni{sub 4}Ti{sub 3} were observed for sintered composites. • Mechanical properties enhanced with the increasing content of HA and new phases. • No martensitic transformation was observed for all composites by DSC analysis. • 2 vol.% HA composite is a novel candidate for biomedical implants.

  18. Microstructure and ductility of Fe28Cr16Co alloy with additions of silicon, molybdenum, titanium and aluminium

    International Nuclear Information System (INIS)

    Vodopivec, F.; Zvokelj, J.; Breskvar, B.; Gnidovec, D.; Rodic, A.; Torkar, M.

    1994-01-01

    The microstructure of several alloys with base composition Fe28Cr16Co and addition up to 1.5% silicon, 0.32% titanium, 2.34% molybdenum and 1% aluminium was investigated in the temperature range 500 to 1250 C by optical microscopy, hardness measurements and dilatometry. Also, ductility and wire drawing tests were carried out on some alloys. The addition of silicon, titanium, molybdenum or 0.13% Al does not prevent the formation of γ phase up to the temperature 1250 C and the formation of phase σ in the temperature range 700 to approximately 1000 C. The addition of 1% Al prevents the formation of phase σ and shifts the temperature of formation of phase γ to 1158 C. The addition of different elements does not affect significantly the spinodal decomposition of phase α. At increased temperature an interval of sufficient ductility for deformation by wire drawing was established. The ductility was greatly improved if the microstructure consisted of small inclusions of phase γ in a matrix of phase α, probably because the deformation by twinning was hindered. However, insufficient magnetic properties were obtained also after 80% of deformation. (orig.)

  19. Influence of Welding Process and Post Weld Heat Treatment on Microstructure and Pitting Corrosion Behavior of Dissimilar Aluminium Alloy Welds

    Science.gov (United States)

    Venkata Ramana, V. S. N.; Mohammed, Raffi; Madhusudhan Reddy, G.; Srinivasa Rao, K.

    2018-03-01

    Welding of dissimilar Aluminum alloy welds is becoming important in aerospace, shipbuilding and defence applications. In the present work, an attempt has been made to weld dissimilar aluminium alloys using conventional gas tungsten arc welding (GTAW) and friction stir welding (FSW) processes. An attempt was also made to study the effect of post weld heat treatment (T4 condition) on microstructure and pitting corrosion behaviour of these welds. Results of the present investigation established the differences in microstructures of the base metals in T4 condition and in annealed conditions. It is evident that the thickness of the PMZ is relatively more on AA2014 side than that of AA6061 side. In FS welds, lamellar like shear bands are well noticed on the top of the stir zone. The concentration profile of dissimilar friction stir weld in T4 condition revealed that no diffusion has taken place at the interface. Poor Hardness is observed in all regions of FS welds compared to that of GTA welds. Pitting corrosion resistance of the dissimilar FS welds in all regions was improved by post weld heat treatment.

  20. Enhancing elevated temperature strength of copper containing aluminium alloys by forming L12 Al3Zr precipitates and nucleating θ″ precipitates on them.

    Science.gov (United States)

    Kumar Makineni, Surendra; Sugathan, Sandeep; Meher, Subhashish; Banerjee, Rajarshi; Bhattacharya, Saswata; Kumar, Subodh; Chattopadhyay, Kamanio

    2017-09-11

    Strengthening by precipitation of second phase is the guiding principle for the development of a host of high strength structural alloys, in particular, aluminium alloys for transportation sector. Higher efficiency and lower emission demands use of alloys at higher operating temperatures (200 °C-250 °C) and stresses, especially in applications for engine parts. Unfortunately, most of the precipitation hardened aluminium alloys that are currently available can withstand maximum temperatures ranging from 150-200 °C. This limit is set by the onset of the rapid coarsening of the precipitates and consequent loss of mechanical properties. In this communication, we present a new approach in designing an Al-based alloy through solid state precipitation route that provides a synergistic coupling of two different types of precipitates that has enabled us to develop coarsening resistant high-temperature alloys that are stable in the temperature range of 250-300 °C with strength in excess of 260 MPa at 250 °C.

  1. Comparative Investigation on Modal analysis of LM25 Aluminium alloy with other Aluminim alloys using Finite element analysis software

    Science.gov (United States)

    Arunkumar, S.; Baskaralal, V. P. M.; Muthuraman, V.

