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Wear behaviour characterization of ti6al4vb4c composites

- Ogunlana, Musibau O., Akinlabi, Esther Titilayo

  • Authors: Ogunlana, Musibau O. , Akinlabi, Esther Titilayo
  • Date: 2016
  • Subjects: Ball-on-disc , Linearly reciprocating , Sliding wear
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/214412 , uj:21278 , Citation: Ogunlana, M.O & Akinlabi, E.T. 2016. Wear behaviour characterization of ti6al4vb4c composites.
  • Description: Abstract: Dry sliding wear behaviour is fundamental mainly in typical components in manufacturing which has been found to correlate to both safety and cost effective. Thus, wear behaviours were carried out using ball-on-disc tribometer equipment called CETRUMT-2 which operates with linear reciprocating motion drive. Ball-on-disc test is regarded as one of the most common tests used to study and analyse the wear behaviour. Evaluating the wear volume and wear rate of respective samples, ball-on-disc tests were performed on the Universal Micro materials Tester (UMT-2), produced by Centre for Tribology, Inc. (CETR), USA. The wear tests were performed using a tungsten carbide ball of about 10 mm diameter with a constant stroke length of 2 mm together with application normal load of 25 N. Thus, frequency for the reciprocating spindle was maintained at 5 Hz together with speed of 5 mm/s which was also maintained throughout the test. In this paper, the ball-on-disc was used for the investigation of the effects of normal load and hardness of Ti6Al4V-B4C composites on wear behaviour under dry and sliding conditions...
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Wear and hardness properties of surface modification of copper alloy processed by friction stir process

- Sanusi, Kazeem O., Akinlabi, Esther Titilayo

Three-dimensional simulation of a single pass hot rolling of carbon steel : case of instabilities in steady state region

- Musonda, V., Akinlabi, Esther Titilayo

Thermodynamic optimization tools for power tracking in a multistage concentrated solar power Rankine plant

- Nwosu, P. N., Nurick, A., Akinlabi, Esther Titilayo

The role of transverse speed on deposition height and material efficiency in laser deposited titanium alloy

- Mahamood, Rasheedat M., Akinlabi, Esther Titilayo, Shukla, Mukul, Pityana, Sisa

  • Authors: Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo , Shukla, Mukul , Pityana, Sisa
  • Date: 2013
  • Subjects: Additive manufacturing , Laser metal deposition , Material efficiency , Titanium alloy
  • Type: Article
  • Identifier: uj:4895 , http://hdl.handle.net/10210/12609
  • Description: The most commonly used aerospace titanium alloy, Ti6Al4V, was deposited on Ti6Al4V plate of dimension 72 x 72 x5mm. The laser power of 3 kW, powder flow rate of 1.44 g/min and gas flow rate of 4 l/min were used throughout the deposition process. The transverse/ scanning speed was varied between 0.005 to 0.095 m/sec according to established result of the preliminary study that produces full dense and pore free deposits. The mass of the deposited powder was obtained by weight the substrate before deposition and reweighing after deposition. The substrate and the deposits were thoroughly cleaned using wire brush and acetone to remove unmelted powder particles from the surface of the substrate and the deposit. The height and width of the deposits were measured with Venier Caliper and the material efficiencies were determined using developed equations. The effect of the scanning speed on the material efficiency and deposit height were extensively studied and the results showed that for the set of processing parameter used in this study the optimum scanning speed is approximately 0.045 m/sec.
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The influence of scanning speed on laser metal deposition of Ti/TiC powders

- Sobiyi, K. K., Akinlabi, Esther Titilayo, Akinlabi, Stephen A.

