Advanced coating: laser metal deposition of aluminium powder on titanium substrate
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2016
- Subjects: Heat affected zone , Laser metal deposition , Powder metallurgy
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93266 , uj:20325 , Citation: Akinlabi, E.T. & Akinlabi, S.A. 2016. Advanced coating: laser metal deposition of aluminium powder on titanium substrate.
- Description: Abstract: Laser Metal Deposition (LMD) is an additive manufacturing technique, which can be used to produce solid components from a Computer Aided Design (CAD) model. The LMD process makes use of feeding powder, which is supported by the shielding gas, into the melt pool that is produced by sharply focused collimated laser beam on the substrate. This study employs aluminium powder in its molten state on titanium substrate through the LMD process. The aluminium powder was deposited at varying laser scanning speeds while the laser power and gas flow rate were kept constant. The presence of alpha phase grains were observed in the microstructures of samples at a lower scanning speed and the beta phase grains at a higher laser scanning speed. It was found that the geometrical properties of the deposits, that is; the width, height and the Heat Affected Zone (HAZ) of each sample decreased as the scan speed increases resulting from the laser-material interaction. The microhardness and the corrosion rates of each sample increased as the laser scanning speed increases.
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2016
- Subjects: Heat affected zone , Laser metal deposition , Powder metallurgy
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93266 , uj:20325 , Citation: Akinlabi, E.T. & Akinlabi, S.A. 2016. Advanced coating: laser metal deposition of aluminium powder on titanium substrate.
- Description: Abstract: Laser Metal Deposition (LMD) is an additive manufacturing technique, which can be used to produce solid components from a Computer Aided Design (CAD) model. The LMD process makes use of feeding powder, which is supported by the shielding gas, into the melt pool that is produced by sharply focused collimated laser beam on the substrate. This study employs aluminium powder in its molten state on titanium substrate through the LMD process. The aluminium powder was deposited at varying laser scanning speeds while the laser power and gas flow rate were kept constant. The presence of alpha phase grains were observed in the microstructures of samples at a lower scanning speed and the beta phase grains at a higher laser scanning speed. It was found that the geometrical properties of the deposits, that is; the width, height and the Heat Affected Zone (HAZ) of each sample decreased as the scan speed increases resulting from the laser-material interaction. The microhardness and the corrosion rates of each sample increased as the laser scanning speed increases.
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Characterising the effect of springback on mechanically formed steel plates
- Akinlabi, Esther Titilayo, Matlou, Kagisho, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Matlou, Kagisho , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Mechanical forming , Springback
- Type: Article
- Identifier: uj:4724 , ISSN 2078-0958 , http://hdl.handle.net/10210/11549
- Description: In the bending operation, springback causes geometrical inaccuracies of bent parts. To curb springback, various factors such as bending parameters and material properties need to be considered. This paper reports the effects of springback on mechanically formed steel plates. Experimental work using circular bending was conducted to analyse the effect of springback on the formed steel sheets. The sheets were bent using a punch and die having a radius of curvature of 120 mm. In addition, the formed samples were characterized through microstructure, microhardness and tensile results. The results revealed an error due to springback of 4.24%. Furthermore, the Vickers microhardness of the formed samples compared to the parent materials shows an increase of 6% while the Ultimate Tensile Strength also increased by 7%. The effects of strain hardening resulting from the bending process led to the increased hardness and strength of the material. The formed samples had elongated grains when compared to the equiaxed grains of the parent material. The increase in the grains can be attributed to the stretching of the material during the bending process.
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- Authors: Akinlabi, Esther Titilayo , Matlou, Kagisho , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Mechanical forming , Springback
- Type: Article
- Identifier: uj:4724 , ISSN 2078-0958 , http://hdl.handle.net/10210/11549
- Description: In the bending operation, springback causes geometrical inaccuracies of bent parts. To curb springback, various factors such as bending parameters and material properties need to be considered. This paper reports the effects of springback on mechanically formed steel plates. Experimental work using circular bending was conducted to analyse the effect of springback on the formed steel sheets. The sheets were bent using a punch and die having a radius of curvature of 120 mm. In addition, the formed samples were characterized through microstructure, microhardness and tensile results. The results revealed an error due to springback of 4.24%. Furthermore, the Vickers microhardness of the formed samples compared to the parent materials shows an increase of 6% while the Ultimate Tensile Strength also increased by 7%. The effects of strain hardening resulting from the bending process led to the increased hardness and strength of the material. The formed samples had elongated grains when compared to the equiaxed grains of the parent material. The increase in the grains can be attributed to the stretching of the material during the bending process.
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Characterising the effects of heat treatment on 3CR12 and AISI 316 stainless steels
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2014
- Subjects: Stainless steel - Heat treatment
- Type: Article
- Identifier: uj:4736 , http://hdl.handle.net/10210/11722
- Description: This paper reports on the effects of heat treatment on 3CR12 and AISI 316 stainless steel grades. Heat treatment was conducted on the steel grades and cooled using two different media; air and water in order to study the effect of each medium on the evolving properties of the samples. The heat treated samples were characterized through the evolving microstructure and hardness. It was found that there was a significant grain size reduction in both the heat treated stainless steel specimens compared to the parent materials. The finer grain sizes were achieved as a result of impediment to growth of one phase by the other. The Vickers microhardness values of the heat treated samples were higher compared to the parent materials due to the fact that each of the steel grades had a proportion of martensitic structures in their microstructures thereby improving the integrity of the material.
