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Several studies using Friction Stir Welding (FSW) on dissimilar Aluminium and Copper weld configurations and the mechanical and microstructure characteristics, as well as the identification of intermetallic phases that appear in the weld region, have been conducted. Indeed, earlier several studies had been conducted in both lap and butt FSW joint designs. Even so, Al–Cu lap welding has received further attention than butt–welding, which has attracted only a few studies thus far. The studies ended with varying findings and were unable to reach high strengths despite the fact that very few studies addressed tool placement factors. The present investigation starts with butt–welding of AA1050 and pure Cu sheet by employing the FSW procedure. Experimental trails were designed using the L16 array (Taguchi’s technique) with distinct combinations of tool spinning speed, tool offset, welding speed, and plunge depth. Weld parameters such as compressive strength (CS), ultimate tensile strength (UTS), and average hardness at nugget zone (AHNZ) were evaluated using three different optimization methodologies, i.e. the WASPAS method, Alibaba and the Forty Thieves algorithm, and the Taguchi–WASPAS method, to find out the best weld constraint arrangement for maximizing the welded joint mechanical characteristics. ANOVA test was also conducted, which revealed that welding speed is the most significant and influential FSW factor for Al–Cu butt–welding using FSW. Finally, confirmatory tests were piloted to check the consistency of the predicted FSW parameters. [ABSTRACT FROM AUTHOR]

A Novel Technique is proposed in this investigation called Double Stage Friction Stir Spot Extrusion Welding (DSFSSEW). It is carried out in two stages by using a pin-shoulder tool in step 1 and a pin-less tool in step 2 to investigate the joint strength of the AA1050 sheet. The advantage of this new double-stage FSSEW technique compared to the classical FSSW led to the elimination of the keyhole, which is an intrinsic flaw of the Friction Stir Spot Welding (FSSW) process resulting in higher mechanical joint properties. The impact of the plunge depth and tool revolving speed on the characteristics of the bond was investigated. The height of the extruded aluminium was increased by increasing the tool rotation speed and the plunging depth which was the effective variable. The joint strength was increased in step 2. The two sheets are bonding together at a line of the interface by a mechanical interlock formed by a continuous metal flow of aluminium extrusion that is free of flaws. There were two mechanisms of failure in the studied samples: cleavage of the aluminium metal at the tool trace and shearing of the extruded aluminium, respectively. The suggested method is novel and has a great potential for future investigation, this work might pave the way for studies of welding with additional alloys, both similar and dissimilar to those already studied. [ABSTRACT FROM AUTHOR]

The friction spot welding process is used to join the hybrid joint of aluminium to polymer. AA 1050 Aluminum alloy and polyethylene polymer (type of plastic) were used for joining. Aluminium surface treatment was done to increase the wettability of it. The surface treatment was done by electrochemical treatment. Two parameters of the joining process were used: (1, 1.5 and 2) min. (920, 1340 and 1500) rpm for time and rotational speed, respectively. Many tests for the joint are done: shear test and Scanning electron microscopy (SEM). Using the Minitab program, the effect of the parameters on the joint was analysed. The maximum value of the shear force was (1587 N) at 1.5 min. time and 1340 rpm rotational speed. The minimum shear force was (589 N) at 1 min. time and 920 rpm rotational speed. The joints which were tested failed by an interfacial shear with a ductile fracture of the polymer side. The process of joining mechanism occurred through a mechanical interlocking between the molten polymer and the surface of the AA 1050 aluminium specimen, cohesive and adhesive. The average thickness for the joint of the tested specimens was 4μm. [ABSTRACT FROM AUTHOR]

Friction stir processing (FSP) offers a unique opportunity to tailor the microstructure and improve the mechanical properties due to the combination of extensive strains, high temperatures, and high-strain rates inherent to the process. Reactive friction stir processing was carried out in order to produce in situ Al/(Al13Fe4 + Al2O3) hybrid nanocomposites on wrought/as-annealed (673 K) AA1050 substrate. The active mixture of pre-ball milled Fe2O3 + Al powder was introduced into the stir zone by pre-placing it on the substrate. Microstructural characterisation showed that the Al13Fe4 and Al2O3 formed as the reaction products in a matrix of the dynamically restored aluminium matrix. The aluminium matrix means grain size was found to decrease markedly to 3.4 and 2 μm from ~55 μm and 40–50 μm after FSP using wrought and as-annealed substrates employing electron backscattered diffraction detectors, respectively. In addition, tensile testing results were indicative that the fabricated surface nanocomposite on the as-annealed substrate offered a greater ultimate tensile strength (~160 MPa) and hardness (73 HV) than those (146 MPa, and 60 HV) of the nanocomposite formed on the wrought substrate. [ABSTRACT FROM AUTHOR]

