G. Yoganjaneyulu, Y. Phaneendra, V.V. Ravikumar and C. Sathiya Narayanan
The purpose of this paper is to investigate the void coalescence and corrosion behaviour of titanium Grade 4 sheets during single point incremental forming (SPIF) process with…
Abstract
Purpose
The purpose of this paper is to investigate the void coalescence and corrosion behaviour of titanium Grade 4 sheets during single point incremental forming (SPIF) process with various spindle rotational speeds. The development of corrosion pits in 3.5 (%) NaCl solution has also been studied during SPIF process.
Design/methodology/approach
In this current research work, the void coalescence analysis and corrosion behaviour of titanium Grade 4 specimens were studied. A potentio-dynamic polarization (PDP) study was conducted to investigate the corrosion behaviour of titanium Grade 4 processed samples with various spindle speeds in 3.5 (%) NaCl solution. The scanning electron microscope and transmission electron microscope analysis was carried out to study the fracture behaviour and corrosion morphology of processed samples.
Findings
The titanium Grade 4 sheets obtained better formability and corrosion resistance by increasing the CNC spindle rotational speeds. In fact that, the significant plastic deformation affects the corrosion rate with various spindle speeds were recorded.
Originality/value
The spindle rotational speeds and vertical step depths increases then the titanium Grade 4 sheets showed better formability, void coalescence and corrosion behaviour as the same is evidenced in forming limit diagram and PDP curves.
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G. Yoganjaneyulu, V.V. Ravikumar and C. Sathiya Narayanan
The purpose of this paper is to investigate the strain distribution, stress-based fracture limit and corrosion behaviour of titanium Grade 2 sheets during single point incremental…
Abstract
Purpose
The purpose of this paper is to investigate the strain distribution, stress-based fracture limit and corrosion behaviour of titanium Grade 2 sheets during single point incremental forming (SPIF) process, with various computerized numerical control (CNC) spindle rotational speeds and step depths. The development of corrosion pits in 3.5 (%) NaCl solution has also been studied during the SPIF process.
Design/methodology/approach
A potentiodynamic polarization (PDP) study was performed to investigate the corrosion behaviour of titanium Grade 2 deformed samples, with various spindle rotational speeds in 3.5 (%) NaCl solution. The scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis was carried out to study the fracture behaviour, dislocation densities and corrosion morphology of deformed samples.
Findings
The titanium Grade 2 sheets exhibited better strain distribution, fracture limit and corrosion resistance by increasing the CNC spindle rotational speeds, tool diameters and vertical step depths (VSD). It was recorded that varying the spindle speed affected plastic deformation which in turn affected corrosion rate.
Research limitations/implications
In this study, poor corrosion rate was observed for the as-received condition, and better corrosion rate was achieved at maximum speed of 600 rpm and 0.6 mm of VSD in the deformed sheet. This indicates that corrosion rate improved with increase in the plastic deformation. The EDS analysis report of corroded surface revealed the composition to be mainly of titanium and oxides.
Practical implications
This study discusses the strain distribution, stress-based fracture limit and corrosion behaviour by using titanium Grade 2 sheets during SPIF process.
Social implications
This study is useful in the field of automobile and industrial applications.
Originality/value
With an increase in the spindle rotational speeds and VSD, the titanium Grade 2 sheets showed better strain distribution, fracture limit and corrosion behaviour; the same is evidenced in fracture limit curve and PDP curves.
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The purpose of this paper is to study the corrosion behaviour of Al-12Zn-3Mg-2.5Cu alloy by cast, precipitation hardening and non-isothermal step rolling cum cold/cryo rolling…
Abstract
Purpose
The purpose of this paper is to study the corrosion behaviour of Al-12Zn-3Mg-2.5Cu alloy by cast, precipitation hardening and non-isothermal step rolling cum cold/cryo rolling (−80 and −196°C) in 3.5 per cent NaCl solution.
