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1 – 10 of 93Arun M., Muthukumaran M. and Balasubramanian S.
Dissimilar materials found applications in the structural fields to withstand the different types of loads and provide multi-facet properties to the final structure. Aluminum…
Abstract
Purpose
Dissimilar materials found applications in the structural fields to withstand the different types of loads and provide multi-facet properties to the final structure. Aluminum alloy materials are mostly used in aerospace and marine industries to provide better strength and safeguard the material from severe environmental conditions. The purpose of this study is to develop new material with superior strength to challenge the severe environmental conditions.
Design/methodology/approach
In the present investigation, friction stir welding (FSW) dissimilar joints were prepared from AA6061 and AA5083 aluminum alloys, and the weld nugget (WN) was reinforced with hard reinforcement particles such as La2O3 and CeO2. The tribological and mechanical properties of the prepared materials were tested to analyze the suitability of material in the aerospace and marine environmental conditions.
Findings
The results showed that the AA6061–AA5083/La2O3 material exhibited better mechanical and tribological characteristics. The FSW dissimilar AA6061–AA5083/La2O3 material exhibited lower wear rate of 7.37 × 10−3 mm3/m and minimum friction coefficient of 0.31 compared to all other materials owing to the reinforcing effect of La2O3 particles and the fine grains formed by FSW process at WN region. Further, FSW dissimilar AA6061–AA5083/La2O3 material displayed a maximum tensile strength and hardness of 378 MPa and 118 HV, respectively, among all the other materials tested.
Originality/value
This work is original and novel in the field of materials science engineering focusing on tribological characteristics of friction stir welded dissimilar aluminum alloys by the reinforcing effect of hard particles such as La2O3 and CeO2.
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S.P. Venkatesan, K. Ramachandran, A. John Presin Kumar and Balamurugan G.M.
Aluminum alloy AA5083 is applicable in ship building, military, railway and industry because of its excellent properties like resistance to chemical and sea water attack. However…
Abstract
Purpose
Aluminum alloy AA5083 is applicable in ship building, military, railway and industry because of its excellent properties like resistance to chemical and sea water attack. However, its performance is affected by weak wear resistance. Hence, this should be solved to improve the performance of AA5083 alloy in the aforementioned fields. The purpose of this research is to enhance the wear properties of AA5083 alloy.
Design/methodology/approach
In this research, AA5083 alloy was reinforced with industrial wastes such as red mud and granite particles using stir casting method. Totally, four types of composites were fabricated, namely, AA5083/3 Wt.% red mud (C1), AA5083/3 Wt.% granite (C2), AA5083/1 Wt.% red mud-2Wt.% granite (C3) and AA5083/2 Wt.% red mud-1Wt.% granite (C4). Wear properties such as mass loss and coefficient of friction (COF) were analyzed for different wear parameters. Further, the mechanical properties like hardness and tensile strength were investigated.
Findings
Results showed that the inclusion of reinforcement particles improved the wear and mechanical properties of AA5083 alloy (C0). The C2 sample displayed the maximum hardness of 87 HV and tensile strength of 317 MPa owing to the inclusion of 3 Wt.% granite particles. Furthermore, the wear study results showed that the C2 sample displayed the minimum mass loss and COF. It was concluded from this research that C2 sample could be a good candidate to be applicable in marine, military, railway and industrial applications with improved performance.
Originality/value
This work is original as the industrial waste is used as reinforcements in the performance improvement of AA5083 aluminum alloy.
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Sivaselvan S., Natarajan M., Devadasan S.R. and Sivaram N.M.
Aluminum alloys are applicable in marine and aero fields. Alloys AA5083 and AA6061 are aluminum alloys with different chemical and physical properties. Combination of two…
Abstract
Purpose
Aluminum alloys are applicable in marine and aero fields. Alloys AA5083 and AA6061 are aluminum alloys with different chemical and physical properties. Combination of two dissimilar materials could result in enhanced strength. Generally, dissimilar aluminum alloy joint is made by friction stir welding (FSW) to achieve improved physical properties compared with the parent alloys. The purpose of this research is to develop a new FSW dissimilar material with enhanced properties using AA5083 and AA6061 alloys.
