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Esther T. Akinlabi

Bio: Esther T. Akinlabi is an academic researcher from Covenant University. The author has contributed to research in topics: Ultimate tensile strength & Aluminium alloy. The author has an hindex of 5, co-authored 26 publications receiving 57 citations.

Papers
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Journal ArticleDOI
12 Apr 2019
TL;DR: In this paper, friction stir processing was performed on AA7075-T651 aluminium metal composite (AMC) reinforced with α-β grade Titanium alloy powder (Ti−6Al−2Sn−2Zr−2Mo−2Cr−0.25Si) which is an excellent reinforcement material in airframe and jet engine applications for corrosion resistance and exceptional strength-to-weight ratio.
Abstract: Aluminium alloy AA7075-T651 is one of the newest and promising commercials rolled sheet metal for structural applications in defensive areas like military, space and air vehicle, aerospace because of its excellent and unbeatable combination of high strength-to-weight ratio and good corrosion resistance, high fatigue strength. In this study friction stir processing (FSP) was performed on AA7075-T651 aluminium metal composite (AMC) reinforced with α-β grade Titanium alloy powder (Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si) which is an excellent reinforcement material in airframe and jet engine applications for corrosion resistance and exceptional strength-to-weight ratio. The processing parameters used were the rotational speed of 1500 rpm, processing speed of 20 mm min−1, and tilt angle of 3°. Two passes were carried out on the FSP parameters with 100% inter-pass overlap i.e. plunge depth of 0.3 mm was used which was distributed thus, 0.2 mm plunge depth on first pass and 0.1 mm plunge depth second pass. Mechanical characterization was carried out to study the influence of α-β grade Titanium alloy powder (Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si), in this tensile strength was studied using Xforce P type of Zwick/Roell Z250 tensile testing machine and surface roughness analysis was conducted on Mitutoyo surf test SJ-210 surface roughness tester. Corrosion behaviour of the processed AMC was studied using potentiodynamic polarization technique in 3.5% NaCl solution at an ambient temperature of 25°. It was established that α-β grade Titanium alloy powder as reinforcement inhibitor produced the highest percentage of inhibition performance efficiency (IPE) of 98.26% while the processed base metal (PBM) gave IPE of 63.99% with reference to the unprocessed base metal (UBM). There was an extraordinary improvement in corrosion rate with a reduction from 5.0718 mm/year to 0.087 675 mm/year when α-β grade Titanium alloy powder was used as inhibitor. AA7075-T651/Ti–6Al–2Sn–2Zr–2Mo–2Cr–0.25Si AMC has highest ultimate tensile strength (UTS) of 624 MPa which has a close value of 620.903 MPa to that of AA7075-T651 without reinforcement but the UTS for UBM was far away from them.

23 citations

Journal ArticleDOI
TL;DR: In this paper, the impact of tool rotational speed on temperature profile, mechanical behaviour and microstructure of friction stir welding of dissimilar aluminium alloy 6101-T6 and 7075-T651 was studied.
Abstract: Temperature variations during friction stir welding result from the heat generated by the frictional action of a rotating tool on the workpiece. This temperature distribution affects the mechanical behaviour and ultimately the quality of welds produced. The study of the correlations between process parameter, temperature, mechanical properties and microstructure has become imperative in order to promote welds devoid of defects and possessing sound mechanical properties and to establish a temperature feedback control for effective components designs for industrial applications. This work studied the impact of tool rotational speed on temperature profile, mechanical behaviour and microstructure of friction stir welding of dissimilar aluminium alloy 6101-T6 and 7075-T651. Processing parameters of three different rotational speeds with values 1250 rpm, 1550 rpm and 1850 rpm and a constant travel speed of 50 mm/min were employed. The temperature profile was measured with one end of thermocouple wires embedded in the plates and the other end connected to a data capturing software device. The temperature profile indicates that the temperature rises with time and is higher at the retreating sides than at the advancing side of the weld. The tensile test results show that the ultimate tensile strength decreases as the temperature increases. Microstructural observations of weld zone revealed non-uniformity in material flow. However, more material penetration into each other occurred more at 1550 rpm.