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2014
- Subjects: Stainless steel - Heat treatment
- Type: Article
- Identifier: uj:4736 , http://hdl.handle.net/10210/11722
- Description: This paper reports on the effects of heat treatment on 3CR12 and AISI 316 stainless steel grades. Heat treatment was conducted on the steel grades and cooled using two different media; air and water in order to study the effect of each medium on the evolving properties of the samples. The heat treated samples were characterized through the evolving microstructure and hardness. It was found that there was a significant grain size reduction in both the heat treated stainless steel specimens compared to the parent materials. The finer grain sizes were achieved as a result of impediment to growth of one phase by the other. The Vickers microhardness values of the heat treated samples were higher compared to the parent materials due to the fact that each of the steel grades had a proportion of martensitic structures in their microstructures thereby improving the integrity of the material.
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Characterising the effects of sand blasting on formed steel samples
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A., Ogunmuyiwa, Enoch
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A. , Ogunmuyiwa, Enoch
- Date: 2013
- Subjects: Metal forming , Sand blasting , Ultimate tensile strength
- Type: Article
- Identifier: uj:4880 , http://hdl.handle.net/10210/12593
- Description: The present research study focuses on the investigation of the influence of sand blasting on formed mild steel samples. The investigation involved the examinations on the parent material and a sand blasted material. The results were compared to the mechanically formed materials (sand and non-sand blasted) as well as a laser formed material (sand and non-sand blasted). Each material was characterized for the grain sizes and hardness. The percentage change in the grain sizes was quantified and correlation to the microhardness values was established. The Ultimate Tensile Strength (UTS) of the materials was also quantified using the obtained hardness values. The investigations revealed that the sand blasting causes an increase in the Vickers microhardness values of all the materials which also led to an increase in the UTS. After the forming operation, the microstructure revealed elongated grains as compared to almost equiaxed obtained from the parent non-sand blasted materials.
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A. , Ogunmuyiwa, Enoch
- Date: 2013
- Subjects: Metal forming , Sand blasting , Ultimate tensile strength
- Type: Article
- Identifier: uj:4880 , http://hdl.handle.net/10210/12593
- Description: The present research study focuses on the investigation of the influence of sand blasting on formed mild steel samples. The investigation involved the examinations on the parent material and a sand blasted material. The results were compared to the mechanically formed materials (sand and non-sand blasted) as well as a laser formed material (sand and non-sand blasted). Each material was characterized for the grain sizes and hardness. The percentage change in the grain sizes was quantified and correlation to the microhardness values was established. The Ultimate Tensile Strength (UTS) of the materials was also quantified using the obtained hardness values. The investigations revealed that the sand blasting causes an increase in the Vickers microhardness values of all the materials which also led to an increase in the UTS. After the forming operation, the microstructure revealed elongated grains as compared to almost equiaxed obtained from the parent non-sand blasted materials.
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Characterization of functionally graded commercially pure titanium (CPTI) and titanium carbide (TiC) powders
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2015-07-01
- Subjects: Functional graded materials , Laser metal deposition , Titanium , Titanium carbide
- Type: Article
- Identifier: uj:5136 , ISBN 9789881404701 , http://hdl.handle.net/10210/14102
- Description: Functionally Graded Materials (FGM) are advanced materials fabricated using additive manufacturing techniques. It belongs to a class of advanced material characterization in which the properties of the material composition is varied. The resulting property of the composite is always different from the properties of the individual material employed in the formation of the composite. They are known to also exhibit good mechanical and chemical properties and as such, are used for different industrial applications. One of the techniques employed in the fabrication of FGMs is called Laser Metal Deposition (LMD) technique. It uses laser beam to melt powder material on a substrate forming a melt pool that solidifies upon cooling. This paper reports on the material characterization of functionally graded Titanium and Titanium Carbide (TiC) powders deposited on Titanium substrate by laser metal deposition approach. The formed deposits were fabricated by varying the processing parameters such as laser power, scanning speed and the powder flow rate. From the result obtained, the microstructures showed that the laser power has much influence on the grain growth of the material. In addition, with the SEM analysis of the microstructure since the percentages of the titanium and titanium carbide were varied, it was observed that the sharp boundaries of the Titanium Carbide were reduced greatly and this resulting effect can be attributed to the thermal effect of the laser. The microstructures further revealed that as the percentage of TiC decreases, it becomes more difficult to see the TiC as a different material in the composite, emphasizing this as one of the best characteristics of functionally graded materials, which is the elimination of sharp interfaces and layers. Furthermore, it was observed that the laser power has great influence on the evolving hardness of the material compared to the TiC content.