Design/methodology/approach
In this research, FSW joint was made for butt joint configuration using AA5083 and AA6061 aluminum alloys. Cylindrical pin with threaded profile was used to perform the joint. The tool tilting angle was maintained as constant, and the tool rotational speed and the welding speed were varied. Wear performance and mechanical strength of the joint were analyzed.
Findings
The results revealed that the increase of tool rotational speed led to poor wear performance, whereas increase of welding speed showed a better wear performance. Further, the prepared joint was analyzed for different wear parameters such as sliding velocity and applied load. The results displayed that the increase of sliding velocity exhibited low wear rate and the increase of load showed high wear rate.
Originality/value
This work is original and deals with the wear performance of AA5083–AA6061 joint at different tool rotational and welding speeds.
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Yesen Zhu, Zhe Liu, Zhenbo Qin, Mengyang Hou, Taoyong Hu and Quan Yuan
The purpose of this paper is to study the cavitation erosion stages of AA5083 by electrochemical noise (EN).
Abstract
Purpose
The purpose of this paper is to study the cavitation erosion stages of AA5083 by electrochemical noise (EN).
Design/methodology/approach
EN technology including noise resistance and fast Fourier transform were used to characterize the electrochemical process during the cavitation erosion process.
Findings
AA5083 suffers from uniform corrosion during the cavitation erosion process. The whole cavitation erosion process can be divided into three stages: incubation stage, acceleration stage and steady-state stage. EN signals showed obvious differences in different stages of cavitation erosion.
Originality/value
EN technique is a suitable method that can be used to study cavitation erosion mechanism and identify cavitation erosion stages.
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Vaira Vignesh Ramalingam, Padmanaban Ramasamy and Madhav Datta
The purpose of this study is to refine the microstructure and improve the corrosion behaviour of aluminium alloy AA5083 by subjecting it to friction stir processing (FSP).
Abstract
Purpose
The purpose of this study is to refine the microstructure and improve the corrosion behaviour of aluminium alloy AA5083 by subjecting it to friction stir processing (FSP).
Design/methodology/approach
FSP trials are conducted as per central composite design, by varying tool rotation speed, tool traverse speed and shoulder diameter at three levels. The microstructure is examined and the hardness is measured for both the base material and the processed workpieces. The corrosion behaviour of the base material and processed workpieces is studied using potentiodynamic polarization technique for three different testing temperatures, and the corrosion current and corrosion rate are calculated.
Findings
The results reveal that FSP refined the grains, dispersed secondary phases, increased the hardness and improved the corrosion resistance of most of the friction stir processed specimens than the base material at all the three testing temperatures. Grain refinement and fine dispersion of ß phase improves the hardness and corrosion resistance of most of the FSPed specimens. However partial dissolution of ß phase decreases the hardness in some of the specimens. Most of the FSPed specimens displayed more positive potential than the base material at all the testing temperatures representing a higher nobility than the base material, as a result of fine dispersion of secondary phase particles in the matrix. Large pits formed on the surface of the base specimen indicating a higher corrosion rate at all three testing temperatures. The SEM image of FSPed specimens reveals the occurrence of very few pits and minimal corrosion products on the surface, which indicates lower corrosion rate.
Originality/value
The corrosion mechanism of the friction stir-processed AA5083 specimens is found to be a combination of activation and concentration polarization.
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K. Jafarzadeh, T. Shahrabi, S.M.M. Hadavi and M.G. Hosseini
The paper aims to focus on the recognition of corrosion product morphologies of AA5083‐H321 corroding aluminum‐magnesium alloys used in the manufacture of aluminum high speed…
Abstract
Purpose
The paper aims to focus on the recognition of corrosion product morphologies of AA5083‐H321 corroding aluminum‐magnesium alloys used in the manufacture of aluminum high speed boats and submarines during flow induced corrosion in seawater.