  • Authors: Sobiyi, K. K. , Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
  • Date: 2017
  • Subjects: Titanium , Lasers , Metal deposition
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/241302 , uj:24840 , Citation: Sobiyi, K.K. 2017. The influence of scanning speed on laser metal deposition of Ti/TiC powders.
  • Description: Abstract: This paper describes the experimental work performed on laser metal deposition (LMD) of titanium carbide powders on pure titanium substrate. The understanding the effect of LMD processing parameters is vital in controlling the properties of the final product fabricated from the LMD process. The objective of the study is to characterize the influence of laser scanning speed of metal deposition of titanium and titanium carbide powders on pure titanium substrate. Microstructural characterization results showed that the substrate is characterized by two-phase morphology; alpha and beta phase. Deposit zone microstructures showed that the grains are of continuous columnar in nature. Heat affected zone region grain areas appear to decrease with increasing in scanning speed for different samples at different scanning speeds. The height of samples at different scanning was observed to decrease with increase in scanning speed. Microhardness results showed that the hardness of the deposits is greater than the hardness of the substrate. Wear resistance performance results showed that the coefficient of friction of substrate is greater than the coefficient of friction of the deposit samples. Wear volume loss of material of the substrate is higher than the deposits. The deposit contains titanium carbide and, as such, this powder has improved the wear resistance performance of the substrate.
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The influence of scanning speed and number of scans on the properties of laser formed steel

- Sanusi, Kazeem Oladele, Akinlabi, Stephen, Akinlabi, Esther Titilayo

The effects of rapid cooling on the improved surface properties of aluminium based coatings by direct laser deposition

- Fatoba, Olawale Samuel, Makhatha, Mamookho Elizabeth, Akinlabi, Esther Titilayo

Sustainable supply chain management in construction firms

- Ojo, Elizabeth, Mbohwa, Charles, Akinlabi, Esther Titilayo

  • Authors: Ojo, Elizabeth , Mbohwa, Charles , Akinlabi, Esther Titilayo
  • Date: 2013
  • Subjects: Sustainability development. , Construction industry -Nigeria - Lagos , Construction industry - Environmental aspects , Supply chain management
  • Type: Article
  • Identifier: uj:4873 , ISBN 978-0-9566060-6-8 , http://hdl.handle.net/10210/12549
  • Description: Environmental change is happening everywhere. Turbulent weather patterns - heat waves, rains, snowfalls, hurricanes and stormy rains are becoming extreme in every sense throughout the world. These climatic changes are today a concern of every individual and world leader alike. The burning of oil and other fossil fuels releases carbon dioxide, which rises, blankets the earth and traps heat causing severe changes in weather patterns. Not only do we have climate problems but we are also dealing with a resource depletion issue. The construction industry has a major impact on the environment because 50% of the material resources for construction are taken from nature. The huge consumption of resources by the construction industry has called for sustainable practices in construction. Sustainable supply chain provides economic, social and environmental requirements in material and service flows occurring between suppliers, manufacturers and customers. Sustainable development has taken the centre stage among different countries of the world. During the 1992 Earth Summit in Rio, the governments and other international organizations decided to take useful measures to protect the environment for long term social and economic development. This paper aims at investigating the compliance of the construction industry to environmental regulations. In this paper, the construction industry of Lagos state in Nigeria was used as a case study.
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Sustainable hydrogen generation substrates, catalysts and methods : an overview

- Adeniran, J. A., DeKoker, J. J., Akinlabi, Esther Titilayo, Jen, T. C.

  • Authors: Adeniran, J. A. , DeKoker, J. J. , Akinlabi, Esther Titilayo , Jen, T. C.
  • Date: 2017
  • Subjects: Hydrogen generation , Hydrolysis , Ball milling
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/231926 , uj:23640 , Citation: Adeniran, J.A. et al. 2017. Sustainable hydrogen generation substrates, catalysts and methods : an overview.
  • Description: Abstract: Because of the increasing demand for energy, various alternative sources of energy generation are being examined. Interest in hydrogen generation is on the rise due to its potential as a scalable green energy source, its transportability, and other positive factors. While various studies have been conducted on hydrogen generation, this review explores three major factors in hydrogen generation in relation to sustainability: substrates or hydrogen storage media, catalysts for speeding up the rate of hydrogen reaction, and methods employed. The media used to store the hydrogen, such as metal hydrides and complex hydrides, is examined in relationship to hydrogen yield, ease of hydrogen generation or treatment, cost and environmental friendliness. A list of popular catalysts - particularly precious/rare earth metals, strong acids and weak acids - is examined and compared in terms of hydrogen yield, environmental friendliness, and cost. The recent trend in hydrogen generation techniques and material treatment innovations such as hydrolysis, and ball milling of nanocomposites is examined. Innovations in hydrogen storage material selection and techniques will go a long way in lowering hydrogen generation cost, increasing hydrogen yield and ameliorating negative environmental impacts.
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Surface effect of laser power on microstructural evolution and hardness behaviour of titanium matrix composites