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2015-07-01
- Subjects: Functional graded materials , Laser metal deposition , Titanium , Titanium carbide
- Type: Article
- Identifier: uj:5136 , ISBN 9789881404701 , http://hdl.handle.net/10210/14102
- Description: Functionally Graded Materials (FGM) are advanced materials fabricated using additive manufacturing techniques. It belongs to a class of advanced material characterization in which the properties of the material composition is varied. The resulting property of the composite is always different from the properties of the individual material employed in the formation of the composite. They are known to also exhibit good mechanical and chemical properties and as such, are used for different industrial applications. One of the techniques employed in the fabrication of FGMs is called Laser Metal Deposition (LMD) technique. It uses laser beam to melt powder material on a substrate forming a melt pool that solidifies upon cooling. This paper reports on the material characterization of functionally graded Titanium and Titanium Carbide (TiC) powders deposited on Titanium substrate by laser metal deposition approach. The formed deposits were fabricated by varying the processing parameters such as laser power, scanning speed and the powder flow rate. From the result obtained, the microstructures showed that the laser power has much influence on the grain growth of the material. In addition, with the SEM analysis of the microstructure since the percentages of the titanium and titanium carbide were varied, it was observed that the sharp boundaries of the Titanium Carbide were reduced greatly and this resulting effect can be attributed to the thermal effect of the laser. The microstructures further revealed that as the percentage of TiC decreases, it becomes more difficult to see the TiC as a different material in the composite, emphasizing this as one of the best characteristics of functionally graded materials, which is the elimination of sharp interfaces and layers. Furthermore, it was observed that the laser power has great influence on the evolving hardness of the material compared to the TiC content.
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Comparison of quality infrastructure of the Republic of South Africa and Sweden
- Ntlhane, Makibane Daniel, Akinlabi, Stephen A., Mbohwa, Charles
- Authors: Ntlhane, Makibane Daniel , Akinlabi, Stephen A. , Mbohwa, Charles
- Date: 2016
- Subjects: Infrastructure (Economics) - Management , Infrastructure (Economics) - South Africa , Infrastructure (Economics) - Sweden , Engineering economy , Quality infrastructure
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217201 , uj:21610 , Citation: Ntlhane, M.D., Akinlabi, S.A. & Mbohwa, C. 2016. Comparison of quality infrastructure of the Republic of South Africa and Sweden.
- Description: Abstract: The study focuses on Comparative Study of Quality Infrastructure (QI) between Republic of South Africa (RSA) and Sweden. QI is important for the reason that it provides technical support to companies in order to improve their production processes and ensuring compliance to regulations or international requirements. QI in this study refers to six foremost institutions, which are accreditation body, inspection body, testing laboratory, certification body, metrology institution and standardization body. The methodology employed was by data collections through questionnaires and interviews. The result of the study found that the QI of both South Africa and Sweden is the same based on the types of institutions. It was also observed that the employees of both countries are offered long services of minimum of seven years. A significant difference of 22.6% was reported between the two countries with respect to agreement that law mandates compliance with standard. It was further observed that the QI of both South Africa and Sweden plays a role in reducing non-compliance and adding value to the economies of these countries.
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- Authors: Ntlhane, Makibane Daniel , Akinlabi, Stephen A. , Mbohwa, Charles
- Date: 2016
- Subjects: Infrastructure (Economics) - Management , Infrastructure (Economics) - South Africa , Infrastructure (Economics) - Sweden , Engineering economy , Quality infrastructure
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217201 , uj:21610 , Citation: Ntlhane, M.D., Akinlabi, S.A. & Mbohwa, C. 2016. Comparison of quality infrastructure of the Republic of South Africa and Sweden.
- Description: Abstract: The study focuses on Comparative Study of Quality Infrastructure (QI) between Republic of South Africa (RSA) and Sweden. QI is important for the reason that it provides technical support to companies in order to improve their production processes and ensuring compliance to regulations or international requirements. QI in this study refers to six foremost institutions, which are accreditation body, inspection body, testing laboratory, certification body, metrology institution and standardization body. The methodology employed was by data collections through questionnaires and interviews. The result of the study found that the QI of both South Africa and Sweden is the same based on the types of institutions. It was also observed that the employees of both countries are offered long services of minimum of seven years. A significant difference of 22.6% was reported between the two countries with respect to agreement that law mandates compliance with standard. It was further observed that the QI of both South Africa and Sweden plays a role in reducing non-compliance and adding value to the economies of these countries.
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Data showing the effects of disc milling time on the composition and morphological transformation of (aþb) titanium alloy (Tie6Ale2Sne2Moe2Cre2Zr-0.25Si) grade
- Ogbonna, Okwudili Simeon, Akinlabi, Stephen A., Madushele, Nkosinathi
- Authors: Ogbonna, Okwudili Simeon , Akinlabi, Stephen A. , Madushele, Nkosinathi
- Date: 2019
- Subjects: Titanium alloy , Milling time , SEM
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/402429 , uj:33676 , Citation: Ogbonna, O.S., Akinlabi, S.A. & Madushele, N. 2019. Data showing the effects of disc milling time on the composition and morphological transformation of (aþb) titanium alloy (Tie6Ale2Sne2Moe2Cre2Zr-0.25Si) grade. , DOI: https://doi.org/10.1016/j.dib.2019.104174
- Description: Abstract: In powder metallurgy, dry mechanical milling process is an effective technique employed in the reduction of solid materials into the desired size in the fabrication of materials or components from metal powders for various applications. However, the milling operation introduces changes in the size and shape as well as the elemental or chemical composition of the milled substance. These changes introduced after milling requires critical analyses as the performance and efficiency of fabricated components depend so much on the size, shape and chemical composition of the powders. In this data, the effects of vibratory disc milling on the morphological transformation and elemental composition of titanium alloy powder were observed and analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The as received titanium alloy powder was subjected to dry mechanical milling machine rated 380V/50Hz at 940 rpm. Milling time of 2, 4, 6, 8 and 10 mins were adopted in this data collection. SEM and EDS analyses revealed that milling transformed the spherical shaped powders into plate-like shapes. This deformation in the shape of the powder increased with increase in milling time. Also,..