In this study, hybrid AA1050/Al2O3/TiO2 composites have been produced via combined liquid casting and powder metallurgy techniques. Degassing was utilized to improve the wettability of molten aluminum alloys, and then successful bonding was generated between aluminum matrix and reinforcement particles during the powder metallurgy technique. As the base matrix and reinforcements, AA1050 alloy, Al2O3 and TiO2 particles were taken, respectively. Then, content values of 5Wt.% of Al2O3 in the mesh size of 20 μm and 2.5 and 5 wt. % of TiO2 particles with mesh size of 5μm were added to the AA1050 matrix. For each composite sample, ceramic particles were warmed to 600°C in order to improve wettability and distribution. An identical scattering of subdivisions was observed through aluminum (as matrix) in the microstructural study. To measure the wear resistance, the mechanism of rotary wear test was used. The achieved results illustrated that the fabrication of hybrid composites is an ideal approach to improve the wear resistance of Al-based composites. By increasing of TiO2 Wt.% up to 5% for all composite samples, the wear rate improved to less than half of the monolithic Al alloy value for each composite sample. [ABSTRACT FROM AUTHOR]

Tribological behaviors of the plasma electrolytic oxidation (PEO)-treated Al1050 alloy surface without and with Ni-P deposits was examined by analyzing of the width of abrasion groove, weight loss, friction coefficient and composition at the wear track after a 100 m ball-on-disc test. The surface color, surface and cross-sectional morphologies and surface roughness (Ra) were also investigated to explain different wear behaviors of PEO films without and with Ni-P deposit. After the 100 m ball-on-disc test, a circular abrasion groove with relatively large width and shallow depth was formed when Ni-P particles cover the top surface of PEO films, but a relatively narrow and deep circular abrasion groove was formed on the Ni-P layer-covered PEO film surface. Iron was only detected at the wear track of 5 and 10 μm PEO films without Ni-P deposit, suggesting that the steel ball is worn out by the PEO films but not by the Ni-P deposit. An extremely large amount of weight loss was obtained from the Ni-P layer-covered PEO film surface, which could be related to the high density and low hardness of the Ni-P layer. [ABSTRACT FROM AUTHOR]

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The current research designed a statistical model for the bobbin tool friction stir processing (BT-FSP) of AA1050 aluminum alloy using the Response Surface Method (RSM). The analysis studied the influence of tool travel speeds of 100, 200, and 300 mm/min and different pin geometries (triangle, square, and cylindrical) at a constant tool rotation speed (RS) of 600 rpm on processing 8 mm thickness AA1050. The developed mathematical model optimizes the effect of the applied BT-FSP parameters on machine torque, processing zone (PZ) temperature, surface roughness, hardness values, and ultimate tensile strength (UTS). The experimental design is based on the Face Central Composite Design (FCCD), using linear and quadratic polynomial equations to develop the mathematical models. The results show that the proposed model adequately predicts the responses within the processing parameters, and the pin geometry is the most influential parameter during the BT-FSP of AA1050. The analysis of variance exhibit that the developed mathematical models can effectively predict the values of the machine torque, PZ temperature, surface roughness, hardness, and UTS with a confidence level of over 95% for the AA1050 BT-FSP. The optimization process shows that the optimum parameters to attain the highest mechanical properties in terms of hardness and tensile strength at the lowest surface roughness and machine torque are travel speed (TS) of 200 mm/min using cylindrical (Cy) pin geometry at the constant RS of 600 rpm. The PZ temperature of the processed specimens decreased with increasing TS at different pin geometries. Meanwhile, the surface roughness of the processed passes and machine torque increased with increasing the TS at different pin geometries. Increasing TS from 100 to 300 mm/min increases the hardness values of the processed materials using different pin geometries. The highest UTS of 79 MPa for the processed specimens was attained at the TS of 200 mm/min and RS of 600 rpm using the Cy pin geometry. [ABSTRACT FROM AUTHOR]

In the present study, bobbin tool friction stir processing (BT-FSP) with a cylindrical pin was utilized to produce bulk processed AA1050 and AA1050/6.5 vol% silica fume (SF) composite at a rotation speed of 600 rpm using two travel speeds of 100 and 200 mm/min. The BT-FSP temperature was measured for both processed materials. Phase composition, relative density, macrostructure, hardness, ultimate tensile strength, and compressive strength were examined for the AA1050 base material, processed AA1050 and AA1050/SF composite. The results showed that the temperature of BT-FSP was increased with SF addition. The addition of fine SF resulted in a small crystallite size compared to the AA1050 BM and the processed AA1050. Moreover, the SF addition to the AA1050 matrix improved mechanical properties in terms of hardness, ultimate tensile strength, and compressive strength compared to AA1050 BM and processed AA1050. The bulk AA1050/6.5 vol% nano SF composite produced at 600 rpm and 200 mm/min showed remarkable enhancements in properties compared to AA1050 parent material; i.e. 50% in hardness, 11% in compressive strength, and 40% in ultimate tensile strength. [ABSTRACT FROM AUTHOR]