Design/methodology/approach
All experiments were conducted in a 3.5 percent NaCl solution as the simulated marine environment. Hydrodynamic conditions were created by an rotating cylinder electrode (RCE) system. Morphological characterization of the surface was undertaken using SEM and EDAX techniques. Cyclic polarization tests were used to determine the electrochemical behavior of the alloy.
Findings
The results obtained reveal that the pit density on the sample surface increased with increasing the rotation speed. The enhanced flow condition also enhanced the tendency for intermetallic particles, including submicron size Al(Mg,Mn) inclusions, to promote pitting corrosion of the alloy. An interesting result was that crystallographic pitting occurred at rotation speeds greater than 5 m/s.
Practical implications
In the selection of corrosion control methods for high speed aluminum‐hulled boats, control of erosion corrosion was determined to be more important than any other form of corrosion.
Originality/value
Provides information about the contribution of mechanical and electrochemical corrosion phenomena in corrosion of high speed aluminum boats under hydrodynamic conditions. Characterization of new intermetallic particles in aluminum‐magnesium alloys that can promote pitting during flow induced corrosion in marine environments. Provides new information about the origin of crystallographic pitting attack on aluminum.
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Amit Rana, Sandeep Deshwal, Rajesh and Naveen Hooda
The weld joint mechanical properties of friction stir welding (FSW) are majorly reliant on different input parameters of the FSW machine. The study and optmization of these…
Abstract
Purpose
The weld joint mechanical properties of friction stir welding (FSW) are majorly reliant on different input parameters of the FSW machine. The study and optmization of these parameters is uttermost requirement and aim of this study to increase the suitability of FSW in different manufacturing industries. Hence, the input parameters are optimized through different soft computing methods to increase the considered objective in this study.
Design/methodology/approach
In this research, ultimate tensile strength (UTS), yield strength (YS) and elongation (EL) of FSW prepared butt joints of AA6061 and AA5083 Aluminium alloys materials are investigated as per American Society for Testing and Materials (ASTM E8-M04) standard. The FSW joints were prepared by changing the three input process parameters. To develop experimental run order design matrix, rotatable central composite design strategy was used. Furthermore, genetic algorithm (GA) in combination (Hybrid) with response surface methodology (RSM), artificial neural network (ANN), i.e. RSM-GA, ANN-GA, is exercised to optimize the considered process parameters.
Findings
The maximum value of UTS, YS and EL of test specimens on universal testing machine was measured as 264 MPa, 204 MPa and 14.41%, respectively. The most optimized results (UTS = 269.544 MPa, YS = 211.121 MPa and EL = 17.127%) are obtained with ANN-GA for the considered objectives.
Originality/value
The optimization of input parameters to increase the output objective values using hybrid soft computing techniques is unique in this research paper. The outcomes of this study will help the FSW using manufacturing industries to choose the best optimized parameters set for FSW prepared butt joint with improved mechanical properties.
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Yanming Xia, Dejing Zhou, Zhiming Gao and Wenbin Hu
This paper aims to study the effect of Hg2+ on the corrosion behavior of Al–2%Zn coatings on AA5083 in 3.5 Wt.% NaCl solution.
Abstract
Purpose
This paper aims to study the effect of Hg2+ on the corrosion behavior of Al–2%Zn coatings on AA5083 in 3.5 Wt.% NaCl solution.
Design/methodology/approach
Potentiodynamic polarization and electrochemical impedance spectroscopy are used to investigate the effect of Hg2+ on the corrosion behavior. The surface and cross-sectional morphology are characterized by scanning electron microscopy and energy dispersive spectroscopy (EDS) to further reveal the corrosion mechanism of Hg2+.