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- Authors: Ogbonna, Okwudili Simeon , Akinlabi, Stephen A. , Madushele, Nkosinathi
- Date: 2019
- Subjects: Titanium alloy , Milling time , SEM
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/402429 , uj:33676 , Citation: Ogbonna, O.S., Akinlabi, S.A. & Madushele, N. 2019. Data showing the effects of disc milling time on the composition and morphological transformation of (aþb) titanium alloy (Tie6Ale2Sne2Moe2Cre2Zr-0.25Si) grade. , DOI: https://doi.org/10.1016/j.dib.2019.104174
- Description: Abstract: In powder metallurgy, dry mechanical milling process is an effective technique employed in the reduction of solid materials into the desired size in the fabrication of materials or components from metal powders for various applications. However, the milling operation introduces changes in the size and shape as well as the elemental or chemical composition of the milled substance. These changes introduced after milling requires critical analyses as the performance and efficiency of fabricated components depend so much on the size, shape and chemical composition of the powders. In this data, the effects of vibratory disc milling on the morphological transformation and elemental composition of titanium alloy powder were observed and analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The as received titanium alloy powder was subjected to dry mechanical milling machine rated 380V/50Hz at 940 rpm. Milling time of 2, 4, 6, 8 and 10 mins were adopted in this data collection. SEM and EDS analyses revealed that milling transformed the spherical shaped powders into plate-like shapes. This deformation in the shape of the powder increased with increase in milling time. Also,..
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Design of a support system for a re-configured milling machine to achieve friction stir welds
- Akinlabi, Esther Titilayo, Levy, Adrian C. S., Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Levy, Adrian C. S. , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Friction Stir Welding , Friction stir welds
- Type: Article
- Identifier: uj:4830 , ISSN 2078-0966 , http://hdl.handle.net/10210/12423
- Description: The detailed design of a clamping and support system for a reconfigured milling machine to produce friction stir welds is reported in this paper. Two different concepts were considered and subjected to performance evaluation. The selected design concept is expected to effectively clamp and support the workpiece during the process of friction stir welding to achieve a good integrity.
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- Authors: Akinlabi, Esther Titilayo , Levy, Adrian C. S. , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Friction Stir Welding , Friction stir welds
- Type: Article
- Identifier: uj:4830 , ISSN 2078-0966 , http://hdl.handle.net/10210/12423
- Description: The detailed design of a clamping and support system for a reconfigured milling machine to produce friction stir welds is reported in this paper. Two different concepts were considered and subjected to performance evaluation. The selected design concept is expected to effectively clamp and support the workpiece during the process of friction stir welding to achieve a good integrity.
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Design of an innovative accelerant detector
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A., Isvarial, Milan
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A. , Isvarial, Milan
- Date: 2012
- Subjects: Accelerant detectors
- Type: Article
- Identifier: uj:5338 , ISSN 2010-3778 , http://hdl.handle.net/10210/8898
- Description: Today, canines are still used effectively in acceleration detection situation. However, this method is becoming impractical in modern age and a new automated replacement to the canine is required. This paper reports the design of an innovative accelerant detector. Designing an accelerant detector is a long process as is any design process; therefore, a solution to the need for a mobile, effective accelerant detector is hereby presented. The device is simple and efficient to ensure that any accelerant detection can be conducted quickly and easily. The design utilizes Ultra Violet (UV) light to detect the accelerant. When the UV light shines on an accelerant, the hydrocarbons in the accelerant emit florescence. The advantages of using the UV light to detect accelerant are also outlined in this paper. The mobility of the device is achieved by using a Direct Current (DC) motor to run tank tracks. Tank tracks were chosen as to ensure that the device will be mobile in the rough terrain of a fire site. The materials selected for the various parts are also presented. A Solid Works Simulation was also conducted on the stresses in the shafts and the results are presented. This design is an innovative solution which offers a user friendly interface. The design is also environmentally friendly, ecologically sound and safe to use.
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A. , Isvarial, Milan
- Date: 2012
- Subjects: Accelerant detectors
- Type: Article
- Identifier: uj:5338 , ISSN 2010-3778 , http://hdl.handle.net/10210/8898
- Description: Today, canines are still used effectively in acceleration detection situation. However, this method is becoming impractical in modern age and a new automated replacement to the canine is required. This paper reports the design of an innovative accelerant detector. Designing an accelerant detector is a long process as is any design process; therefore, a solution to the need for a mobile, effective accelerant detector is hereby presented. The device is simple and efficient to ensure that any accelerant detection can be conducted quickly and easily. The design utilizes Ultra Violet (UV) light to detect the accelerant. When the UV light shines on an accelerant, the hydrocarbons in the accelerant emit florescence. The advantages of using the UV light to detect accelerant are also outlined in this paper. The mobility of the device is achieved by using a Direct Current (DC) motor to run tank tracks. Tank tracks were chosen as to ensure that the device will be mobile in the rough terrain of a fire site. The materials selected for the various parts are also presented. A Solid Works Simulation was also conducted on the stresses in the shafts and the results are presented. This design is an innovative solution which offers a user friendly interface. The design is also environmentally friendly, ecologically sound and safe to use.
