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1 – 10 of 100Serkan Büyükdoğan, Süleyman Gündüz and Mustafa Türkmen
– The paper aims to provide new observations about static strain ageing in aluminium (Al) alloys which are widely used in structural applications.
Abstract
Purpose
The paper aims to provide new observations about static strain ageing in aluminium (Al) alloys which are widely used in structural applications.
Design/methodology/approach
The present work aims to provide theoretical and practical information to industries or researchers who may be interested in the effect of static strain ageing on mechanical properties of Al alloys. The data are sorted into the following sections: introduction, materials and experimental procedure, results and discussion and conclusions.
Findings
Tensile strength, proof strength (0.2 per cent) and percentage elongation measurement were used to investigate the effect of strain ageing on the mechanical properties. Wear tests were performed by sliding the pin specimens, which were prepared from as-received, solution heat-treated, deformed and undeformed specimens after ageing, on high-speed tool steel (64 HRC). It is concluded that the variations in ageing time improved the strength and wear resistance of the 6063 Al alloy; however, a plastically deformed solution-treated alloy has higher strength and wear resistance than undeformed specimens for different ageing times at 180°C.
Practical implications
A very useful source of information for industries using or planning to produce Al alloys.
Originality/value
This paper fulfils an identified resource need and offers practical help to the industries.
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Keywords
Abstract
Purpose
The purpose of this paper is to improve the corrosion resistance of anodized 6063 Al alloy inertial air–water separator by means of silane technology and to investigate the effect of corrosion-generated surface roughness changes on aerodynamic performance.
Design/methodology/approach
The BTSE-KH560 double-layer silane film treatment technique is used to close micropores on the anodic oxide film surface. The microstructure of the coating is observed by scanning electron microscopy, the coating structure of the specimens is determined by X-ray diffraction (XPS) and the corrosion resistance is determined by electrochemical and salt-spray tests. Computational fluid dynamics is also used to calculate the effect of roughness and analyse the change in separator performance.
Findings
The silane film deposited on the surface of the anodic oxide film acts as a good seal against microporous defects on the surface of the anodic oxide film and reduces the surface roughness. Electrochemical and salt-spray tests show that the silane film improved the corrosion resistance of the anodized film. The roughness produced by the corrosion deteriorates the performance of the separator.
Originality/value
The porous structure of the anodized coating makes it easier for corrosive ions to enter the substrate and cause pitting corrosion. Therefore, in this study, the corrosion behaviour of the coating in the marine environment and its effect on aerodynamic performance are investigated using a BTSE-KH560 double-layer silane coating with a sealing effect.
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A. Al Mayouf, L. Al Juhaiman and A. Suhaybani
This paper seeks to study the corrosion rate (CR) of Al 6063 in aqueous solutions containing food additives, namely ascorbic, citric and tartaric acids with/without chloride ions.
Abstract
Purpose
This paper seeks to study the corrosion rate (CR) of Al 6063 in aqueous solutions containing food additives, namely ascorbic, citric and tartaric acids with/without chloride ions.
Design/methodology/approach
Chemical and electrochemical measurements were used to study the CR of Al 6063 in aerated aqueous solutions. Chemical measurements include weight loss (WL) and atomic absorption (AA). The surface morphology of Al 6063 was studied using scanning electron microscope connected with energy dispersion X‐Ray (EDX). Electrochemical measurements were made using a potentiostat/galvanostat; the effect of pH, temperature and immersion time was studied.
Findings
AA gave comparable results to that of WL. EDX results showed the depletion of Mg and Fe from the Al 6063 to carboxylic acid solutions w/without NaCl. From electrochemical measurements, it was found that addition of chloride ions to carboxylic acids increased the CR of Al 6063 especially at low pH and high temperatures but it reduced the CR at long immersion times.
Practical implications
Aluminum (Al) is now known to be a neurotoxin agent yet Al cook wares are widely used in different countries. The acids used in this study are food additives which implies that the Al cook wares may corrode in food containing these acids and other carboxylic acids depending on pH, temperature and the presence of other additives.
Originality/value
AA gave comparable results to that of WL, which shows that it may be used to evaluate leaching metal ions in μg levels or less in corrosion measurements.
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Bekir Yilbas, A.F.M. Arif and Sohail Akhtar
It has been observed from the history of failed dies used in local extrusion industry that after certain press cycles, severe die damage occurs by using more number of in‐house…
Abstract
Purpose
It has been observed from the history of failed dies used in local extrusion industry that after certain press cycles, severe die damage occurs by using more number of in‐house recycled billets. The purpose of this paper is to focus on the effect of billet quality on the extrusion die service life, based on using microstructural and finite element analyses.
Design/methodology/approach
Numerical solution of stress distribution in extrusion die using microstructural and finite element analyses.
Findings
Simulation results demonstrate that extrusion die experiences high stresses and strains at critical locations by running secondary billets. Billet deformation behavior also shows that secondary billet has more resistance to flow during extrusion cycle, which results in such high stresses and strains in the die.
Research limitations/implications
The study includes a particular die used to extrude the aluminum alloy billets. It may need to generalized including materials other than aluminum alloy.