Findings
The results show that the corrosion behavior of the coating changes significantly as the concentration of Hg2+ increases from 5 to 30 μg/L. The corrosion production film can inhibit the corrosion process when Hg2+ concentration is in the range of 0.5–5 μg/L, while Hg2+ can promote the corrosion process significantly when its concentration reaches to 30 μg/L. The generation rate of dense oxide film on the coating surface is faster than dissolution rate when the concentration of Hg2+ is in the range of 0–5 μg/L, which makes the coating “self-healing” and thus slightly slows down the corrosion rate. The EDS analysis shows that excessive Hg2+ are preferentially deposited at locations with inhomogeneous electrochemical properties, which in turn accelerates corrosion.
Originality/value
The corrosion resistance of Al-based coatings is significantly affected by Hg2+ in seawater. Thus, it is important to explain the corrosion mechanism of Al–2%Zn coatings under the combined effect of Hg2+ and Cl− in 3.5 Wt.% NaCl solution.
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M. Grujicic, R Yavari, S. Ramaswami, J Snipes and R Galgalikar
Friction stir welding (FSW) butt-joining involving the use of a dissimilar filler metal insert between the retreating and advancing portions of the workpiece is investigated…
Abstract
Purpose
Friction stir welding (FSW) butt-joining involving the use of a dissimilar filler metal insert between the retreating and advancing portions of the workpiece is investigated computationally using a combined Eulerian-Lagrangian (CEL) finite element analysis (FEA). The emphasis of the computational analysis was placed on the understanding of the inter-material mixing and weld-flaw formation during a dissimilar-material FSW process. The paper aims to discuss these issues.
Design/methodology/approach
The FEA employed is of a two-way thermo-mechanical character (i.e. frictional-sliding/plastic-work dissipation was taken to act as a heat source in the energy conservation equation), while temperature is allowed to affect mechanical aspects of the model through temperature-dependent material properties. Within the analysis, the workpiece and the filler-metal insert are treated as different materials within the Eulerian subdomain, while the tool was treated as a conventional Lagrangian subdomain. The use of the CEL formulation within the workpiece insert helped avoid numerical difficulties associated with excessive Lagrangian element distortion.
Findings
The results obtained revealed that, in order to obtain flaw-free FSW joints with properly mixed filler and base materials, process parameters including the location of the tool relative to the centerline of the weld must be selected judiciously.
Originality/value
To the authors’ knowledge, the present work is the first reported attempt to simulate FSW of dissimilar materials.
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Elias P. Koumoulos, Costas A. Charitidis, Nikolaos M. Daniolos and Dimitrios I. Pantelis
The purpose of this paper is to determine if the nanoindentation technique is a reliable method and whether it can be used to measure the surface hardness (H) in friction stir…
Abstract
Purpose
The purpose of this paper is to determine if the nanoindentation technique is a reliable method and whether it can be used to measure the surface hardness (H) in friction stir welded aluminum alloys. In order to test the reliability of nanoindentation technique, nanohardness values for friction stir welded aluminum alloys were compared to microhardness values. Additionally, the onset of plasticity (yielding) is investigated.
Design/methodology/approach
Nanoindentation experiments were performed for the determination of onset on plasticity (yielding) and comparison of local mechanical properties of both welded alloys. In order to test the reliability of nanoindentation technique, nanohardness values for friction stir welded AA6082 were compared to microhardness values. The specimen was tested using two different instruments – a Vickers microhardness tester and a nanoindenter tester for fine scale evaluation of H.
Findings
The results of this study indicate that nanohardness values with a Berkovich indenter reliably correlate with Vickers microhardness values. Nanoindentation technique can provide reliable results for analyzing friction stir welded aluminum alloys. The welding process definitely affects the material mechanical properties.
Originality/value
Microhardness and nanohardness obtained values can be correlated carefully, regarding the similarities and the differences of the two above mentioned techniques.
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