    2017-03-01

    The rudimentary steps of the modal analysis and simulation are carried out. The modal analysis is carried out on the different Aluminum Alloys cantilever beam. The cantilever beam is designed in the graphical environment of the ANSYS. The cantilever beam was fine-tuned on one end with all degree of liberation on this end were taken, beam cannot move and rotate. Mode shapes and natural frequencies are premeditated in platforms ANSYS with arithmetical formulation of the direct solver including the block Lanczos method. Aluminum alloys are widely utilized in much application due to their estimable weight to vigor property. Many examination works have been distributed out to make developments the mechanical properties of aluminum alloys. The composition of alloying elements plays a consequential role in deciding the properties of an alloy. In this study a numerical analysis implement i.e., finite element analysis (FEA) is utilized. The work obtainable in this paper is aimed at the study of effect of modal analysis of different aluminum alloys. The modeling and analysis is carried out utilizing ANSYS FEA software. A modal analysis is carried out to understand the modes of frequency demeanor of the material considered. The modal analysis play a vital role in the design of components subjected to high vibration.

  2. MATERIAL CHOICE AND BLANKS OPERATION TECHNOLOGY OF AK6 ALUMINIUM ALLOY

    Directory of Open Access Journals (Sweden)

    N. YE. Kalinina

    2014-03-01

    Full Text Available Purpose. Justification of the material and heat treatment method of aluminum alloy for the manufacturing of parts, type «plate» based on the results of microstructure and mechanical properties research; development of technological process of blanks operation of AK6 aluminum alloy. Methodology. Powdered alloy based on aluminum type AK6 was the research material. Finished forgings with the size 2520×1520×65 mm were obtained as a result of the preparation and forging of the blanks. After mechanical treatment of the blanks they were exposed to thermal processing and milling. Structure of the metal was examined under light microscope MIM-8M. Brinell hardness was used as the strength alloy characteristic. Findings. Influence analysis of alloy elements on the structure of deformable aluminum alloys was carried out. Research of influence of heat treatment modes on structure and properties of the AK6 alloy were performed. The improved technological process, which made it possible to obtain the item with the improved structure and properties and lower costs is offered. Originality. The samples of AK6 powdered alloy on fire resistance were tested. It is established that under heating of an example in the oxidative flame, it does not ignite to a temperature of 705 °C. The cause of high fire resistance of AK6 alloy samples was found, it is connected with the presence in the material the evenly distributed, small oxide inclusions and amorphous oxide film on the surface. Practical value. Hard conditions of work (corrosion in marine and industrial atmosphere, static and shock loads, cyclic temperature allow the use of the item in various designs.

  3. Influence of Various Process Parameters on the Density of Sintered Aluminium Alloys

    Directory of Open Access Journals (Sweden)

    Mateusz Laska

    2012-01-01

    Full Text Available This paper presents the results of density measurements carried out on Alumix sintered parts. ECKA Alumix aluminium powders were used because of their wide application in the powder metallurgy industry. The compacts were produced using a wide range of compaction pressures for three different chemical compositions. The compacts were then sintered under a pure dry nitrogen atmosphere at three different temperatures. The heating and cooling rates were the same throughout the entire test. The results showed that the green density increases with compaction pressure, but that sintered density is independent of green density (compaction pressure for each sintering temperature.

  4. Strain hardening of aluminium alloy 3004 in the deep drawing and ironing processes

    International Nuclear Information System (INIS)

    Courbon, J.; Duval, J.L.

    1993-01-01

    The evolution of material hardening resulting from the canmaking operations on aluminium beverage cans has been investigated. Tensile tests in cup walls revealed that deep drawing induced softening in the hoop direction and hardening in the meridian direction. This anisotropy is retained in the ironing operation. Changes in strain path on a heavily cold-rolled material probably cause such a complex behaviour. To determine hardening laws for deep drawing, simple shear tests were thus performed because of the strain path similarity. They allowed to determine hardening laws over larger strains than tension could reach and revealed a saturation of stress. Altogether they proved adapted to the understanding of deep drawing. (orig.)

  5. XPS Study of Chemical Changes on the La/Ce Treated Surface of A361 Aluminium Alloy Exposed to Air at Temperatures up to 500∘C

    Directory of Open Access Journals (Sweden)

    A. Pardo

    2009-01-01

    Full Text Available The chemical changes that take place on the rare earth treated surface of the A361 aluminium alloy exposed to air at temperatures between 100 and 500∘C have been examined using X-ray photoelectron spectroscopy (XPS. The most notable features discussed in this work are the disappearance of Mg and Si signals at the tested temperatures and disappearance of the Ce signal at temperatures of 400–500∘C. The biphasic microstructure of the A361 alloy, constituted by close to 12 wt% Si and the Al matrix, plays an important role in many of the results obtained. The notable growth of aluminium oxide across the conversion coating in the case of the Ce-treated surface is related to the structural transformation experienced by the cerium oxide coating at 400–500∘C.