Design/methodology/approach
Aluminium alloy with high alloying concentration (Zn: 12 per cent, Mg: 3 per cent, Cu: 2.5 per cent) was prepared by squeeze casting method with controlled process parameters. The cast alloy was solution treated at 450°C for 24 h and aged at 120°C with varying time intervals. Initially, the alloy also underwent non-isothermal step rolling from 6 mm to 3 mm at 400-100°C at the step of 100ºC with 15% reduction in thickness. Non-isothermal rolled alloy (3 mm thickness) was the starting material for further rolling at three different temperatures, such as room temperature, −80 and −190°C with 85 per cent reduction. Microstructural evolution during precipitation and thermo-mechanical processing was studied with the help of optical microscopy and electron microscopy. A potentio-dynamic polarization study was performed to evaluate the corrosion behaviour of Al-12Zn-3Mg-2.5Cu alloy processed in different conditions in 3.5 per cent NaCl solution.
Findings
There is a distinct evidence that the alloy exhibits varying corrosion resistance by changing its structural features. In fact, the alloy with ultra-fine grained structure exhibits good corrosion resistance than that of alloy in cast. This is attributed to a greater grain boundary region with high dislocation density, and plastic strain adversely affects the corrosion resistance.
Originality/value
The results obtained by this investigation help in understanding the effect of precipitation hardening and non-isothermal step rolling cum cold/cryo rolling (−80 and −196°C) on corrosion behaviour.
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K. Sivaprasad, V. Swarnalatha, V.V. Ravikumar and V. Muthupandi
The purpose of this paper is to study the corrosion behavior of as‐cryorolled and cryorolled‐short annealed commercially pure aluminum (CP‐Al) in 3.5 percent NaCl solution.
Abstract
Purpose
The purpose of this paper is to study the corrosion behavior of as‐cryorolled and cryorolled‐short annealed commercially pure aluminum (CP‐Al) in 3.5 percent NaCl solution.
Design/methodology/approach
Cast and homogenized CP‐Al samples are cryorolled from 7 to 0.7 mm at −80°C. Samples are short annealed at 125, 150 and 175°C for 3 min. Transmission electron microscope studies are performed to understand the effect of cryorolling and short annealing on microstructure. Corrosion behavior of these samples in 3.5 percent NaCl solution is evaluated by potentiodynamic polarization studies.
Findings
Though cryorolling adversely affects corrosion resistance of CP‐Al, short annealing can restore the loss in corrosion resistance partially by the recovery process. The extent of restoration of loss in corrosion resistance by short annealing is influenced by the texture.
Originality/value
The results obtained by this investigation help in understanding the effect of cryorolling and short annealing on corrosion behavior of CP‐Al.
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M.C. Raju, S.V.K. Varma and A.J. Chamkha
The purpose of this paper is to present an analytical study for a problem of unsteady free convection boundary layer flow past a periodically accelerated vertical plate with…
Abstract
Purpose
The purpose of this paper is to present an analytical study for a problem of unsteady free convection boundary layer flow past a periodically accelerated vertical plate with Newtonian heating (NH).
Design/methodology/approach
The equations governing the flow are studied in the closed form by using the Laplace transform technique. The effects of various physical parameters are studied through graphs and the expressions for skin friction, Nusselt number and Sherwood number are also derived and discussed numerically.
Findings
It is observed that velocity, concentration and skin friction decrease with the increasing values of Sc whereas temperature distribution decreases in the increase in Pr in the presence of NH.
Research limitations/implications
This study is limited to a Newtonian fluid. This can be extended for non-Newtonian fluids.
Practical implications
Heat and mass transfer frequently occurs in chemically processed industries, distribution of temperature and moisture over agricultural fields, dispersion of fog and environment pollution and polymer production.
Social implications
Free convection flow of coupled heat and mass transfer occurs due to the temperature and concentration differences in the fluid as a result of driving forces. For example, in atmospheric flows, thermal convection resulting from heating of the earth by sunlight is affected differences in water vapor concentration.
Originality/value
The authors have studied heat and mass transfer effects on unsteady free convection boundary layer flow past a periodically accelerated vertical surface with NH, where the heat transfer rate from the bounding surface with a finite heat capacity is proportional to the local surface temperature, and which is usually termed as conjugate convective flow. The equations governing the flow are studied in the closed form by using the Laplace transform technique. The effects of various physical parameters are studied through graphs and the expression for skin friction also derived and discussed.