- Ogunlana, Musibau O., Akinlabi, Esther Titilayo

  • Authors: Ogunlana, Musibau O. , Akinlabi, Esther Titilayo
  • Date: 2016
  • Subjects: Boron carbide , Laser metal deposition , Titanium alloy
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/92390 , uj:20224 , Citation: Ogunlana, M.O., & Akinlabi, E.L. 2016. Surface effect of laser power on microstructural evolution and hardness behaviour of titanium matrix composites.
  • Description: Abstract: In this paper, Titanium alloy (Ti6Al4V) powder and boron carbide (B4C) powder metal matrix composites (MMCs) were embedded on titanium alloy (Ti6Al4V) substrate using laser metal deposition (LMD). The laser power was varied between 800 W and 2400 W at an interval of 200 W while all other processing parameters were kept constant. The maximum capacity of the laser system is 3.0 KW which provides beam size of 4 mm for the control characterization of the deposited samples. The microstructural properties of the deposited samples were profound with α and β (intermetallic phase of α+β) of titanium alloy and boron carbide particles. The optical microscope (OM) was employed to characterise the grain sizes and microstructures. The microhardness were characterized using the Vickers’ hardness indenter in which the microhardness of the composites revealed an increase in the samples as the laser power increases. The hardness were observed to be between 371Hv and 471Hv for the cladded samples when compared to the substrate with approximately 360Hv.
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Study on microstructure and mechanical properties of 304 stainless steel joints by TIG-MIG hybrid welding

- Ogundimu, Emmanuel O., Akinlabi, Esther Titilayo, Erinosho, Mutiu F.

  • Authors: Ogundimu, Emmanuel O. , Akinlabi, Esther Titilayo , Erinosho, Mutiu F.
  • Date: 2017
  • Subjects: 304 austenitic stainless steel , MIG welding , TIG welding
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/237818 , uj:24372 , Citation: Ogundimu, E.O., Akinlabi, E.T. & Erinosho, M.F. 2017. Study on microstructure and mechanical properties of 304 stainless steel joints by TIG-MIG hybrid welding.
  • Description: Abstract: Stainless steel is a family of Fe-based alloys having excellent resistance to corrosion, and as such has been used imperatively for kitchen utensils, transportation, building constructions and much more. This paper presents the work conducted on the material characterizations of a TIG-MIG hybrid welded joint of type 304 austenitic stainless steel. The welding processes were conducted in three phases. The phases of welding employed are MIG welding using a current of 170A, TIG welding using the current of 190A, and a hybrid TIG-MIG welding with currents of 190/170A respectively. The MIG, TIG, and hybrid TIG-MIG weldments were characterized with incomplete penetration, full penetration and excess penetration of weld. Intergranular austenite was created towards the transition zone and the HAZ. The thickness of the delta ferrite (δ-Fe) formed in the microstructures of the TIG weld is more than the thickness emerged in the microstructures of MIG weld and hybrid TIG-MIG welds. A TIG-MIG hybrid weld of specimen welded at the currents of 190/170A has the highest UTS value and percentage elongation of 397.72 MPa and 35.7 %. The TIG-MIG hybrid welding can be recommended for high-tech industrial applications such as nuclear, aircraft, food processing, and automobile industry.
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Study of friction during forging operation

- Erinosho, Mutiu F., Akinlabi, Esther Titilayo

  • Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo
  • Date: 2016
  • Subjects: Double cup extrusion , Friction factor , Lubrication
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://ujcontent.uj.ac.za8080/10210/375142 , http://hdl.handle.net/10210/92406 , uj:20226 , Citation: Erinosho, M.F. & Akinlabi, E.T. 2016. Study of friction during forging operation.
  • Description: Abstract: This paper presents a review on the effect of friction during forging operation; must especially the double cup extrusion process. The metal forming process, such as forging, is one of the manufacturing processes where metal is pressed or forced under great pressure into high strength parts. Before the process, lubricant is applied to the dies in operation to promote the flow of metal, to reduce friction and wear, and to aid in the release of the finished part. Interfacial friction between the forgings dies and the workpiece such as billet has a significant effect on the forging applications, forming quality, and deformation loads. The most commonly used lubricant is liquid based lubricant, such as water-based graphite, synthetic oils, liquid soap, shear butter etc. Under the high pressure condition and reductions of the lubricant film often breaks down the operation and caused poor metal flow and wears. High interface friction is a primary cause for adhesive pickup in cold forging.
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Scanning speed and powder flow rate influence on the properties of laser metal deposition of titanium alloy