AA1050 plates of 8 mm thickness were processed via bobbin-tool friction stir processing technique at a constant rotation speed of 600 rpm and different travel speeds ranging from 50 to 300 mm/min using three-pin geometries of triangle, square, and cylindrical. The temperatures of the processed zone, the advancing side, and the retreating side were measured; the machine torque during processing was also recorded. The processed materials were evaluated in terms of surface roughness, macrostructure, tensile properties, and hardness measurements. The fracture surfaces of the tensile fractured specimens were investigated using SEM. The results indicated that the pin geometry and processing speed significantly affect the generated heat input and the morphology of the processed zone. The peak temperature in the center of the processed zone decreases with increasing the travel speed from 50 to 300 mm/min at all applied pin geometries. The maximum temperature of ~400 °C was reached using the cylindrical pin geometry. The machine torque increases with increasing the travel speed at all applied pin geometries, and the highest torque value of 73 N.m is recorded using the square pin geometry at 300 mm/min travel speed. The top surface roughness of the processed area using the cylindrical pin is lower than that given by the other pin geometries. Under all applied conditions, the hardness of the processed area increases with increasing travel speed, and the cylindrical pin shows a higher hardness than the other pin geometries with 19% enhancement over the BM. The AA1050 processed using a cylindrical pin at 200 mm/min travel speed and a rotation speed of 600 rpm produces a sound processing zone with the highest ultimate tensile strength of 79 MPa. [ABSTRACT FROM AUTHOR]

This paper aims at studying the impact of focal position offset on joint integrity of AA1050 battery busbar during remote laser welding. Welding experiments were conducted at different focal position offsets in the AA1050 L-joint with the integration of laser beam oscillation. The impact of focal position offset was evaluated by multiple joint indicators including weld geometry, thermal profile, weld porosity and mechanical strength. Results showed that defocusing of the laser beam tends to be favourable for the reduction of peak temperatures and weld porosity. However, a defocusing more than 3 mm can lead to 60% drop in bonding integrity and 40% loss of joint strength. A tolerance window of [-2 1] mm was determined for the focal position offset, corresponding to 70% and 30% of the Rayleigh length. This result is a useful reference to inform precise focal position control with respect to the accumulated variations of part tolerance, part-to-part gap and part positioning errors. This study also indicated that the thermal measurement can be a potential approach for in-process monitoring of joint integrity. Indeed, the peak temperature near the weld zone showed good linear correlation with off-line detectable joint indicators including weld depth, weld width at interface, weld tensile strength and weld porosity.

Friction stir processing (FSP) offers a unique opportunity to tailor the microstructure and improve the mechanical properties due to the combination of extensive strains, high temperatures, and high-strain rates inherent to the process. Reactive friction stir processing was carried out in order to produce in situ Al/(Al13Fe4 + Al2O3) hybrid nanocomposites on wrought/as-annealed (673 K) AA1050 substrate. The active mixture of pre-ball milled Fe2O3 + Al powder was introduced into the stir zone by pre-placing it on the substrate. Microstructural characterisation showed that the Al13Fe4 and Al2O3 formed as the reaction products in a matrix of the dynamically restored aluminium matrix. The aluminium matrix means grain size was found to decrease markedly to 3.4 and 2 μm from ~55 μm and 40–50 μm after FSP using wrought and as-annealed substrates employing electron backscattered diffraction detectors, respectively. In addition, tensile testing results were indicative that the fabricated surface nanocomposite on the as-annealed substrate offered a greater ultimate tensile strength (~160 MPa) and hardness (73 HV) than those (146 MPa, and 60 HV) of the nanocomposite formed on the wrought substrate.

This work aims to optimize the performance evaluation characteristics such as the temperature at the weld center of the lap joint (Tw), the tensile shear load (TSL), and the hardness using an experimental design experiment for bobbin tool friction stir welding (BT-FSW) of AA1050 lap joints. BT-FSW is characterized by a fully penetrated pin and double-sided shoulder that promote symmetrical solid-state welds. This study contributes to improving the quality of 10 mm thick lap joints and addressing challenges to obtaining a sound weld deprived of any defects. Taguchi L9 orthogonal array (OA) experimental design was performed. Three different pin shapes (cylindrical, triangular, and square) and three levels of welding travel speeds of 200, 400, and 600 mm/min were selected as input controllable process parameters at a constant tool rotation speed of 600 rpm. A travel speed of 200 mm/min with square pin geometry significantly improves the TSL of the joint up to 6491 N. However, the hardness characteristic is optimized by using 600 mm/min travel speed and a cylindrical tool pin. The minimum temperature in the weld joint can be obtained using 600 mm/min or more with triangular pin geometry. From ANOVA results, it was seen that the BT-FSW of AA 1050 thick lap joints performance in terms of TLS and Tw were greatly influenced by travel speed; however, the tool shape influences the hardness more. For the validation of the models, BT-FSW experiments have been carried out for AA1050 using the applied processing parameters. Furthermore, regression models were developed to predict the Tw, TSL, and hardness. The calculated performance properties from the mathematical models were in an acceptable range compared to the measured experimental values. [ABSTRACT FROM AUTHOR]