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Designs of temperature measuring device for a re-configured milling machine
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Friction stir welding , Milling machines
- Type: Article
- Identifier: uj:4876 , http://hdl.handle.net/10210/12552
- Description: The design of temperature measuring approach for a re-configured milling machine to produce friction stir welds is reported in this paper. The product design specifications for the redesigning of a milling machine were first outlined and the ranking criteria were determined. Three different concepts were generated for the temperature measurement on the reconfigured system and the preferred or the best concept was selected based on the set design ranking criteria. Further simulation and performance analysis was then conducted on the concept. The Infrared Thermography (IRT) concept was selected for the temperature measurement among other concepts generated because it is an ideal and most effective system of measurement in this regard.
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Friction stir welding , Milling machines
- Type: Article
- Identifier: uj:4876 , http://hdl.handle.net/10210/12552
- Description: The design of temperature measuring approach for a re-configured milling machine to produce friction stir welds is reported in this paper. The product design specifications for the redesigning of a milling machine were first outlined and the ranking criteria were determined. Three different concepts were generated for the temperature measurement on the reconfigured system and the preferred or the best concept was selected based on the set design ranking criteria. Further simulation and performance analysis was then conducted on the concept. The Infrared Thermography (IRT) concept was selected for the temperature measurement among other concepts generated because it is an ideal and most effective system of measurement in this regard.
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Effect of number of laser scans on the corrosion behavior of laser formed titanium alloy
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2014
- Subjects: Titanium alloys , Laser beam formation
- Type: Article
- Identifier: uj:4749 , http://hdl.handle.net/10210/11735
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2014
- Subjects: Titanium alloys , Laser beam formation
- Type: Article
- Identifier: uj:4749 , http://hdl.handle.net/10210/11735
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Effect of punch stroke on deformation during sheet forming through finite element
- Akinlabi, Stephen A., Akinlabi, Esther Titilayo
- Authors: Akinlabi, Stephen A. , Akinlabi, Esther Titilayo
- Date: 2017
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/243839 , uj:25207 , Citation: Akinlabi, S. & Akinlabi, E.T. 2017. Effect of punch stroke on deformation during sheet forming through finite element.
- Description: Abstract: Forming is one of the traditional methods of making shapes, bends and curvature in metallic components during a fabrication process. Mechanical forming, in particular, employs the use of a punch, which is pressed against the sheet material to be deformed into a die by the application of an external force. This study reports on the finite element analysis of the effects of punch stroke on the resulting sheet deformation, which is directly a function of the structural integrity of the formed components for possible application in the automotive industry. The results show that punch stroke is directly proportional to the resulting bend angle of the formed components. It was further revealed that the developed plastic strain increases as the punch stroke increases.
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- Authors: Akinlabi, Stephen A. , Akinlabi, Esther Titilayo
- Date: 2017
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/243839 , uj:25207 , Citation: Akinlabi, S. & Akinlabi, E.T. 2017. Effect of punch stroke on deformation during sheet forming through finite element.
- Description: Abstract: Forming is one of the traditional methods of making shapes, bends and curvature in metallic components during a fabrication process. Mechanical forming, in particular, employs the use of a punch, which is pressed against the sheet material to be deformed into a die by the application of an external force. This study reports on the finite element analysis of the effects of punch stroke on the resulting sheet deformation, which is directly a function of the structural integrity of the formed components for possible application in the automotive industry. The results show that punch stroke is directly proportional to the resulting bend angle of the formed components. It was further revealed that the developed plastic strain increases as the punch stroke increases.
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Effect of rotational speed on joint inegrity of friction stir lap welded aluminium
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2016
- Subjects: Friction stir welding , Aluminum , Rotational speed
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93262 , uj:20326 , Citation: Akinlabi, E.T. & Akinlabi, S.A. 2016. Effect of rotational speed on joint inegrity of friction stir lap welded aluminium.
- Description: Abstract: Friction stir welding is a newly developed solid state welding process, which was developed by The Welding Institute in the year 1991. The development of FSW has allowed the process to be used in different applications for different industries, which include aerospace and automobile industry. Due to the increase in the demand of high strength and low weight components in different manufacturing applications, there is a need for using pure aluminium and its alloys in lap configuration. Research studies are required to characterize and obtain optimum process parameters, which can be used to produce good quality lap welds. This paper reports lap welded 1050 Aluminium Alloy using friction stir welding process and established the effect of rotational speed on the joint integrity of the welds. The welds were produced by varying the rotational speed in the range of 1200 and 2000 rpm, and maintaining the traverse speed constant at 150 mm/min. The welds were characterized through microstructural evaluation, microhardness profiling and tensile testing in order to determine the joint integrity of the welds. The results from the macrograph of the welded joints, show a basin shaped nugget resulting from the stirring of the tool during the welding process. Fine and equiaxed grains characterized the microstructure in the stirred zone, which was a result of a dynamic recrystallization. The tensile test data revealed that as the tool rotational speed was increased, the fracture strength also increases, the highest value of the fracture strength was 195 N/mm and was found on the welds produced at 2000 rpm. High Vickers microhardness values were measured at the nugget zone with the highest value found to be 31.88 HV. It was revealed that the welds produced at the rotational speed of 2000 rpm exhibited the optimum welding parameters to join 1050 Aluminium Alloy.
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2016
- Subjects: Friction stir welding , Aluminum , Rotational speed
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93262 , uj:20326 , Citation: Akinlabi, E.T. & Akinlabi, S.A. 2016. Effect of rotational speed on joint inegrity of friction stir lap welded aluminium.