  6. Effect of post weld heat treatment on tensile properties and microstructure characteristics of friction stir welded armour grade AA7075-T651 aluminium alloy

    Directory of Open Access Journals (Sweden)

    P. Sivaraj

    2014-03-01

    Full Text Available This paper reports the effects of post weld heat treatments, namely artificial ageing and solution treatment followed by artificial ageing, on microstructure and mechanical properties of 12 mm thick friction stir welded joints of precipitation hardenable high strength armour grade AA7075-T651 aluminium alloy. The tensile properties, such as yield strength, tensile strength, elongation and notch tensile strength, are evaluated and correlated with the microhardness and microstructural features. The scanning electron microscope is used to characterie the fracture surfaces. The solution treatment followed by ageing heat treatment cycle is found to be marginally beneficial in improving the tensile properties of friction stir welds of AA7075-T651 aluminium alloy.

  7. Reducing non value adding aluminium alloy in production of parts through high pressure die casting

    CSIR Research Space (South Africa)

    Pereira, MFVT

    2010-10-01

    Full Text Available in the cast part feed system, including overflows. CSIR intends using the results of this research for further development and application of high temperature die construction materials in high pressure die casting processes of light metal alloys...

  8. Scanning Precession Electron Diffraction Study of 2xxx Series Aluminium Alloys Exhibiting Several Coexisting Strengthening Phases

    OpenAIRE

    Sunde, Jonas Kristoffer

    2016-01-01

    Throughout this thesis, scanning precession electron diffraction is applied to heat-treated Al-Cu-Li and Al-Mg-Cu-Ag alloys, shedding light on the distribution of phases present and the complex interplay between these microstructural features. The employed technique yielded high quality data sets, which through subsequent data processing enabled a detailed phase mapping of these multi-component Al alloys. Among the main results presented, are virtual dark field images highlighting all separat...

  9. Effect of Shortened Heat Treatment on the Hardness and Microstructure of 320.0 Aluminium Alloy

    Directory of Open Access Journals (Sweden)

    Pezda J.

    2014-06-01

    Full Text Available Improvement of Al-Si alloys properties in scope of classic method is connected with change of Si precipitations morphology through: using modification of the alloy, maintaining suitable temperature of overheating and pouring process, as well as perfection of heat treatment methods. Growing requirements of the market make it necessary to search after such procedures, which would quickly deliver positive results with simultaneous consideration of economic aspects. Presented in the paper shortened heat treatment with soaking of the alloy at temperature near temperature of solidus could be assumed as the method in the above mentioned understanding of the problem. Such treatment consists in soaking of the alloy to temperature of solutioning, keeping in such temperature, and next, quick quenching in water (20 °C followed by artificial ageing. Temperature ranges of solutioning and ageing treatments implemented in the adopted testing plan were based on analysis of recorded curves from the ATD method. Obtained results relate to dependencies and spatial diagrams describing effect of parameters of the solutioning and ageing treatments on HB hardness of the investigated alloy and change of its microstructure. Performed shortened heat treatment results in precipitation hardening of the investigated 320.0 alloy, what according to expectations produces increased hardness of the material.

  10. Effect of post weld heat treatment on tensile properties and microstructure characteristics of friction stir welded armour grade AA7075-T651 aluminium alloy

    OpenAIRE

    Sivaraj, P.; Kanagarajan, D.; Balasubramanian, V.

    2014-01-01

    This paper reports the effects of post weld heat treatments, namely artificial ageing and solution treatment followed by artificial ageing, on microstructure and mechanical properties of 12 mm thick friction stir welded joints of precipitation hardenable high strength armour grade AA7075-T651 aluminium alloy. The tensile properties, such as yield strength, tensile strength, elongation and notch tensile strength, are evaluated and correlated with the microhardness and microstructural features....

  11. APPLICATION OF CHEMICAL PRE-TREATMENT ON THE POLISHED SURFACE OF ALUMINIUM ALLOYS

    Directory of Open Access Journals (Sweden)

    Pavel Kraus

    2016-12-01

    Full Text Available This paper reports the preparation and characterization of thin transparent nanolayers with phase composition ZrF4 and different modification of SiO2 with special focus on affecting the surface roughness of the material and the way of exclusion of the thin nanolayer on the surface of the polished aluminium material. The thin nanolayer was prepared by the sol-gel method. The final treatment based on PTFE was applied on the surface of some samples. This treatment is suitable for increasing wear resistance. The films were characterized with help of SEM microscopy and EDS analysis. The surface roughness was measured with classical surface roughness tester. The results on this theme have already published but not on the polished surface of the aluminium material. The results from the experiment show the problems with application of these nanolayers because a cracks were found on the surface of the material and deformations of the layer after application of the PTFE final layer. The surface layer formation is discussed.