Several studies had been performed on accumulative roll bonding (ARB) for AA1050; however, most of them were conducted at room temperature. Here, the ARB process was performed on AA1050 plates through nine cycles at elevated temperature. An innovation introduced a new parameter ( U T S × E l. ε ) to compare the strength-elongation balance between the present study and previous works. Also, as another parameter, the toughness was compared. Comparing these parameters with previous works showed that the considered samples in the present study performed 14 to 63% better than the other samples, so they were more industrially favorable in terms of mechanical behavior and performance. ARB process at elevated temperature may slightly lead to grain growth compared to room/cryogenic temperature, but creates a better elongation, which ultimately leads to a better balance of the strength-elongation parameter. The results showed that the effect of inter-cycle heating was found significant on microstructural evolution and mechanical behavior. Upon five cycles of the process, the grain size was decreased from 35 to 1.8 μm. The yield strength and ultimate strength increased up to 305% and 94%, respectively. Microhardness test showed that warm ARB reduces inhomogeneity factor in the thickness after 3 cycles. Fractography by SEM showed that the sample failed through shear ductile rupture and that the dimples became smaller, more elongated, and shallower onto the failure surface as the number of ARB cycles increased. In short, the warm process is preferred to the cold process to achieve better mechanical performance and toughness. [ABSTRACT FROM AUTHOR]

The pitting corrosion of an aluminum alloy AA1050 after being processed by continuous closed die forging (CCDF) was evaluated by cyclic potentiodynamic polarization (CPP). Microstructure evolution, mechanical and corrosion behaviors were studied as a function of the total strain imposed. The CCDF process was carried out at 0, 16 and 24 passes with loading times of 10 and 15 s. The electron backscatter diffraction (EBSD) analysis revealed a grain refinement of 0.78 µm after 24 passes, which promoted an increment in the yield strength (YS), ultimate tensile strength (UTS) and vickers hardness (HV) by a factor of 9, 3 and 2 respectively; but the uniform strain and strain to rupture decreased by 93% and 72% respectively. Resistance to corrosion after 16 and 24 passes was compared with the reference material (0 passes), using CPP in a Na2S04 0.1 mol/l +100 mg/l of NaCl electrolyte. Results showed that the specimens with 24 passes decreased its corrosion rate one order of magnitude. In addition, specimens with very fine grain sizes have shown nobler pitting potential and lower pitting volume fraction than coarse grain specimens.

In this study, hybrid AA1050/Al2O3/TiO2 composites have been produced via combined liquid casting and powder metallurgy techniques. Degassing was utilized to improve the wettability of molten aluminum alloys, and then successful bonding was generated between aluminum matrix and reinforcement particles during the powder metallurgy technique. As the base matrix and reinforcements, AA1050 alloy, Al2O3 and TiO2 particles were taken, respectively. Then, content values of 5Wt.% of Al2O3 in the mesh size of 20 μm and 2.5 and 5 wt. % of TiO2 particles with mesh size of 5μm were added to the AA1050 matrix. For each composite sample, ceramic particles were warmed to 600°C in order to improve wettability and distribution. An identical scattering of subdivisions was observed through aluminum (as matrix) in the microstructural study. To measure the wear resistance, the mechanism of rotary wear test was used. The achieved results illustrated that the fabrication of hybrid composites is an ideal approach to improve the wear resistance of Al-based composites. By increasing of TiO2 Wt.% up to 5% for all composite samples, the wear rate improved to less than half of the monolithic Al alloy value for each composite sample.

