Showing papers on "Aluminium alloy published in 2012"
TL;DR: Laser shock peening (LSP) without ablative coating at various power densities was applied to AA6082 aluminium alloy to investigate corrosion behavior in a 0.6-M NaCl solution.
193 citations
TL;DR: In this article, the authors used nano-coated tungsten carbide drill heads to drill a composite plate made of carbon fiber reinforced plastic (CFRP) and aluminium alloy.
Abstract: Drilling and fastening of hybrid materials in one-shot operation reduces cycle time of assembly of aerospace structures. One of the most common problems encountered in automatic drilling and riveting of multimaterial is that the continuous chips curl up on the body of the tool. Drilling of carbon fiber reinforced plastic (CFRP) is manageable, but when the minute drill hits the aluminium (Al) or titanium (Ti), the hot and continuous chips produced during machining considerably damage the CFRP hole. This study aims to solve this problem by employing nano-coated drills on multimaterial made of CFRP and aluminium alloy. The influence of cutting parameters on the quality of the holes, chip formation and tool wear were also analyzed. Two types of tungsten carbide drills were used for the present study, one with nano-coating and the other, without nano coating. The experimental results indicated that the shape and the size of the chips are strongly influenced by feed rate. The thrust force generated during drilling of the composite plate with coated drills was 10–15% lesser when compared to that generated during drilling with uncoated drills; similarly, the thrust force in the aluminium alloy was 50% lesser with coated drills when compared to thrust force generated without coated drills. Thus, the use of nano-coated drills significantly reduced the surface roughness and thrust force when compared with uncoated tools.
172 citations
TL;DR: In this paper, high strength steel and aluminium alloy sheets were joined by mechanical clinching with dies for control of metal flow, and metal flow of the sheets was controlled by optimising a shape of the die.
172 citations
30 Oct 2012-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, two different grades of high strength steel (HSS), with different microstructures and strengths, were joined to AA6181-T4 Al alloy by FSW.
Abstract: The use of light-weight materials for industrial applications is a driving force for the development of joining techniques. Friction stir welding (FSW) inspired joints of dissimilar materials because it does not involve bulk melting of the basic components. Here, two different grades of high strength steel (HSS), with different microstructures and strengths, were joined to AA6181-T4 Al alloy by FSW. The purpose of this study is to clarify the influence of the distinct HSS base material on the joint efficiency. The joints were produced using the same welding parameter/setup and characterised regarding microstructure and mechanical properties. Both joints could be produced without any defects. Microstructure investigations reveal similar microstructure developments in both joints, although there are differences e.g. in the size and amount of detached steel particles in the aluminium alloy (heat and thermomechanical affected zone). The weld strengths are similar, showing that the joint efficiency depends foremost on the mechanical properties of the heat and the thermomechanical affected zone of the aluminium alloy.
160 citations
TL;DR: In this paper, the effect of deformation on ultrafine-grained microstructures produced by severe plastic deformation upon AA2024-T351 was investigated with respect to pitting and intergranular corrosion.
122 citations
TL;DR: SEM-based tomography of localized corrosion of AA2024-T351 aluminium alloy was achieved using selective detection of backscattered electrons as mentioned in this paper, which provided direct evidence that links the surface appearance of corroded alloy, the alloy microstructure and the corrosion propagation path.
106 citations
TL;DR: In this article, a homogeneous dispersion of the nanotubes at the micron scale is required in order to improve the mechanical properties of the metal matrix composite, which can be achieved using ball-milling through the mechanisms of plastic deformation and cold-welding.
103 citations
TL;DR: In this article, the corrosion protection of AA6063 aluminium alloy by cerium conversion, polyaniline conducting polymer and duplex coatings was investigated, and the electrochemical behavior was evaluated in aerated 3.5 ¼wt.% NaCl.
102 citations
TL;DR: In this article, a vast analysis of thermal fatigue cracks in aluminium alloy die casting is done using immersion test apparatus, which enables simulation of conditions during aluminium Alloy die casting and enables controlled thermal fatigue testing of materials.
99 citations
TL;DR: This work shows that the chemistry of the anion and cation are critical in achieving maximum wear protection for steel on aluminium system, and those ILs that exhibited low wear were shown to have formed protective tribofilms on the aluminium alloy surface.