  12. Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant.

    Science.gov (United States)

    Petersen, Richard C

    2011-05-03

    Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats revealed far-reaching significant osseoconductivity increases from bisphenyl-polymer/carbon-fiber composites when compared to state-of-the-art titanium-6-4 alloy controls. Midtibial percent bone area measured from the implant surface increased when comparing the titanium alloy to the polymer composite from 10.5% to 41.6% at 0.8 mm, P engineering potential.

  13. Optimization of the composition and structure of heat-resistant casting aluminium alloys with additions of cerium, iron, nickel and zirconium

    International Nuclear Information System (INIS)

    Belov, N.A.; Lavrishchev, Yu.V.

    2000-01-01

    A study is made of the effect of composition and structure on mechanical properties of cast alloys of the Al-Ce-Ni-Fe-Zr system in which binary and ternary eutectics with participation of low alloyed aluminium solid solution and Al 4 Ce, Al 3 Ni and Al 9 FeNi phases are crystallized. It is found that microhardness of eutectics is heavily dependent on the volume fraction of aluminides and their dispersivity. It was shown that essential hardening of aluminium matrix can be achieved at the cost of zirconium additive in quantity of 0.6 % when using two-stage manufacturing operation. Experimental compositions of Al-10 % Ce-5% Ni-0.6 % Zr and Al-1.5 % Fe-1.5 % Ni-0.6 % Zr on the basis of ternary and binary eutectics respectively as billets essentially exceed industrial heat-resistant cast aluminium alloys AK12MMgN and AM5 as to a set of room and high-temperature mechanical properties and hot brittleness index [ru

  14. Effect of Al–5Ti–1B grain refiner on the microstructure, mechanical properties and acoustic emission characteristics of Al5052 aluminium alloy

    OpenAIRE

    Pattnaik, Amulya Bihari; Das, Satyabrat; Jha, Bharat Bhushan; Prasanth, Nedumbilly

    2015-01-01

    In the present investigation, the effect of Al–5Ti–1B grain refiner on the microstructure, mechanical properties and acoustic emission characteristics of Al 5052 aluminium alloy have been studied. Microstructural analysis showed the presence of primary α solid solution. No Al–Mg phase was found to be formed due to the presence of magnesium in the solid solution. The results indicated that the addition of Al–5Ti–1B grain refiner into the alloy caused a significant improvement in ultimate tensi...

  15. Effect of 1.0% Ni on high-temperature impression creep and hardness of recycled aluminium alloy with high Fe content

    Science.gov (United States)

    Faisal, M.; Mazni, Noor; Prasada Rao, A. K.

    2018-03-01

    Reported work focusses on the effect of 1.0% Ni addition on the microstructure, high- temperature impression creep and thereby the hardness of recycled Al-alloy containing >2wt% Fe, obtained from automotive scrap. Present studies have shown that the addition of 1.0% Ni have supress the formation of α-phase (Al5FeSi) by supressing the peritectic transformation of β-phase (Al8Fe2Si). Such suppression is found to improve the hardness and high-temperature impression creep of the recycled aluminium alloy.

  16. Critical Speed Analysis of Fibre Reinforced Composite Rotor Embedded with Shape Memory Alloy Wires

    OpenAIRE

    Gupta, K.

    2000-01-01

    In the present analysis, the fundamental natural frequency of a Jeffcott and a two-mass rotor with fibre reinforced composite shaft embedded with shape memory alloy (SMA) wires is evaluated by Rayleigh's procedure. The flexibility of rotor supports is taken into account. The effect of three factors, either singly or in combination with each other, on rotor critical speed is studied. The three factors are: (i) increase in Young's modulus of SMA (NITINOL) wires when activated, (ii) tension in w...

  17. Determination of crystalline texture in aluminium - uranium alloys by neutron diffraction

    International Nuclear Information System (INIS)

    Azevedo, A.M.V. de.