In this study, the fracture toughness of the multi-layered commercial pure aluminum samples (AA1050) prepared by warm accumulative roll bonding (WARB) was investigated for the first time. Based on the ASTM E561 standard, the R-curve method was utilized to measure the plane stress fracture toughness. Compact tension (CT) samples were prepared from the sheets that were processed by different ARB cycles. Mechanical properties, microstructure, and fracture surfaces of the CT samples were studied by uniaxial tensile test, electron backscatter diffraction (EBSD), and scanning electron microscopy (SEM), respectively. By increasing the number of WARB cycles, fracture toughness increased; after five cycles, 78% enhancement was observed compared to the pre-processed state. A correlation was seen between the fracture toughness variations and ultimate tensile strength (UTS). WARB enhanced UTS up to 95%, while the grain size showed a reduction from 35 to 1.8 μm. Measured fracture toughness values were compared with the room temperature ARB outcomes, and the effective parameters were analyzed. Fractography results indicated that the presence of tiny cliffs and furrows and hollow under fatigue loading zones and shear ductile rupture in the Quasi-static tensile loading zone. [ABSTRACT FROM AUTHOR]

In this study, the formation of porous Al2O3 on commercial 1050 aluminium alloy (AA1050) in 2 M sulfuric acid (H2SO4) electrolyte was investigated. Anodization was performed at 12 V and 15 V specimens for a charge density of 757 mC/cm2 and 3231 mC/cm2. The resulting oxides were analyzed using scanning electron microscopy (SEM). According to analysis, a hexagonal oxide formation containing more than one nano pore was observed on the surface of the specimen. The structural properties of the porous oxide film were analyzed with electrochemical impedance spectroscopy (EIS) analysis and film-related features such as thickness of the porous and the barrier layer were obtained. [ABSTRACT FROM AUTHOR]

A high-entropy alloy (HEA) is a multi-component solid solution alloy stabilized by high entropy of mixing. These alloys are demanded in combustion engines, gas turbine components and medical implants. Lack of fusion and presence of pores are the main problems in processing of HEA using laser surface alloying process. This paper investigates the laser surface alloying process performance for alloying HEA (AlCu0.5FeNiTi) over AA1050 Al alloy. The effect of processing parameters on dilution percent, aspect ratio and clad angle have been studied, comprehensively. Empirical models for the above responses have been developed from experimental data. The optimization of these models result in 46.490%, 5.700% and 4.019% improvements in dilution percent, aspect ratio and clad angle, respectively. Lack of fusion, number of pores and their sizes were reduced under optimal parameters. [ABSTRACT FROM AUTHOR]

Polyorganosilazane (PSZ) has been used for many years as a ceramic precursor for the preparation of silicon carbonitrides. Recently, polymethyl (hydro)/polydimethylsilazane-derived coatings that can be cured with atmospheric moisture at low temperatures have attracted interest due to their hydrophobic nature and electrochemical properties. In this work, polymethyl (hydro)/polydimethylsilazane-derived coatings have been deposited on aluminum alloy AA1050. The effect of the PSZ precursor concentration (5–40 v/v%) on the final properties of the coatings has been investigated. Butyl acetate has been employed as solvent. The layers were applied on the substrate by dipping. The experimental results showed that the concentration of the PSZ in the solvent strongly affects the dry thickness of the hybrid layer. The electrochemical impedance spectroscopy measurements revealed that the coatings derived from PSZ precursor concentration higher than 20 v/v% are protective and homogenous. Contact angle measurements evidenced that the presence of the coatings increased the hydrophobicity of the substrate as well as the oleophobicity regardless of the dilution in the organic solvent. The graffiti resistance of the coatings has been demonstrated to be acceptable regardless of the dilution of the PSZ precursor, in the investigated range. [ABSTRACT FROM AUTHOR]

In this work, three mathematical models for the heat generation during bobbin tool friction stir welding (BT-FSW) of aluminum using three tool pin geometries have been proposed. The models have utilized and updated the available models for the heat generation during the conventional tool friction stir welding (CT-FSW). For the validation of the models, BT-FSW experiments have been carried out for aluminum alloy AA1050 using three different pin geometries (cylindrical, square, and triangular), at different welding speeds of 200, 400, 600, 800, and 1000 mm/min and a constant tool rotation speed of 600 rpm. The welding temperatures during BT-FSW have been measured to be compared with that calculated from the models at the same parameters. It has been found that the calculated welding temperatures from the models and that measured during BT-FSW are in good agreement at all the investigated welding speeds especially in case of the square and cylindrical pins, proving the validity of the developed models for the predication of the heat generation as well as the welding temperatures. This will allow proper designing of the BT-FSW parameters and avoiding the conditions that can deteriorate the joint quality and properties.

Friction Stir Welding (FSW) is a solid state welding process used for welding similar and dissimilar materials. This welding technique allows welding of Aluminum alloys which present difficulties in fusion joining and allows different material couples to be welded continuously. In this study, 1050 aluminum alloy and commercially pure copper to increase heat input were produced at high rotation rate (2440 rev/min) with four different pin position (0-1-1.5-2 mm) and three different weld speeds (20-30-50 mm/min) by friction stir welding. The influence of welding parameters on microstructure and mechanical properties of the joints was investigated. Tensile and bending tests and microhardness measurements were used to determine of mechanical properties. Nugget zone microstructures were investigated by optical microscope and scanning electron microscope (SEM) and were analyzed in energy-dispersive X-ray spectroscopy (EDX). Depending on the XRD analysis results intermetallic phase was observed to form in the interfacial region. In the tensile test results, 83.55% weld performance was obtained in the friction stir welding merge of Al-Cu.