- Mahamood, Rasheedat M., Akinlabi, Esther Titilayo

  • Authors: Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo
  • Date: 2017
  • Subjects: Additive manufacturing , Mechanical properties , Optical microscopy
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/238165 , uj:24416 , Citation: Mahamood, R.M. & Akinlabi, E.T. 2017. Scanning speed and powder flow rate influence on the properties of laser metal deposition of titanium alloy.
  • Description: Abstract: Ti4Al4V is an important aerospace alloy because of its excellent properties that include high strength to weight ratio and corrosion resistance. In spite of these impressive properties processing titanium is very challenging which contributes to the high cost of the material. laser metal deposition, an important additive manufacturing method is an excellent alternative manufacturing process for Ti6Al4V. The economy of this manufacturing process also depends on the right combination of processing parameters. The principal aim of this study is to know the optimum processing parameters that will result in deposit with sound metallurgical bonding with the substrate with proper mechanical property and better surface finish. This will help to reduce the need for expensive secondary finishing operations using this manufacturing process. This study investigates the influence of scanning speed and the powder flow rate on the resulting properties of the deposited samples. Microstructure, Microhardness and surface finish of Ti6Al4V samples that were produced using the laser metal deposition process over a range of scanning speeds, ranging from 0.02 to 0.12 m/s and powder flow rate of ranging from 0.72 to 6.48 g/min...
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Rhizophora mangle L. leaf biochemical characterization : natural-green totalcorrosion inhibition prospect on concrete steel-reinforcement in 3.5% NaCl

- Okeniyi, Joshua Olusegun, Akinlabi, Esther Titilayo, Ikotun, Jacob Olumuyiwa, Akinlabi, Stephen Akinwale, Okeniyi, Elizabeth Toyin, Ojewumi, Modupe Elizabeth

Revolutionary additive manufacturing : an overview

- Mahamood, R. M., Akinlabi, Esther Titilayo, Shukla, M., Pityana, S.

  • Authors: Mahamood, R. M. , Akinlabi, Esther Titilayo , Shukla, M. , Pityana, S.
  • Date: 2014
  • Subjects: Adaptive control , Additive manufacturing
  • Type: Article
  • Identifier: uj:4993 , http://hdl.handle.net/10210/13128
  • Description: Consumer demands are moving away from standardized to customized products, as such, the evolution of alternative manufacturing techniques has become imperative. Additive manufacturing (AM) is a process of building components layer by layer as against the traditional methods which are subtractive in nature. Though AM offers lots of advantages over traditional manufacturing techniques, its wide application is still however in the infancy phase. Despite all the benefits derived from AM technology, there are still a lot of unresolved issues with the technology that has hindered its performance thereby limiting its application to high tolerant jobs. This paper takes a look at some important AM technologies, some problems currently facing AM technology at large and proposes some solutions to these problems. A major known drawback in AM is poor dimensional accuracy and poor surface finish, only the layer height and melt pool temperature are controlled to solve this problem in the literature. The stair-stepping effect in adaptive manufacturing is rooted in a natural phenomenon of surface tension which is the cause of the poor surface finish and in combination with other factors is responsible for the poor dimensional accuracy. An adaptive controller is proposed for removing stair-stepping effect to improve the dimension accuracy, the surface finish and the mechanical properties of the components. Successful implementation of these proposed controllers will greatly improve the performance of AM technologies and also aid its wide application for end use products. Further research work is also suggested to improve the overall AM performance.
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Review on thermal, thermo-mechanical and thermal stress distribution during friction stir welding

- Ikumapayi, Omolayo M., Akinlabi, Esther Titilayo, Majumdar, Jyotsna D.