- Description: Abstract: Friction stir welding is a newly developed solid state welding process, which was developed by The Welding Institute in the year 1991. The development of FSW has allowed the process to be used in different applications for different industries, which include aerospace and automobile industry. Due to the increase in the demand of high strength and low weight components in different manufacturing applications, there is a need for using pure aluminium and its alloys in lap configuration. Research studies are required to characterize and obtain optimum process parameters, which can be used to produce good quality lap welds. This paper reports lap welded 1050 Aluminium Alloy using friction stir welding process and established the effect of rotational speed on the joint integrity of the welds. The welds were produced by varying the rotational speed in the range of 1200 and 2000 rpm, and maintaining the traverse speed constant at 150 mm/min. The welds were characterized through microstructural evaluation, microhardness profiling and tensile testing in order to determine the joint integrity of the welds. The results from the macrograph of the welded joints, show a basin shaped nugget resulting from the stirring of the tool during the welding process. Fine and equiaxed grains characterized the microstructure in the stirred zone, which was a result of a dynamic recrystallization. The tensile test data revealed that as the tool rotational speed was increased, the fracture strength also increases, the highest value of the fracture strength was 195 N/mm and was found on the welds produced at 2000 rpm. High Vickers microhardness values were measured at the nugget zone with the highest value found to be 31.88 HV. It was revealed that the welds produced at the rotational speed of 2000 rpm exhibited the optimum welding parameters to join 1050 Aluminium Alloy.
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Effects of processing parameters on the corrosion properties of dissimilar friction stir welds of aluminium and copper
- Akinlabi, Esther Titilayo, Anthony, Andrews, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Anthony, Andrews , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Aluminium alloy , Copper , Corrosion , Friction stir welding
- Type: Article
- Identifier: uj:5019 , http://hdl.handle.net/10210/13159
- Description: The influence of friction stir welding processing parameters on dissimilar joints conducted between aluminium alloy (AA5754) and commercially pure copper (C11000) was studied. The welds were produced by varying the rotational speed from 600 to 1200 r/min and the feed rate from 50 to 300 mm/min. The resulting microstructure and the corrosion properties of the welds produced were studied. It was found that the joint interfacial regions of the welds were characterized by interlayers of aluminium and copper. The corrosion tests revealed that the corrosion resistance of the welds was improved as the rotational speed was increased. The corrosion rates of the welds compared to the base metals were improved compared with Cu and decreased slightly compared with the aluminium alloy. The lowest corrosion rate was obtained at welds produced at rotational speed of 950 r/min and feed rate of 300 mm/min which corresponds to a weld produced at a low heat input.
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- Authors: Akinlabi, Esther Titilayo , Anthony, Andrews , Akinlabi, Stephen A.
- Date: 2013
- Subjects: Aluminium alloy , Copper , Corrosion , Friction stir welding
- Type: Article
- Identifier: uj:5019 , http://hdl.handle.net/10210/13159
- Description: The influence of friction stir welding processing parameters on dissimilar joints conducted between aluminium alloy (AA5754) and commercially pure copper (C11000) was studied. The welds were produced by varying the rotational speed from 600 to 1200 r/min and the feed rate from 50 to 300 mm/min. The resulting microstructure and the corrosion properties of the welds produced were studied. It was found that the joint interfacial regions of the welds were characterized by interlayers of aluminium and copper. The corrosion tests revealed that the corrosion resistance of the welds was improved as the rotational speed was increased. The corrosion rates of the welds compared to the base metals were improved compared with Cu and decreased slightly compared with the aluminium alloy. The lowest corrosion rate was obtained at welds produced at rotational speed of 950 r/min and feed rate of 300 mm/min which corresponds to a weld produced at a low heat input.
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Evaluating operational challenges of road freight system
- Akinlabi, Stephen A., Mbohwa, Charles
- Authors: Akinlabi, Stephen A. , Mbohwa, Charles
- Date: 2016
- Subjects: Operational challenges , Road freight
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/214831 , uj:21330 , Citation: Akinlabi, S.A & Mbohwa, C. 2016. Evaluating operational challenges of road freight system.
- Description: Abstract: This study evaluates operational challenges of road freight during the transportation of goods in Transnet. South African roads are congested with trucks on every highway across the country leading to an increase in traffic congestion, damaged roads and air pollution. The results of this work reveal some of the operational challenges such as the poor state of the road infrastructure, traffic congestion, poor maintenance schedule and strategy, and also work absenteeism. All these consequently affect the optimal delivery of goods to customers as required.
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- Authors: Akinlabi, Stephen A. , Mbohwa, Charles
- Date: 2016
- Subjects: Operational challenges , Road freight
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/214831 , uj:21330 , Citation: Akinlabi, S.A & Mbohwa, C. 2016. Evaluating operational challenges of road freight system.
- Description: Abstract: This study evaluates operational challenges of road freight during the transportation of goods in Transnet. South African roads are congested with trucks on every highway across the country leading to an increase in traffic congestion, damaged roads and air pollution. The results of this work reveal some of the operational challenges such as the poor state of the road infrastructure, traffic congestion, poor maintenance schedule and strategy, and also work absenteeism. All these consequently affect the optimal delivery of goods to customers as required.