Abstract: Ionic liquids have been shown to be highly effective lubricants for a steel on aluminium system. This work shows that the chemistry of the anion and cation are critical in achieving maximum wear protection. The performance of the ILs containing a diphenylphosphate (DPP) anion all showed low wear, as did some of the tris(pentafluoroethyl)trifluorophosphate (FAP) and bis(trifluoromethanesulfonyl)amide (NTf2) anion containing ILs. However, in the case of the FAP and NTf2 based systems, a cation dependence was observed, with relatively poor wear resistance obtained in the case of an imidazolium FAP and two pyrrolidinium NTf2 salts, probably due to tribocorrosion caused by the fluorine reaction with the aluminium substrate. The systems exhibiting poor performance generally had a lower viscosity, which also impacts on their tribological properties. Those ILs that exhibited low wear were shown to have formed protective tribofilms on the aluminium alloy surface.
94 citations
TL;DR: In this paper, a study of the effects of plasticity on the mechanism of intergranular cracking assisted by hydrogen induced embrittlement in an aluminium alloy was carried out using electron backscatter diffraction (EBSD) measurements of the associated crystal orientation evolution at the micron scale.
TL;DR: In this paper, a characterisation of oxides formed in pure Al and Al-Mg alloy melts was carried out and the potency of the oxide particles and the mechanism of inoculation by the oxides were discussed on the basis of the TEM results and theoretical analysis of the lattice misfits at the interfaces along specific orientation relationships.
Abstract: One of the main concerns in recycling aluminium alloy scrap is the removal of oxide inclusions. Understanding the nature and behaviour of oxide films in the alloy melts is an important step for developing efficient recycling technologies. In this work, characterisation of oxides formed in pure Al and Al–Mg alloy melts was carried out. In commercially pure Al melt, γ-Al2O3 platelets and α-Al2O3 particles were found to form at 750 and 920 °C, respectively. The oxides were in the form of liquid-like films consisting of numerous individual particles. The addition of 0.49 and 0.70 wt% Mg resulted in the formation of MgAl2O4, and the MgAl2O4 particles were {1 1 1} faceted and had a cube-on-cube orientation relationship with α-Al. The MgAl2O4 films were also liquid-like in which large numbers of the particles were held by the melt. Grain refinement was achieved by intensive shearing of the melts prior to solidification. It is believed that intensive melt shearing broke up the oxide films and dispersed the potent oxide particles which in turn enhanced the heterogeneous nucleation, resulting in grain refinement. The potency of the oxide particles and the mechanism of the inoculation by the oxides were discussed on the basis of the TEM results and theoretical analysis of the lattice misfits at the interfaces along specific orientation relationships.
TL;DR: In this article, the preliminary investigation of joining parameter at various levels as well as the mechanical properties of friction spot joining of aluminium alloy (A5052) to polyethylene terephthalate (PET) was conducted.
Abstract: The weld strength of thermoplastics with aluminium alloy, such as high density polyethylene and polypropylene sheets, is influenced by friction stir welding parameters. This paper focuses on the preliminary investigation of joining parameter at various levels as well as the mechanical properties of friction spot joining (FSJ) of aluminium alloy (A5052) to polyethylene terephthalate (PET). A number of FSJ experiments were carried out to obtain optimum mechanical properties by adjusting the plunge speed and plunge depth in the ranges of 5–40 mm min−1 and 0·4–0·7 mm respectively, while spindle speed remains constant at 3000 rev min−1. The results indicated that A5052 and PET successfully joined with the aid of frictional heat energy originated from the friction spot welding process. The effect of plunge speed on the joined area and the effect of formation of bubbles at the interface of joints on the shear strength of joint are discussed.
TL;DR: In this paper, a tin interlayer was inserted in between the faying surfaces during ultrasonic spot welding to improve the strength of dissimilar joints of AZ31B-H24 magnesium alloy to 5754-O aluminium alloy.