18 citations

BookDOI
01 Jan 2020
TL;DR: Barkalov et al. as mentioned in this paper proposed a model for controlling control systems based on the theory of control systems and applied it in the field of applied mathematics at the University of Zielona Góra, Poland.
Abstract: ,!7ID0D0-dhabef! Order Quantity A. Barkalov, University of Zielona Gora, Poland, Chair of Applied Mathematics and Theory of Control Systems, Vasyl Stus‘ Donetsk National University (in Vinnytsia), Zielona Gora, Ukraine; L. Titarenko, University of Zielona Gora, Kharkov National University of Radio Electronics, Zielona Gora, Poland; K. Mielcarek, Institute of Metrology, Electronics and Computer Science, Zielona Góra, Poland; S. Chmielewski, State Higher Vocational School (PWSZ), Głogów, Poland

16 citations

Book ChapterDOI
21 Dec 2017
TL;DR: Additive manufacturing (AM) is a breaking edge fabrication technique with the possibility of changing the perception of design and manufacturing as a whole as mentioned in this paper, which is well suitable for the building and repairing applications in the aerospace industry which usually requires high level of accuracy and customization of parts which usually employ materials known to pose difficulties in fabrication such as titanium alloys.
Abstract: Modern industrial applications require materials with special surface properties such as high hardness, wear and corrosion resistance. The performance of material surface under wear and corrosion environments cannot be fulfilled by the conventional surface modifications and coatings. Therefore, different industrial sectors need an alternative technique for enhanced surface properties. The purpose of this is to change or enhance inherent properties of the materials to create new products or improve on existing ones. The most effective and economical engineering solution to prevent or minimize such surface region of a component is done by fiber lasers. Additive manufacturing (AM) is a breaking edge fabrication technique with the possibility of changing the perception of design and manufacturing as a whole. It is well suitable for the building and repairing applications in the aerospace industry which usually requires high level of accuracy and customization of parts which usually employ materials known to pose difficulties in fabrication such as titanium alloys. The current development focus of AM is to produce complex shaped functional metallic components, including metals, alloys and metal matrix composites (MMCs), to meet demanding requirements from aerospace, defense, and automotive industries.

10 citations

Journal ArticleDOI
01 Nov 2020-Heliyon
TL;DR: The results shown have justified the relevant effect of agro-waste materials in composite development and adopted the Stir casting method based on availability and cost-effectiveness as the cheapest method amongst others.

9 citations


Cited by
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Journal ArticleDOI
TL;DR: As the forging counterpart of fusion-based additive processes, additive friction stir deposition offers a solid-state deformation processing route to metal additive manufacturing, in which every vo... as discussed by the authors.
Abstract: As the forging counterpart of fusion-based additive processes, additive friction stir deposition offers a solid-state deformation processing route to metal additive manufacturing, in which every vo...

63 citations

Journal ArticleDOI
TL;DR: In this paper, the authors view advanced welding manufacturing as a three-step approach: (1) pre-design that selects process and joint design based on available processes (properties, capabilities, and costs); (2) design that uses models to predict the result from a given set of welding parameters and minimizes a cost function for optimizing the welding parameters; and (3) real-time sensing and control that overcome the deviations of welding conditions from their nominal ones used in optimizing the weld parameters.
Abstract: Welding is a major manufacturing process that joins two or more pieces of materials together through heating/mixing them followed by cooling/solidification. The goal of welding manufacturing is to join materials together to meet service requirements at lowest costs. Advanced welding manufacturing is to use scientific methods to realize this goal. This paper views advanced welding manufacturing as a three step approach: (1) pre-design that selects process and joint design based on available processes (properties, capabilities, and costs); (2) design that uses models to predict the result from a given set of welding parameters and minimizes a cost function for optimizing the welding parameters; and (3) real-time sensing and control that overcome the deviations of welding conditions from their nominal ones used in optimizing the welding parameters by adjusting the welding parameters based on such real-time sensing and feedback control. The paper analyzes how these three steps depend on process properties/capabilities, process innovations, predictive models, numerical models for fluid dynamics, numerical models for structures, real-time sensing, and dynamic control. The paper also identifies the challenges in obtaining ideal solutions and reviews/analyzes the existing efforts toward better solutions. Special attention and analysis have been given to (1) gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) as benchmark processes for penetration and materials filling; (2) keyhole plasma arc welding (PAW), keyhole-tungsten inert gas (K-TIG), and keyhole laser welding as improved/capable penetrative processes; (3) friction stir welding (FSW) as a special penetrative low heat input process; (4) alternating current (AC) GMAW and double-electrode GMAW as improved materials filling processes; (5) efforts in numerical modeling for fluid dynamics; (6) efforts in numerical modeling for structures; (7) challenges and efforts in seam tracking and weld pool monitoring; (8) challenges and efforts in monitoring of keyhole laser welding and FSW; and (9) efforts in advanced sensing, data fusion/sensor fusion, and process control using machine learning/deep learning, model predictive control (MPC), and adaptive control.