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Evaluating operational efficiency of rail freight volumes
- Madubanya, Julliet, Akinlabi, Stephen A., Mbohwa, Charles
- Authors: Madubanya, Julliet , Akinlabi, Stephen A. , Mbohwa, Charles
- Date: 2016
- Subjects: Operational efficiency , Freight volumes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/215037 , uj:21356 , Citation: Madubanya, J., Akinlabi, S & Mbohwa, C. 2016. Evaluating operational efficiency of rail freight volumes.
- Description: Abstract: South African roads are congested with trucks on every highway in the country leading to traffic congestion, damaged roads and pollution. Railway transportation can assist in eliminating or reducing these problems occurring on our roads. Rail traffic is decreasing because of the operational inefficiencies and this make customers unhappy and taking their business to road transportation. This paper is about how freight volumes are lost from rail to road organizations. This was conducted by looking at the operational inefficiencies experienced at both rail and road organizations. Any organization has its own plan or strategy on how to satisfy the customer and reach its target, but it is the service that they render to their customers that will determine if the organization will reach its target and at the same time satisfy the customer.
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- Authors: Madubanya, Julliet , Akinlabi, Stephen A. , Mbohwa, Charles
- Date: 2016
- Subjects: Operational efficiency , Freight volumes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/215037 , uj:21356 , Citation: Madubanya, J., Akinlabi, S & Mbohwa, C. 2016. Evaluating operational efficiency of rail freight volumes.
- Description: Abstract: South African roads are congested with trucks on every highway in the country leading to traffic congestion, damaged roads and pollution. Railway transportation can assist in eliminating or reducing these problems occurring on our roads. Rail traffic is decreasing because of the operational inefficiencies and this make customers unhappy and taking their business to road transportation. This paper is about how freight volumes are lost from rail to road organizations. This was conducted by looking at the operational inefficiencies experienced at both rail and road organizations. Any organization has its own plan or strategy on how to satisfy the customer and reach its target, but it is the service that they render to their customers that will determine if the organization will reach its target and at the same time satisfy the customer.
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Evaluation of structural integrity of laser formed steel sheets for possible load bearing applications
- Akinlabi, Stephen A., Shukla, M.
- Authors: Akinlabi, Stephen A. , Shukla, M.
- Date: 2016
- Subjects: Structural integrity , Laser forming , Microstructural evolution
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/215436 , uj:21417 , Citation: Akinlabi, S.A & Shukla, M. 2016. Evaluation of structural integrity of laser formed steel sheets for possible load bearing applications.
- Description: Abstract: Steel is a well-known material for various manufacturing applications because of its unique properties such as great formability and durability, good tensile and yield strength and good thermal conductivity. This paper reports on the evaluation of the structural integrity of laser formed steel sheets for possible load carrying applications. The tensile tests conducted revealed 46% elongation while the yield strength of the laser formed components were enhanced with about 18%. Furthermore, elongated grain structures were observed in the micrographs of the three components formed at the maximum parameter setting. It was revealed that this elongation varied indirectly to the applied line energy. The measured grain sizes further showed that the components formed at the optimized maximum process parameter window were characterized by smaller grain structures with about 60% of the grain sizes of the parent material. A progressive increase in the micro Vickers hardness of about 40% was also observed in the three laser formed components in comparison to the parent material. The analysis of the residual stresses conducted in this study revealed that the changes in the residual stresses are a function of the process condition to which the samples were subjected...
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- Authors: Akinlabi, Stephen A. , Shukla, M.
- Date: 2016
- Subjects: Structural integrity , Laser forming , Microstructural evolution
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/215436 , uj:21417 , Citation: Akinlabi, S.A & Shukla, M. 2016. Evaluation of structural integrity of laser formed steel sheets for possible load bearing applications.
- Description: Abstract: Steel is a well-known material for various manufacturing applications because of its unique properties such as great formability and durability, good tensile and yield strength and good thermal conductivity. This paper reports on the evaluation of the structural integrity of laser formed steel sheets for possible load carrying applications. The tensile tests conducted revealed 46% elongation while the yield strength of the laser formed components were enhanced with about 18%. Furthermore, elongated grain structures were observed in the micrographs of the three components formed at the maximum parameter setting. It was revealed that this elongation varied indirectly to the applied line energy. The measured grain sizes further showed that the components formed at the optimized maximum process parameter window were characterized by smaller grain structures with about 60% of the grain sizes of the parent material. A progressive increase in the micro Vickers hardness of about 40% was also observed in the three laser formed components in comparison to the parent material. The analysis of the residual stresses conducted in this study revealed that the changes in the residual stresses are a function of the process condition to which the samples were subjected...
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Experimental investigation of laser beam forming of titanium and statistical analysis of the effects of parameters on curvature
- Akinlabi, Stephen A., Akinlabi, Esther Titilayo
- Authors: Akinlabi, Stephen A. , Akinlabi, Esther Titilayo
- Date: 2013
- Subjects: Laser beam forming , Titanium alloys
- Type: Article
- Identifier: uj:4746 , ISSN 2078-0966 , http://hdl.handle.net/10210/11732
- Description: Laser beam forming, a non-contact manufacturing process has become a viable manufacturing process for shaping metallic components. The capability of laser beam forming and bending demands more experimental studies to identify an optimized parameter setting and the likely parameters influencing the formed curvature. This paper investigates experimental laser beam forming of Ti6Al4V titanium alloy using a 4.4 kW Nd: YAG laser and studied the effects of the process parameters on the formed curvature. It was established that an increase in both the laser beam power and the number of scan tracks reduces the radius of curvature in the formed sheets having a more dome shape. The scan speed on the other hand, achieved the same good curvature at a slower or reduced scan speed to allow enough laser – material interaction. Furthermore, both the ANOVA and the regression analysis confirmed the repeatability of the experimental data. A simple regression model was developed based on the known active parameters to determine approximate curvatures instead of running a series of experiments.