Sürtünme karıştırma kaynağı (SKK) aynı veya farklı cins malzemelerin birleştirilmesinde kullanılan katı hal birleştirme yöntemidir. Bu yöntem, ilk olarak ergitme kaynak teknikleri ile birleştirilmesinde zorluklarla karşılaşılan alüminyum alaşımlarının birleştirilmesinde kullanılmış olmakla beraber günümüzde farklı malzeme çiftlerinin başarılı bir şekilde birleştirilmesine de olanak vermektedir. Bu çalışmada, alüminyum (AA1050) ve bakır levhalar, ısı girdisini arttırmak amacı ile yüksek takım dönme hızında (2440 dev/dk.), üç farklı kaynak hızlarında (20, 30, 50 mm/dk.) ve dört farklı takım konumlandırmasında (0-1-1.5-2 mm) SKK ile birleştirilmiştir. Kaynak parametrelerinin mekanik ve mikroyapı özeliklerine etkisi incelenmiştir. Mekanik özelliklerinin tespiti amacıyla çekme ve eğme testleri ile mikrosertlik ölçümleri yapılmıştır. Kaynak bölgesi mikroyapıları, optik mikroskop ve taramalı elektron mikroskobu (SEM) ile incelenmiş ve EDX analizleri yapılmıştır. Kaynak bölgesinde meydana gelen fazları incelemek için yapılan XRD analiz sonuçlarında intermetalik fazlar tespit edilmiştir. Sürtünme karıştırma kaynağı yapılmış Al-Cu parçaların çekme testi sonuçlarında %83.55 kaynak performansı elde edilmiştir.

Incremental sheet forming (ISF) is an economical process for batch production. This paper investigates post-forming mechanical properties with an emphasis on the relationship between residual stresses, strengths, micro-hardness and the strain-hardening exponent. Moreover, the influence of important process parameters on the post-forming tensile properties and hardness is analyzed. A Taguchi statistical analysis method is applied to study the effect of forming parameters and identify the best combinations to enhance the mechanical properties of the commercial aluminum. The results reveal that direct relationships exist for the plots of: (i) the strain-hardening exponent vs. the post-necking strain and (ii) difference of post-forming strengths vs. the strain-hardening exponent. Furthermore, the post-forming yield strength can be enhanced by 66.9% through the Single Point Incremental Forming (SPIF). Similarly, the ductility can be doubled by conducting the SPIF after performing the annealing of the as-received rolled sheet. In the present study, parts formed at a wall angle (θ) of 40° with a tool diameter (d) of 6 mm exhibit the highest strength. Moreover, most ductile parts will be obtained at ω = 1500 rpm, d = 22 mm and θ = 20°. It has also been shown that the compressive residual stresses are favorable for higher yield strength and improve hardness of the formed parts.

High-cycle fatigue (HCF) and low-cycle fatigue (LCF) fatigue lives of rolled AA1100 and AA1050 aluminum sheets along different directions were evaluated at room temperature. Four types of samples denoted as longitudinal (L) and transverse (T) to the rolling direction were compared because the samples along the two typical directions show an obvious anisotropy. A cantilever plane-bending and multi-type fatigue testing machine was specially designed for this purpose. Deflection-controlled fatigue tests were conducted under fully reversed loading. The longest fatigue lives in the LCF region were obtained for AA1050 (L) while AA1100 (L) samples had the longest fatigue lives in the HCF region. [ABSTRACT FROM AUTHOR]

In this work, organosilane-derived sol-gel films containing different amounts of cerium ions applied on AA 1050 were investigated. The sol-gel coatings were prepared from 3-glycidoxypropyltrimethoxysilane (GPTMS) and methyltriethoxysilane (MTES) mixtures with the addition of cerium nitrate in order to achieve different concentrations of Ce ions (from 10 −5 M to 10 −2 M). The effect of the cerium load on the structure of the cured sol-gel films was investigated by means of solid state NMR and FT-IR spectroscopy. The corrosion protection properties of the different sol-gel layers were investigated mainly by means potentiodynamic curves and electrochemical impedance spectroscopy (EIS). FT-IR and solid state NMR suggested a significant influence of the Ce cations on the network structure: not only the degree of condensation decreases with Ce addition but also the structural modification of the silsesquioxane network is observed with preferential formation of ladder-like species for low Ce 3+ content and cages predominance for Ce/Si molar ratio greater than 0.039, i.e. [Ce 3+ ] = 1·10 −4 M. Electrochemical tests revealed that the effect of Ce ions on the structure of the coatings does not lead to remarkable changes in the barrier properties. Moreover, it was found that the Ce ions seems to be present in the cured films and are able to migrate towards the metal/coating interface thus providing a stabilization of the metal interface. [ABSTRACT FROM AUTHOR]