45 citations

Journal ArticleDOI
TL;DR: Directed energy deposition (DED) has matured into an essential additive manufacturing branch as discussed by the authors and has been broadly implemented in the design and fabrication of novel materials, including metals, ceramics, and composites.
Abstract: Directed energy deposition (DED) has matured into an essential additive manufacturing (AM) branch. DED has been broadly implemented in the design and fabrication of novel materials. These include metals, ceramics, and composites. Successful DED operation requires a good understanding of many critical phenomena, including laser-material interactions, fundamentals of casting and solidification of alloys, welding metallurgy and joining interfaces, along with microstructure-mechanical properties relations. Also critical are powder flowability, heat transfer, and various machine-related parameters. Several review articles have been published in recent years on metal AM via powder bed fusion (PBF) and DED, focusing on either a specific material system, mapping the recent technologies for AM, or issues related to the deposition process or material properties. Yet, no recent review is dedicated to a comprehensive presentation of material systems, design, fabrication, challenges, and the relationship between microstructures and mechanical properties of various DED'ed material families. Since the DED-based approach is becoming popular to manufacture bimetallic and multi-material structures, repair high-value structures, and alloy design, this comprehensive review focuses on materials design via DED, including a survey of a variety of monolithic and multi-material compositions. Finally, the critical challenges and opportunities in this area are highlighted.

38 citations

Journal ArticleDOI
TL;DR: Friction stir alloying is primarily employed for the fabrication of surface composite to improve surface properties like hardness, wear resistance, and corrosion resistance without significantly affecting the quality of the composite as mentioned in this paper.
Abstract: Friction stir alloying is primarily employed for the fabrication of surface composite to improve surface properties like hardness, wear resistance, and corrosion resistance without significantly af...

32 citations

Proceedings ArticleDOI
01 Feb 2018
TL;DR: In this article, the effect of hybrid coatings of Al-Cu-Fe on a grade five titanium alloy (Ti6Al4V) using laser metal deposition (LMD) process at different laser power and scanning speeds was analyzed using Optical microscopy, Scanning electron microscopy (SEM), indentation testing, X-Ray Diffraction (XRD), corrosion and wear testing.
Abstract: Laser Additive Manufacturing is relatively new in the manufacturing industry. This paper focuses on the effect of hybrid coatings of Al-Cu-Fe on a grade five titanium alloy (Ti6Al4V) using laser metal deposition (LMD) process at different laser power and scanning speeds. Icosahedral Al-Cu-Fe as quasicrystals are a relatively new class of materials which exhibit unusual atomic structure and useful physical and chemical properties. Ti6Al4V/Al-Cu-Fe composite were analysed using Optical microscopy, Scanning electron microscopy (SEM) with energy dispersive microscopy (EDS), indentation testing, X-Ray Diffraction (XRD), corrosion and wear testing. deposit width and height, heat affected zone (HAZ) height), dilution rate, aspect ratio and powder efficiency of each sample remarkably increased with increasing laser power due to the laser-material interaction. It was observed that there are higher number of aluminium and titanium presented in the formation of the composite. The indentation testing reveals that for both scanning speed of 0.8m/min and 1m/min, the mean hardness value decreases with increasing laser power. It was found that due to dilution effect, a part of Ti entered into molten pool from the substrate. The results indicate that Ti, Al 3 Ti, Ti 3 Al, CuTi 2 can be produced through the in situ metallurgical reactions during the LMD process.

30 citations