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- Authors: Akinlabi, Stephen A. , Akinlabi, Esther Titilayo
- Date: 2013
- Subjects: Laser beam forming , Titanium alloys
- Type: Article
- Identifier: uj:4746 , ISSN 2078-0966 , http://hdl.handle.net/10210/11732
- Description: Laser beam forming, a non-contact manufacturing process has become a viable manufacturing process for shaping metallic components. The capability of laser beam forming and bending demands more experimental studies to identify an optimized parameter setting and the likely parameters influencing the formed curvature. This paper investigates experimental laser beam forming of Ti6Al4V titanium alloy using a 4.4 kW Nd: YAG laser and studied the effects of the process parameters on the formed curvature. It was established that an increase in both the laser beam power and the number of scan tracks reduces the radius of curvature in the formed sheets having a more dome shape. The scan speed on the other hand, achieved the same good curvature at a slower or reduced scan speed to allow enough laser – material interaction. Furthermore, both the ANOVA and the regression analysis confirmed the repeatability of the experimental data. A simple regression model was developed based on the known active parameters to determine approximate curvatures instead of running a series of experiments.
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Fracture location characterizations of dissimilar friction stir welds.
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2011
- Subjects: Fracture location , Friction stir welding , Intermetallics , Metallography
- Type: Article
- Identifier: uj:5322 , http://hdl.handle.net/10210/8230
- Description: This paper reports the tensile fracture location characterizations of dissimilar friction stir welds between 5754 aluminium alloy and C11000 copper. The welds were produced using three shoulder diameter tools; namely, 15, 18 and 25 mm by varying the process parameters. The rotational speeds considered were 600, 950 and 1200 rpm while the feed rates employed were 50, 150 and 300 mm/min to represent the low, medium and high settings respectively. The tensile fracture locations were evaluated using the optical microscope to identify the fracture locations and were characterized. It was observed that 70% of the tensile samples failed in the Thermo Mechanically Affected Zone (TMAZ) of copper at the weld joints. Further evaluation of the fracture surfaces of the pulled tensile samples revealed that welds with low Ultimate Tensile Strength either have defects or intermetallics present at their joint interfaces.
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2011
- Subjects: Fracture location , Friction stir welding , Intermetallics , Metallography
- Type: Article
- Identifier: uj:5322 , http://hdl.handle.net/10210/8230
- Description: This paper reports the tensile fracture location characterizations of dissimilar friction stir welds between 5754 aluminium alloy and C11000 copper. The welds were produced using three shoulder diameter tools; namely, 15, 18 and 25 mm by varying the process parameters. The rotational speeds considered were 600, 950 and 1200 rpm while the feed rates employed were 50, 150 and 300 mm/min to represent the low, medium and high settings respectively. The tensile fracture locations were evaluated using the optical microscope to identify the fracture locations and were characterized. It was observed that 70% of the tensile samples failed in the Thermo Mechanically Affected Zone (TMAZ) of copper at the weld joints. Further evaluation of the fracture surfaces of the pulled tensile samples revealed that welds with low Ultimate Tensile Strength either have defects or intermetallics present at their joint interfaces.
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Friction stir welding of aluminium and copper : fracture surface characterizations
- Akinlabi, Esther Titilayo, Akinlabi, Stephen A.
- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2014
- Subjects: Aluminium , Copper , Fracture surfaces , Friction stir welding
- Type: Article
- Identifier: uj:4745 , ISSN 2078-0966 , http://hdl.handle.net/10210/11731
- Description: Butt welds of aluminium alloy and copper alloy were produced by Friction Stir Welding by varying the feed rate and keeping all other parameters constant. The final weld matrix was composed of welds produced by a constant rotational speed of 600 rpm and the feed rate varied between 50 and 300mm/min. The microstructure and fracture surfaces of the joint interfaces were investigated. The results revealed that the joint interface was characterised with mixed layers of both materials joined. The strongest weld was produced at the highest feed rate employed at 300 mm/min. The fracture surfaces were characterised with thin layers of intermetallic compounds and can be considered fit for practical applications.
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- Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
- Date: 2014
- Subjects: Aluminium , Copper , Fracture surfaces , Friction stir welding
- Type: Article
- Identifier: uj:4745 , ISSN 2078-0966 , http://hdl.handle.net/10210/11731
- Description: Butt welds of aluminium alloy and copper alloy were produced by Friction Stir Welding by varying the feed rate and keeping all other parameters constant. The final weld matrix was composed of welds produced by a constant rotational speed of 600 rpm and the feed rate varied between 50 and 300mm/min. The microstructure and fracture surfaces of the joint interfaces were investigated. The results revealed that the joint interface was characterised with mixed layers of both materials joined. The strongest weld was produced at the highest feed rate employed at 300 mm/min. The fracture surfaces were characterised with thin layers of intermetallic compounds and can be considered fit for practical applications.
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