  • Authors: Ikumapayi, Omolayo M. , Akinlabi, Esther Titilayo , Majumdar, Jyotsna D.
  • Date: 2018
  • Subjects: Friction stir welding , Thermomechanical stress , Thermal stress
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/290706 , uj:31563 , Citation: Ikumapayi, O.M, Akinlabi, E.T. & Majumdar, J.D. 2018. Review on thermal, thermo-mechanical and thermal stress distribution during friction stir welding.
  • Description: Abstract: Thermal has significant effects on the metal structure during welding process; it plays vital roles in rearranging molecular structure of the metal being welded. It is of great importance to have the knowledge of thermal, temperature, thermo-mechanical and heat distribution on the workpiece in friction stir welding as this will help in designing process and the model parameters for welding application in the following welded joints, edge butt, lap, square butt, T lap, fillet, multiple lap etc. The physics of heat generation must be explored in order to understand the workability of friction stir welding (FSW). The FSW process begun with initial friction of mechanical that took place between the tool and the welded surface resulting in the generation of heat. Since the discovery of Friction Stir Welding (FSW) in 1991, many researchers have done tremendous investigations into the process and many experimental, theoretical, numerical, empirical, computational and analytical methods have been carried out in order to analyse and optimize FSW and to understand the complex mechanism in friction stir welding at the same time to deal with effects of various parameters relating to thermal profile during the process of FSW.
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Repair of cracks in metals : a review

- Marazani, Tawanda, Madyira, Daniel M., Akinlabi, Esther Titilayo

Renewable energy: deployment and the roles of energy storage

- Masebinu, S. O., Akinlabi, Esther Titilayo, Muzenda, E., Aboyade, A. O.

  • Authors: Masebinu, S. O. , Akinlabi, Esther Titilayo , Muzenda, E. , Aboyade, A. O.
  • Date: 2016
  • Subjects: Energy storage , Environment , Renewable energy , Sustainability
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/93707 , uj:20381 , Citation: Masebinu, S.O. et al. 2016. Renewable energy: deployment and the roles of energy storage.
  • Description: Abstract: Hydro energy still remains the highest RE contributor to electricity generation globally, nevertheless, trends in solar and wind energy has shown increasing investment in RE. Though a decline in investment was observed between 2012 and 2013, yet investment in RE exceeded that of non-RE in the excess of $80 billion dollar. In 2014, investment increased by 16%. As developed countries get saturated with RE technologies, developing countries are now the focus for investment. Wistfully, path dependency problem, lack of adequate infrastructure and policy framework have been highlighted as the major barrier to RE deployment in developing countries. Also, lack of harmonised government agency for RE implementation, incentives and educational gap are the institutional and social barriers. Energy Storage (ES) is being promoted as the “game changer” with capability of smoothening the variability associated with the two RE technologies, wind and solar, with the highest deployment rate. Recent developments are indicative of cost reduction for ES. This paper therefore presents a concise and holistic review of renewable energy (RE) technologies for electricity generation and assess the roles of ES in mitigating intermittency associated with their generation profile.
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Property evolution of thermo-mechanically treated reinforcement bar

- Musonda, V., Akinlabi, Esther Titilayo

  • Authors: Musonda, V. , Akinlabi, Esther Titilayo
  • Date: 2018
  • Subjects: Property evolution , Microstructure , Reinforcement bars
  • Language: English
  • Type: Conference proceeding
  • Identifier: http://hdl.handle.net/10210/291125 , uj:31608 , Citation: Musonda, V. & Akinlabi, E.T. 2018. Property evolution of thermo-mechanically treated reinforcement bar.
  • Description: Abstract: Property evolution of microstructure of reinforcement bar (rebar) depends on how well the steel is treated during and after the Thermomechanical Treatment (TMT) box. Rebars are hot rolled - from low carbon steel through Tempcore technology. In order to achieve optimal properties, typical evolving mechanical properties of the rebar such as ultimate tensile strength (UTS), yield stress (YS) and the percentage elongation (%El) were conducted. This is necessary to control the tempering and cooling process. In this study, a simulation of the cooling rebar was investigated using finite element modelling (FEM). The material used for the model and production of the rebar was equivalent to AISI 1016 carbon steel and was produced from scrap supplemented with Direct Reduced Iron (DRI). The raw materials were melted in an Electric Arc Furnace (EAF) prior to hot rolling through a billet caster. The rod mill tensile test report showed that UTS and YS values ranged between 482 MPa for the YS and 650 MPa for UTS on an average. The average percentage elongation was found to be 23 % well above the 14 % threshold according to the standard. The pearlite-ferrite microstructure and the martensite developed is in agreement with the standard microstructure found in the literature.
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