Studying the effect of longitudinal ultrasonic vibrations on the performance of incremental forming process of aluminum-1050 sheet is the main purpose of this paper. In this new technique, ultrasonic vibrations with high frequency and low amplitude are axially added to the movement of forming tool. To fulfill this purpose, a system was carefully devised. This system consists of different parts including a mechanism attached into the chuck of CNC machine to give rotary motion and also sent ultrasonic power to the vibratory tool. Straight groove test was performed, and various parameters including forming force and sheet formability were investigated in both conventional and ultrasonic-assisted incremental forming process. The achieved results show that ultrasonic assistance can increase formability and decrease forming force significantly. [ABSTRACT FROM AUTHOR]

This paper focuses on the development of a straight forward and inexpensive testing machine, and methodology for the characterization of materials in working conditions similar to those found in metal cutting. Special emphasis is given to the material rate dependence and to the assessing of the proposed methodology against conventional testing at very high rates of loading. The experimental results have demonstrated that rate-dependent hardness can be used to estimate flow stress at high rates of loading and that contact phenomena become even more prominent for severe monotonic deformation. [ABSTRACT FROM AUTHOR]

Silane sol-gel coatings have been widely studied as a potential strategy to protect aluminium and aluminium alloys components and were proved to be suitable both as a chemical conversion treatment alone and as a coupling agent between the underling substrate and an organic coating. Compared with many aluminium alloys, only little investigation was carried out on the application of sol-gel coatings on AA1XXX. Despite pure aluminiumshows lower mechanical resistance with respect to aluminiumalloys, however, the high thermal conductivity makes it suitable in a huge variety of applications, such as heat exchanger constructions as well as cooling systems. The present work is devoted to the study of the effect of the surface chemical pretreatment on the structural and corrosion protection properties of a hybrid sol-gel film. Different surface chemical treatments of the 1050 aluminium alloy prior sol-gel deposition were tested: alkaline etch, acidic passivation and boiling water immersion (to promote the formation of pseudo-boehmite). Films of 1 :1 molar ratio of GLYMO:MTES were obtained on AA1050 from a 5wt% solution in acidified water. The effect of the chemical surface treatment on the AA1050 substratewas investigated both in terms ofmorphology bymeans of scanning electron microscopy and in terms of surface chemistry by means of Fourier Transform Infrared Spectroscopy (FT-IR) exploiting attenuated total reflectance (ATR) geometry. The structure and the chemical properties of the different coatings were investigated by means of FT-IR. The characterization of the different protective coatings was carried out bymeans of electrochemical impedance spectroscopy measurements and potentiodynamic curves. [ABSTRACT FROM AUTHOR]

Friction StirWelding (FSW) is a solid-state welding process used for welding similar and dissimilar materials. FSW is especially suitable to join sheet Al alloys, and this technique allows different material couples to be welded continuously. In this study, 1050 Al alloys and commercially pure Cu were produced at three different tool rotation speeds (630, 1330, 2440 rpm) and three different tool traverse speeds (20, 30, 50 mm/min) with four different tool position (0, 1, 1.5, 2 mm) by friction stir welding. The influence of the welding parameters on the microstructure and mechanical properties of the joints was investigated. Tensile and bending tests and microhardness measurements were used to determine the mechanical properties. The microstructures of the weld zone were investigated by optical microscope and scanning electron microscope (SEM) and were analyzed in an energy dispersed spectrometer (EDS). Intermetallic phases were detected based on the X-ray diffraction (XRD) analysis results that evaluated the formation of phases in the weld zone. When the welding performance of the friction stir welded butt joints was evaluated, the maximum value obtained was 89.55% with a 1330 rpm tool rotational speed, 20 mm/min traverse speed and a 1 mm tool position configuration. The higher tensile strength is attributed to the dispersion strengthening of the fine Cu particles distributed over the Al material in the stir zone region. [ABSTRACT FROM AUTHOR]

In this work, the effects of grain size and dislocation density on strain hardening behavior of ultrafine grained (UFG) AA1050 produced by 9-cycle accumulative roll bonding (ARB) process were studied. Transmission electron microscopy (TEM) micrographs indicated that UFG structure with the average grain size of 270 ± 11 nm achieved after nine cycles of ARB. The dislocation density which was measured by microhardness value increased with an increase in the number of ARB cycles. The dislocation density increased from about 7 × 10 12 m −2 for annealed sample to above 2 × 10 13 m −2 after nine cycles ARB. Tensile tests results revealed that with increasing the number of ARB cycles, mechanical properties of the samples improved. The Hollomon analysis was used to investigate the strain hardening behavior of AA1050 samples. The results showed that the strain hardening exponent decreased with increasing the number of ARB cycles. All ARBed samples showed high strain hardening rate in initial stage of deformation, which increased with increasing dislocation density and grain refinement. [ABSTRACT FROM AUTHOR]