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Xiaobo Wang, Wen Zhan and Boyi Gui
The purpose of this paper is to develop a chrome-free and phosphorus-free chemical conversion coating with good corrosion resistance, a novel chemical conversion coating was…
Abstract
Purpose
The purpose of this paper is to develop a chrome-free and phosphorus-free chemical conversion coating with good corrosion resistance, a novel chemical conversion coating was prepared by adding cerium nitrate hexahydrate and salicylic acid in the treatment solution containing titanium/zirconium ions on 6061 aluminum alloy.
Design/methodology/approach
Compared with the AA6061 aluminum alloy matrix, the self-corrosion potential of the conversion coating is significantly positively shifted, the self-corrosion current density is greatly reduced and its corrosion resistance is significantly improved. Morphology and composition of the conversion coatings were observed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The microdomain structure of conversion coatings at different formation stages was analyzed by electron probe microanalyzer.
Findings
An optimized preparation technique of titanium–zirconium chemical conversion coating for AA6061 aluminum alloy is obtained: H2TiF6 4 mL/L, H2ZrF6 0.4 mL/L, salicylic acid 0.35 g/L, Ce(NO3)3·6H2O 0.14 g/L, reaction temperature 30°C, reaction time 120 s and pH 4.0.
Originality/value
The coating forms on the Al(Fe)Si intermetallic compound, and Ce3+ is preferentially adsorbed on the intermetallic compound. The hydrolysis of Ce3+ causes the local pH of the solution to decrease, which promotes matrix dissolution and charge migration. As the microanode/microcathode reaction occurs, the local pH of the solution increases, and Al2O3/ZrO2/TiO2 begins to deposit on the surface of the metal substrate.
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V.P. Sakthivel, R. Bhuvaneswari and S. Subramanian
The purpose of this paper is to present the application of an adaptive bacterial foraging (BF) algorithm for the design optimization of an energy efficient induction motor.
Abstract
Purpose
The purpose of this paper is to present the application of an adaptive bacterial foraging (BF) algorithm for the design optimization of an energy efficient induction motor.
Design/methodology/approach
The induction motor design problem is formulated as a mixed integer nonlinear optimization problem. A set of nine independent variables is selected, and to make the machine feasible and practically acceptable, six constraints are imposed on the design. Two different objective functions are considered, namely, the annual active material cost, and the sum of the annual active material cost, annual cost of the active power loss of the motor and annual energy cost required to supply such power loss. A new adaptive BF algorithm is used for solving the optimization problem. A generic penalty function method, which does not require any penalty coefficient, is employed for constraint handling.
Findings
The adaptive BF algorithm is validated for two sample motors and benchmarked with the genetic algorithm, particle swarm optimization, simple BF algorithm, and conventional design methods. The results show that the proposed algorithm outperforms the other methods in both the solution quality and convergence rate. The annual cost of the induction motor is remarkably reduced when designed on the basis of minimizing its annual total cost, instead of minimizing its material cost only.
Originality/value
To the best of the knowledge, none of the existing work has applied the BF algorithms for electrical machine design problems. Therefore, the solution to this problem constitutes the main contribution of the paper. According to the huge number of induction motors operating all over the world, the BF techniques used in their design, on minimum annual cost basis, will lead to a tremendous saving in global energy consumption.
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Amir A. Abdulmuhsin, Hayder Dhahir Hussein, Hadi AL-Abrrow, Ra’ed Masa’deh and Abeer F. Alkhwaldi
In this research, we seek to understand the effects of artificial intelligence (AI) and knowledge management (KM) processes in enhancing proactive green innovation (PGI) within…
Abstract
Purpose
In this research, we seek to understand the effects of artificial intelligence (AI) and knowledge management (KM) processes in enhancing proactive green innovation (PGI) within oil and gas organizations. It also aims to investigate the moderator role of trust and sustainability in these relationships.
Design/methodology/approach
This paper employs a quantitative analysis. Surveys have been gathered from the middle-line managers of twenty-four oil and gas government organizations to evaluate the perceptions of the managers towards AI, KM processes, trust, sustainability measures and proactive measures toward green innovation. Analytical and statistical tools that were employed in this study, including structural equation modeling with SmartPLSv3.9, have been used to analyze the data and to examine the measurement and structural models of this study.