Practical implications
The findings are original and believed to be useful for engineers working in the extrusion dies. Since it is shown that secondary billets (recycled billets) have more resistance to flow in the dye, a care should be taken when estimating the die life for the practical applications.
Originality/value
It is an original work. It deals with the comparison of new and recycled billets's performance in terms of stress formation in the die during the extrusion cycle.
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M.P. Jenarthanan, A. Ram Prakash and R. Jeyapaul
The purpose of this paper is to develop a mathematical model for metal removal rate and surface roughness through Taguchi method and analyse the influence of the individual input…
Abstract
Purpose
The purpose of this paper is to develop a mathematical model for metal removal rate and surface roughness through Taguchi method and analyse the influence of the individual input machining parameters (cutting speed, feed rate, helix angle, depth of cut and wt% on the responses in milling of aluminium-titanium diboride metal matrix composite (MMC) with solid carbide end mill cutter coated with nano-crystals.
Design/methodology/approach
Taguchi OA is used to optimise the material removal rate (MRR) and Surface Roughness by developing a mathematical model. End Milling is used to create slots by combining various input parameters. Five factors, three-level Taguchi method is employed to carry out the experimental investigation. Fuzzy logic is used to find the optimal cutting factors for surface roughness (Ra) and MRR. The factors considered were weight percentage of TiB2, cutting speed, depth of cut and feed rate. The plan for the experiments and analysis was based on the Taguchi L27 orthogonal array with five factors and three levels. MINITAB 17 software is used for regression, S/N ratio and analysis of variance. MATLAB 7.10.0 is used to perform the fuzzy logics systems.
Findings
Using fuzzy logics, multi-response performance index is generated, with which the authors can identify the correct combination of input parameters to get higher MRR and lower surface roughness value with the chosen range with 95 per cent confidence intervals. Using such a model, remarkable savings in time and cost can be obtained.
Originality/value
Machinability characteristics in Al-TiB2 MMC based on the Taguchi method with fuzzy logic has not been analysed previously.
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To discuss the effects of metal matrix composite (MMC) journal structure on the pressure distribution and, consequently, on the load‐carrying capacity of the bearing are predicted…
Abstract
Purpose
To discuss the effects of metal matrix composite (MMC) journal structure on the pressure distribution and, consequently, on the load‐carrying capacity of the bearing are predicted using feed forward architecture of neurons.
Design/methodology/approach
The inputs to the networks are the collection of experimental data. These data are used to train the network using the Batch Back‐prop, Online Back‐prop and Quickprop algorithms.
Findings
The neural network (NN) model outperforms the available experimental model in predicting the pressure as well as the load‐carrying capacity.
Research limitations/implications
The experiment specimens used in this study have been made of MMC with aluminum based reinforced with SiC ceramic particles, using the stir casting technique. Various composite journal structures can be investigated.
Practical implications
The simulation results suggest that the neural predictor would be used as a predictor for possible experimental applications on modelling journal bearing system.
Originality/value
This paper discusses a new modelling scheme known as artificial NNs. An experimental and a NN approach have been employed for analysing MMC journal structure for hydrodynamic journal bearings and their effects on the system performance.
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Payman Sahbah Ahmed, Ava A.K. Mohammed and Fakhir Aziz Rasul Rozhbiany
The purpose of this study is to get benefits from manufacturing harmful wastes is by using them as a reinforcement with epoxy matrix composite materials to improve the damping…
Abstract
Purpose
The purpose of this study is to get benefits from manufacturing harmful wastes is by using them as a reinforcement with epoxy matrix composite materials to improve the damping characteristics in applications such as machine bases, rockets, satellites, missiles, navigation equipment and aircraft as large structures, and electronics as such small structures. Vibration causes damaging strains in these components.
Design/methodology/approach
By adding machining chips with weight percentages of 5, 10, 15 and 20 Wt.%, with three different chip lengths added for each percentage (0.6, 0.8 and 1.18 mm), the three-point bending and damping characteristics tests are utilized to examine how manufacturing waste impacts the mechanical properties. Following that, the optimal lengths and the chip-to-epoxy ratio are determined. The chip dispersion and homogeneity are assessed using a field emission scanning electron microscope.
Findings
Waste copper alloys can be used to enhance the vibration-dampening properties of epoxy resin. The interface and bonding between the resin and the chip are crucial for enhancing the damping capabilities of epoxy. Controlling the flexural modulus by altering the chip size and quantity can change the damping characteristics because the two variables are inversely related. The critical chip size is 0.8 mm, below which smaller chips cannot evenly transfer, and disperse the vibration force to the epoxy matrix and larger chips may shatter and fracture.
Originality/value
The main source of problems in machine tools, aircraft and vehicle manufacturing is vibrations generated in the structures. These components suffer harmful strains due to vibration. Damping can be added to these structures to get over these problems. The distribution of energy stored as a result of oscillatory mobility is known as damping. To optimize the serving lifetime of a dynamic suit, this is one of the most important design elements. The use of composites in construction is a modern method of improving a structure's damping capacity. Additionally, it has been demonstrated that composites offer better stiffness, strength, fatigue resistance and corrosion resistance. This research aims to reduce the vibration effect by using copper alloy wastes as dampers.