Many studies report that a very simple strategy to improve the corrosion resistance of aluminium is to promote the formation of a pseudo-boehmite (Al2O3·H2O) layer by a hydrothermal process (i.e. immersion in boiling water). In this work the effect on AA1050 panels of different durations of a boiling water treatment was investigated. In particular, the work is focussed on the corrosion protection properties of a sol-gel layer further applied to the treated aluminium panels and its interaction with the underlying pseudo-bohemite layer. Films consisting of 1:1 molar ratio of 3-glycidoxypropyltrime-thoxysilane (GLYMO) and methyltriethoxysilane (MTES) were applied on AA1050 plates. For this purpose, the effect of the different periods of immersion in boiling water was investigated in terms of morphology by means of scanning electron microscope, in terms of surface chemistry by means of FT-IR and in terms of electrochemical activity of the surface by exploiting electrochemical techniques such as polarisation curves. [ABSTRACT FROM AUTHOR]

Friction Stir Welding (FSW) is a solid state welding process used for welding similar and dissimilar materials. This welding technique allows welding of Aluminum alloys which present difficulties in fusion joining and allows different material couples to be welded continuously. In this study, 1050 aluminum alloy and commercially pure copper to increase heat input were produced at high rotation rate (2440 rev/min) with four different pin position (0-1-1.5-2 mm) and three different weld speeds (20-30-50 mm/min) by friction stir welding. The influence of welding parameters on microstructure and mechanical properties of the joints was investigated. Tensile and bending tests and microhardness measurements were used to determine of mechanical properties. Nugget zone microstructures were investigated by optical microscope and scanning electron microscope (SEM) and were analyzed in energy-dispersive X-ray spectroscopy (EDX). Depending on the XRD analysis results intermetallic phase was observed toform in the interfacial region. In the tensile test results, 83.55% weld performance was obtained in the friction stir welding merge of Al-Cu. [ABSTRACT FROM AUTHOR]

Friction Stir Welding (FSW) is a solid-state welding process used for welding similar and dissimilar materials. FSW is especially suitable to join sheet Al alloys, and this technique allows different material couples to be welded continuously. In this study, 1050 Al alloys and commercially pure Cu were produced at three different tool rotation speeds (630, 1330, 2440 rpm) and three different tool traverse speeds (20, 30, 50 mm/min) with four different tool position (0, 1, 1.5, 2 mm) by friction stir welding. The influence of the welding parameters on the microstructure and mechanical properties of the joints was investigated. Tensile and bending tests and microhardness measurements were used to determine the mechanical properties. The microstructures of the weld zone were investigated by optical microscope and scanning electron microscope (SEM) and were analyzed in an energy dispersed spectrometer (EDS). Intermetallic phases were detected based on the X-ray diffraction (XRD) analysis results that evaluated the formation of phases in the weld zone. When the welding performance of the friction stir welded butt joints was evaluated, the maximum value obtained was 89.55% with a 1330 rpm tool rotational speed, 20 mm/min traverse speed and a 1 mm tool position configuration. The higher tensile strength is attributed to the dispersion strengthening of the fine Cu particles distributed over the Al material in the stir zone region.

During processing from cast slab to thin gauge material, the AA1050 aluminium alloy proceeds through various stages of thermomechanical processing, with the conditions at each processing stage influencing the microstructure of the final coil. The reactivity of the material in defined chemical and electrochemical processes has been demonstrated as a useful method to describe variance in the microstructure and surface chemical properties of the aluminium. Various techniques have been employed to assess the reactivity of the surface, e.g. sodium hydroxide etching and open circuit potential measurements. Etching in hydrochloric acid was also carried out on samples that had been previously alkaline etched. The weight losses in both alkaline and acid solutions were measured, and the surface responses were examined and analysed using scanning electron microscopy and white light interferometry. Visible and measurable differences in the sample surfaces were observed. Finally, the novel state-of-the-art technique of in-SEM 3D electron tomography was used to characterize the near-surface microstructure in a way that has not previously been possible for such a representative volume. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In the present work, the robustness of an anodizing process was tested. Important anodizing parameters such as the anodizing potential, the dwell time at the anodizing potential, and the bath temperature were varied. The influence of the parameter variation on the microstructure of the oxide layers was investigated by SEM. It could be shown that the pore diameter as well as the layer thickness reacts very sensitively on the alternating parameters. The barrier layer thickness clearly depends on the anodizing voltage but is independent on the dwell time. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]