    1978-01-01

    Textures of hot-rolled aluminum-uranium alloys and of aluminum were determined by neutron diffraction. Sheets of alloys containing 8.0, 21.5 and 23.7 wt pct U, as well as pure aluminum, were obtained in a stepped rolling process, 15% reduction each step, 75% total reduction. During the rolling the temperature was 600 0 C. Alloys with low uranium contents are two phase systems in which an intermetallic compound UAl 4 , orthorhombic, is dispersed in a pure aluminum matrix. The addition of a few percent of Si in such alloys leads to the formation of UAl 3 , simple cubic, instead of UAl 4 . The Al -- 23.7 wt pct U alloy was prepared with 2,2 wt pct of Si. The results indicate that the texture of the matrix is more dependent on the uranium concentration than on the texture of the intermetallic phases. An improvement in the technique applied to texture measurements by using a sample fully bathed in the neutron beam is also presented. The method takes advantage of the low neutron absorption of the studied materials as well as of the neglibible variation in the multiple scattering which occurs in a conveniently shaped sample having a weakly developed texture. (Author) [pt

  18. Biochemical analysis of the Hormoconis resinae fungal mycelium in the corrosion of aeronautical aluminium alloys

    International Nuclear Information System (INIS)

    Araya, R.; Bobadilla, C.; Vera, R.; Rosales, B. M.

    2007-01-01

    Biochemical analyses of the Hormoconis resinae fungal mycelium would explain behaviour differences of corrosive and non-corrosive strains of Al and its aeronautical alloys. In previous works its aggressiveness had been studied through SEM-EDX surface analysis, electrochemical techniques and immersion testing. In this paper separation of the proteins of the mycelium produced by a non-corrosive strain and its culture along three generations was performed. cultures were prepared in batch in the presence and absence of pure Al and AA 2024, AA 7005 and AA 7075 alloys. The mycelia grown throughout the three generations increasingly recovered usual characteristics at the third replication, included their corrosiveness on Al and its alloys previously shown by all out strains. Among the bio-molecule fractions isolated and analysed during this preliminary study only the proteins revealed changes with the generation grown. When this fungal strain was cultured in the presence of alloy metal sheets electrophoresis of the protean fraction was correlative with the distinct mycelia behaviour observed, including corrosiveness on Al and its alloys. (Author) 30 refs

  19. Production of NbC reinforced aluminum matrix composites by mechanical alloying

    International Nuclear Information System (INIS)

    Silva, Marina Judice; Cardoso, Katia Regina; Travessa, Dilermando Nagle

    2014-01-01

    Aluminum and their alloys are key materials for the automotive and aerospace industries. The dispersion of hard ceramic particles in the Al soft matrix produces lightweight composites with interesting properties, as environmental resistance, high specific strength and stiffness, high thermal and electrical conductivity, and good wear resistance, encouraging their technological use. Powder metallurgy techniques like mechanical alloying (MA) are very attractive to design metal matrix composites, as they are able to achieve a homogeneous distribution of well dispersed particles inside the metal matrix. In this work, pure aluminum has been reinforced with particles of Niobium carbide (NbC), an extremely hard and stable refractory ceramic. NbC is frequently used as a grain growth inhibitor in micro-alloyed steel due to their low solubility in austenite. In the present work, NbC is expected to act as a reinforcing phase by its fine dispersion into the aluminum matrix, produced by MA. Composite powders produced after different milling times (up to 50h), with 10 and 20% (volume) of NbC were characterized by diffraction laser particle size analysis, scanning electron microscopy (SEM) and by X-ray diffraction (DRX), in order to establish a relationship between the milling time and the characteristics of the powder produced, as size and morphology, crystallite size and reinforcement distribution. This characterization is important in defining the MA process for production of composites for further consolidation by hot extrusion process. (author)

  20. Characterization of B4C-composite-reinforced aluminum alloy composites

    Science.gov (United States)

    Singh, Ram; Rai, R. N.

    2018-04-01

    Dry sliding wear tests conducted on Pin-on-disk wear test machine. The rotational speed of disc is ranging from (400-600rpm) and under loads ranging from (30-70 N) the contact time between the disc and pin is constant for each pin specimen of composites is 15 minute. In all manufacturing industries the uses of composite materials has been increasing globally, In the present study, an aluminum 5083 alloy is used as the matrix and 5% of weight percentage of Boron Carbide (B4C) as the reinforcing material. The composite is produced using stir casting technique. This is cost effective method. The aluminum 5083 matrix can be strengthened by reinforcing with hard ceramic particles like silicon carbide and boron carbide. In this experiment, aluminum 5083 alloy is selected as one of main material for making parts of the ship it has good mechanical properties, good corrosion resistance and it is can welded very easily and does have good strength. The samples are tested for hardness and tensile strength. The mechanical properties like Hardness can be increased by reinforcing aluminum 5083alloy 5% boron carbide (B4C) particles and tensile strength. Finally the Scanning Electron Microscope (SEM) analysis and EDS is done, which helps to study topography of composites and it produces images of a sample by scanning it with a focused beam of electrons and the presence of composition found in the matrix.