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Shaik Heruthunnisa and Chandra Mohana Reddy B.
The purpose of this paper is to study formability, tensile properties, dislocation density and surface roughness of incrementally deformed Ti–6Al–4V alloy sheets during…
Abstract
Purpose
The purpose of this paper is to study formability, tensile properties, dislocation density and surface roughness of incrementally deformed Ti–6Al–4V alloy sheets during single-point incremental forming (SPIF) and multi-point incremental forming (MPIF) process. The development of corrosion pits in 3.5% NaCl solution has also been studied during SPIF and MPIF processes.
Design/methodology/approach
In this study, the formability, tensile properties, dislocation density, surface roughness and corrosion behaviour of deformed Ti–6Al–4V alloy sheets were studied. A potentio-dynamic polarization (PDP) study was conducted to study the corrosion behaviour of Ti–6Al–4V alloy samples during SPIF and MPIF processes and the results were also compared with base material (BM) in 3.5% NaCl solution. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses were carried out to study the corrosion morphology and dislocation densities of deformed samples.
Findings
The deformed Ti–6Al–4V alloy sheets obtained higher plastic deformation, high tensile strength, good surface roughness and good corrosion resistance during MPIF process when compared with SPIF process.
Research limitations/implications
It has been concluded that the maximum strain and good corrosion resistance have been achieved with MPIF process, which in turn increases the plastic deformation as compared with BM.
Practical implications
This study discussed the formability, tensile properties, surface roughness and corrosion behaviour of deformed Ti–6Al –4V alloy sheets during incremental sheet forming (ISF) process.
Social implications
This study is useful in the field of medical, industrial and automobile applications.
Originality/value
The Ti–6Al–4V alloy is deformed using MPIF process, achieving better formability, tensile strength, good surface roughness and corrosion rate, and the same is evidenced in forming limit diagrams (FLDs) and PDP curves.
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Venkateshwar Reddy Pathapalli, Veerabhadra Reddy Basam, Suresh Kumar Gudimetta and Madhava Reddy Koppula
Nowadays, the applications of metal matrix composites are tremendously increasing in engineering fields. Consequently, the demand for precise machining of composites has also…
Abstract
Purpose
Nowadays, the applications of metal matrix composites are tremendously increasing in engineering fields. Consequently, the demand for precise machining of composites has also grown enormously. The purpose of this paper is to reduce production cost and simultaneously improve desired product quality through optimal parameter setting using WASPAS and MOORA.
Design/methodology/approach
Metal matrix composites were fabricated using stir casting process, with aluminum 6063 as matrix and titanium carbide as reinforcement. Fabricated composite samples were machined on medium duty lathe using cemented carbide tool. All the experiments were carried out based on Box–Behnken design. Comparison of multi objective optimization based on ratio analysis and weighted aggregated sum product assessment in optimizing four parameters, namely, “cutting speed,” “feed rate,” “depth of cut” and “reinforcement weight percent of composite samples”; evaluating their influence on material removal rate, cutting force and surface roughness were carried out.
Findings
The output achieved by both MOORA and WASPAS are in similar MCDM) techniques in the selection of machining parameters.
Practical implications
The results obtained in the present paper will be helpful for decision makers in manufacturing industries, who work in metal cutting area, to select the suitable levels for the parameters by implementing the MCDM techniques.
Originality/value
The novelty of this paper is making an attempt to select better MCDM technique based on the comparison of results obtained for the individual technique.
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Friction stir welding (FSW) is considered an environmentally sound process compared to traditional fusion welding processes. It is a complex process in which various parameters…
Abstract
Purpose
Friction stir welding (FSW) is considered an environmentally sound process compared to traditional fusion welding processes. It is a complex process in which various parameters influence weld strength. Therefore, it is essential to identify the best parameter settings for achieving the desired weld quality. This paper aims to investigate the multi-response optimization of process parameters of the FSWed 6061-T6 aluminum (Al) alloy.
Design/methodology/approach
The input process parameters related to FSW have been sorted out from a detailed literature survey. The properties of weldments such as yield strength, ultimate tensile strength, percentage elongation and microhardness have been used to evaluate weld quality. The process parameters have been optimized using the Taguchi-based grey relational analysis (GRA) methodology. Taguchi L16 orthogonal array has been considered to design the experiments. The effect of input parameters on output responses was also determined by the analysis of variance (ANOVA) method. Finally, to corroborate the results, a confirmatory experiment was carried out using the optimized parameters from the study.
Findings
The ANOVA result indicates that the tool rotation speed was the most significant parameter followed by tool pin profile and welding speed. From the confirmation test, it was observed that the optimum FSW process parameters predicted by the Taguchi method improved the grey relational grade by 13.52%. The experimental result also revealed that the Taguchi-based GRA method is feasible in finding solutions to multi-response optimization problems in the FSW process.
Originality/value
The present study is unique in the multi-response optimization of FSWed 6061-T6 Al alloy using the Taguchi and GRA methodology. The weld material having better mechanical properties is essential for the material industry.
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