Abstract: Welding of magnesium to aluminium alloys is enormously challenging due to the formation of brittle Al12Mg17 intermetallic compounds (IMCs). This study was aimed at improving the strength of dissimilar joints of AZ31B-H24 magnesium alloy to 5754-O aluminium alloy by using a tin interlayer inserted in between the faying surfaces during ultrasonic spot welding. The addition of tin interlayer was observed to successfully eliminate the brittle Al12Mg17 IMCs, which were replaced by a layer of composite-like tin and Mg2Sn structure. Failure during the tensile lap shear tests occurred through the interior of the blended interlayer as revealed by X-ray diffraction and SEM observations. As a result, the addition of a tin interlayer resulted in a significant improvement in both joint strength and failure energy of magnesium to aluminium dissimilar joints and also led to an energy saving because the optimal welding energy required to achieve the highest strength decreased from ∼1250 to ∼1000 J.
TL;DR: In this article, the effects of volume fraction and particle size of boron carbide on the abrasive wear properties of B4C particle reinforced aluminium alloy composites have been studied.
Abstract: In this study, the effects of volume fraction and particle size of boron carbide on the abrasive wear properties of B4C particle reinforced aluminium alloy composites have been studied. For this purpose, a block-on-disc abrasion test apparatus was utilized where the samples slid against the abrasive suspension mixture at room conditions. The volume loss, specific wear rate and roughness of the samples have been evaluated. The effects of sliding time, particle content and particle size of B4C particles on the abrasive wear properties of the composites have been investigated. The dominant wear mechanisms were identified using scanning electron microscopy. The results showed that the specific wear rate of composites decreased with increasing particle volume fraction. Furthermore, the specific wear rate decreased with increasing the size of particle for the composites containing the same amount of B4C. Hence, it is deduced that aluminium alloy composites reinforced with larger B4C particles are more effective against the abrasive suspension mixture than those reinforced with smaller B4C particles.
TL;DR: In this paper, the pitting corrosion susceptibility and its role on the hydrogen embrittlement behavior of AZ80 magnesium alloy were studied using slow strain rate testing (SSRT), electrochemical technique and immersion test method.
TL;DR: In this article, 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.
Abstract: 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
TL;DR: In this article, the effect of B 4 C volume fraction, sliding velocity, applied load and sliding distance on reciprocal dry wear behavior of composites was studied using general full factorial experimental design.
TL;DR: In this paper, an atmospheric corrosion of aluminium alloy 2024-T3 exposed to salt lakes environment for 6 years was investigated by weight loss, analysis of morphology and corrosion products, which showed an increase in the mass loss with a high rate in the first 2 years, and tended to stabilise over time.
TL;DR: In this article, the electromagnetic expanding ring experiment was used as the primary tool for examining the ductility behavior of metals, and the experimental observations on cold-rolled copper Cu-ETP, aluminium alloy Al 7075, barrel steel and tungsten heavy alloy are reported.
TL;DR: In this paper, a heat treated aluminium alloy EN-AW 1050A H24 is proposed as base material for the manufacturing of innovative passive energy dissipation devices for seismic protection of framed buildings.
TL;DR: In this article, the corrosion protection ability of hybrid oxy silane nano-composite coatings deposited on AA2024 by sol-gel technique was studied, where a cerium salt, Ce2(SO4)3, was used as inhibitor of the corrosion process.
TL;DR: In this paper, a model was developed and applied to the case of dissimilar joining of aluminium and magnesium alloys using ultrasonic welding, and the model accounts for microbond formation during welding, diffusion across the joint line, as well as nucleation, spreading and thickening of the first IMC layer (Mg17Al12 phase) and the formation and simultaneous thickness of the second (Al3Mg2) layer.
Abstract: Intermetallic compound (IMC) formation at the joint line usually has strongly detrimental effect on the performance of dissimilar metal welds. To understand the formation of IMC interlayers, and explore strategies to control their growth, a model has been developed and applied to the case of dissimilar joining of aluminium and magnesium alloys using ultrasonic welding. The model accounts for microbond formation during welding, diffusion across the joint line, as well as nucleation, spreading and thickening of the first IMC layer (Mg17Al12 phase) and the formation and simultaneous thickening of the second (Al3Mg2) layer. The model predictions match measurements reasonably well and the model has been used to predict the sensitivity of IMC layer thickness to weld temperature and time.
TL;DR: In this article, the microstructures and properties of Al-Si-Fe alloy matrix composites reinforced with different weight fractions of breadfruit seed hull (husk) ash particles of size 500nm were investigated.