Findings
The study results reveal a significant and positive impact of AI utilization, KM processes and PGI within oil and gas organizations. Furthermore, trust and sustainability turn out to be viable moderators affecting, and influencing the strength and direction of AI, KM and PGI relationships. In particular, higher levels of trust and more substantial sustainability commitments enhance the positive impact of AI and KM on green innovation outcomes.
Practical implications
Understanding the impact of AI, KM, trust and sustainability offers valuable insights for organizational leaders and policymakers seeking to promote proactive green innovation within the oil and gas industry. Thus, organizations can increase the efficiency of sustainable product development, process improvement and environmental management by using robust AI technologies and effective KM systems. Furthermore, fostering trust among stakeholders and embedding sustainability principles into organizational culture can amplify the effectiveness of AI and KM initiatives in driving green innovation outcomes.
Originality/value
This study extends the current knowledge by assessing the effect of AI and KM on proactive green innovation while accounting for trust and sustainability as moderators. Utilizing quantitative methods offers a nuanced understanding of the complex interactions between these variables, thereby advancing theoretical knowledge in the fields of innovation management, sustainability and organizational behavior. Additionally, the identification of specific mechanisms and contextual factors enriches practical insights for organizational practitioners striving for a practical understanding of the dynamics of the complexities of sustainable innovation in an AI-driven era.
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Hakan Coşanay, Hakan F. Oztop and Fatih Selimefendigil
The purpose of this study is to perform computational analysis on the steady flow and heat transfer due to a slot nanojet impingement onto a heated moving body. The object is…
Abstract
Purpose
The purpose of this study is to perform computational analysis on the steady flow and heat transfer due to a slot nanojet impingement onto a heated moving body. The object is moving at constant speed and nanoparticle is included in the heat transfer fluid. The unsteady flow effects and interactions of multiple impinging jets are also considered.
Design/methodology/approach
The finite volume method was used as the solver in the numerical simulation. The movement of the hot body in the channel is also considered. Influence of various pertinent parameters such as Reynolds number, jet to target surface spacing and solid nanoparticle volume fraction on the convective heat transfer characteristics are numerically studied in the transient regime.
Findings
It is found that the flow field and heat transfer becomes very complicated due to the interaction of multiple impinging jets with the movement of the hot body in the channel. Higher heat transfer rates are achieved with higher values of Reynolds number while the inclusion of nanoparticles resulted in a small impact on flow friction. The middle jet was found to play an important role in the heat transfer behavior while jet and moving body temperatures become equal after t = 80.
Originality/value
Even though some studies exist for the application of jet impingement heat transfer for a moving plate, the configuration with a solid moving hot body on a moving belt under the impacts of unsteady flow effects and interactions of multiple impinging jets have never been considered. The results of the present study will be helpful in the design and optimization of various systems related to convective drying of products, metal processing industry, thermal management in electronic cooling and many other systems.
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Simon Lee, Abdou Illia and Assion Lawson‐Body
This study aims to adopt illusion of control and lateral consumer relationship in order to investigate their effects on price fairness in online auction and group buying context…
Abstract
Purpose
This study aims to adopt illusion of control and lateral consumer relationship in order to investigate their effects on price fairness in online auction and group buying context. These two variables have been known to have strong influences in fairness perception on consumers' decision‐making processes and outcomes.
Design/methodology/approach
The authors draw their conceptual foundations from previous studies, supplement this from the electronic commerce literature, and test the model through laboratory experiments.
Findings
The study demonstrates that consumers' perception on illusion control in price determination and advantageous lateral consumer relationship significantly affect price fairness perception in both the online auction and group buying environments.
Research limitations/implications
The findings are expected to provide researchers with useful insights to conduct future studies on uncovering the nomological networks associated with price fairness perception.
Practical implications
The findings are expected to help managers develop better pricing strategies and design effective dynamic pricing mechanisms.
Originality/value
The paper provides the first integrated perspective on the human decision processes in the dynamic pricing environment in electronic markets.