Abstract: The microstructures and properties of Al–Si–Fe alloy matrix composites reinforced with different weight fractions of breadfruit seed hull (husk) ash particles of size 500 nm were investigated. Six (6) different weight fractions of breadfruit seed hull ash particles were added to aluminium alloy matrix using a double stir-casting method. Microstructural analysis shows that with the increase of the reinforcement weight fraction, the matrix grain size decreases. The mechanical properties of the composites are improved over the matrix materials, except for the slightly decrease of the impact energy. Fracture surface examination indicates that there is a good interfacial bonding between the aluminium alloy matrix and the breadfruit seed hull ash particles and that fracture initiation does not occur at the particle-matrix interface. Hence, incorporation of breadfruit seed hull ash particles in aluminium matrix can lead to the production of low cost aluminium composites with improved hardness and strength. These composites can find applications in automotive components where light weight materials are required with good stiffness and strength.
TL;DR: In this paper, the effects of particle size distribution, component ratio, particle packing arrangement, and chemical constitution on the laser sintering behavior of blended hypoeutectic Al-Si powders were studied.
Abstract: Purpose – The purpose of this paper is to study the effects of particle size distribution, component ratio, particle packing arrangement, and chemical constitution on the laser sintering behaviour of blended hypoeutectic Al‐Si powders.Design/methodology/approach – A range of bimodal and trimodal powder blends were created through mixing Al‐12Si and pure aluminium powder. The powder blends were then processed using selective laser sintering to investigate the effect of alloy composition, powder particle size and bed density on densification and microstructural evolution.Findings – For all of the powder blends the sintered density increases with the specific laser energy input until a saturation level is reached. Beyond this saturation level no further increase in sintered density is obtained for an increase in specific laser energy input. However, the peak density achieved for a given blend varied significantly with the chemical constitution of the alloy, peaking at approximately 9 wt% Si. The tap density ...
TL;DR: In this paper, the corrosion behaviour of a magnetron sputtered Al-Cu/Al-Cu-Mg model alloy couple in sulphate solutions has been investigated to gain insight into the galvanic coupling between the matrix and S-Al 2 CuMg particles in the 2024 aluminium alloy (AA2024).
TL;DR: In this paper, the authors investigated the wear behavior of Al-SiCp metal matrix composite for varying reinforcement content, applied load, sliding speed and time, and obtained the optimal combination of the four controlling parameters for minimum wear.
Abstract: Aluminium metal matrix composite is a relatively new material that has proved its position in automobile, aerospace and other engineering design applications due to its wear resistance and substantial hardness. Need for improved tribological performance has led to the design and selection of newer variants of the composite. The present investigation deals with the study of wear behaviour of Al-SiCp metal matrix composite for varying reinforcement content, applied load, sliding speed and time. Aluminium metal matrix composites reinforced with SiC particles are prepared by liquid metallurgy route using LM6 aluminium alloy and silicon carbide particles (size ~ 37 μm) by varying the weight fraction of SiC in the range of 5% - 10%. The material is synthesized by stir casting process in an electric melting furnace. The materials are then subjected to wear testing in a multitribotester using block on roller configuration. A plan of experiments based on L27 Taguchi orthogonal array is used to acquire the wear data in a controlled way. An analysis of variance is employed to investigate the influence of four controlling parameters, viz., SiC content, normal load, sliding speed and sliding time on dry sliding wear of the composites. It is observed that SiC content, sliding speed and normal load significantly affect the dry sliding wear. The optimal combination of the four controlling parameters is also obtained for minimum wear. The microstructure study of worn surfaces indicates nature of wear to be mostly abrasive.
TL;DR: In this article, the effect of corrosion exposure on ultra thin (t < 0.4mm) 2024-T3 aluminium sheet thickness is investigated; the results were correlated to observed corrosion degradation mechanisms.
TL;DR: In this paper, AA2024 clad with AA1050 was immersed in CeCl3 solutions under aerated and O2 saturated conditions to promote the deposition of cerium species.
TL;DR: In this paper, a pressureless infiltration technique was used to produce IPCs by infiltrating molten aluminium alloys into a range of gel-cast ceramic foams produced from alumina, mullite, and spinel.