Preparation, chemical composition, characterization, and properties of Napier grass paper sheets
- Reddy, K. Obi, Maheswari, C. Uma, Shukla, M., Muzenda, Edison
- Authors: Reddy, K. Obi , Maheswari, C. Uma , Shukla, M. , Muzenda, Edison
- Date: 2014
- Subjects: Pulp and papermaking , Napier Grass fibers
- Type: Article
- Identifier: uj:4767 , ISSN 1520-5754 , http://hdl.handle.net/10210/11942
- Description: In this study, perennial fast growth Napier grass fibers were used for pulp and papermaking. Chlorination and alkaline processes were carried out using sodium chlorite and sodium hydroxide respectively, for pulp extraction from Napier grass. Detailed chemical composition analysis of the Napier grass fibers and the extracted pulp was carried out and a comparison with other perennial grasses was made. The extracted fibers and pulp obtained from Napier grass were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. The physical, optical, and mechanical properties of Napier grass pulp handmade paper sheets produced in the laboratory were investigated by finding the opacity, brightness, tensile index, breaking length, and burst index. Handmade paper sheets made from Napier grass pulp were compared to paper made from other perennial grasses. The superior properties of paper produced from Napier grass pulp indicate the suitability of Napier grass as an alternative non-wood source for papermaking.
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- Authors: Reddy, K. Obi , Maheswari, C. Uma , Shukla, M. , Muzenda, Edison
- Date: 2014
- Subjects: Pulp and papermaking , Napier Grass fibers
- Type: Article
- Identifier: uj:4767 , ISSN 1520-5754 , http://hdl.handle.net/10210/11942
- Description: In this study, perennial fast growth Napier grass fibers were used for pulp and papermaking. Chlorination and alkaline processes were carried out using sodium chlorite and sodium hydroxide respectively, for pulp extraction from Napier grass. Detailed chemical composition analysis of the Napier grass fibers and the extracted pulp was carried out and a comparison with other perennial grasses was made. The extracted fibers and pulp obtained from Napier grass were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy. The physical, optical, and mechanical properties of Napier grass pulp handmade paper sheets produced in the laboratory were investigated by finding the opacity, brightness, tensile index, breaking length, and burst index. Handmade paper sheets made from Napier grass pulp were compared to paper made from other perennial grasses. The superior properties of paper produced from Napier grass pulp indicate the suitability of Napier grass as an alternative non-wood source for papermaking.
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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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Bioceramic hydroxyapatite coating fabricated on TI-6AL-4V using Nd:YAG laser
- Tlotleng, M., Akinlabi, Esther Titilayo, Shukla, M., Pityana, S., Mathebula, T., Chauke, L.
- Authors: Tlotleng, M. , Akinlabi, Esther Titilayo , Shukla, M. , Pityana, S. , Mathebula, T. , Chauke, L.
- Date: 2014
- Subjects: Bioceramic hydroxyapatite coating , Nd:YAG laser
- Type: Article
- Identifier: uj:5015 , ISSN 978-0-7972-1532-0 , http://hdl.handle.net/10210/13155
- Description: A method of synthesising a biocompatible HAP coating is presented. In the current study, Nd:YAG laser was used to directly melt pre-place HAP powder beds on Ti-6Al-4V. The processing parameters used were 750 W laser power, 5 mm/s scanning speed and 27° inclined beam plane. The coating was studied under white light and scanning electron microscope where it was possible to characterise the microstructures. The produced coating was characterised of mixed morphologies of HAP, short and elongated titanium needles at the surface while in the middle of the coating dendrite trunks without arms were observed. This observation is related to the heat inputs, dilution and melting of the substrate and powder during processing. The absence of the arms growing from the trunks indicated low heat inputs. In addition, the microstructure of the HAP after soaking in Hanks’ solution indicated octagonal and hexagonal crystals of HAP. The hardness values indicated good metallurgical bonding at the interface. In conclusion, this study was successful in fabricating a desirable coating of HAP on Ti-6Al-4V for biomedical applications. This work highlights that even though laser power and scanning speed are predominantly influential parameter settings, it is also necessary to consider the angle at which the laser beam is scanned across the material.
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- Authors: Tlotleng, M. , Akinlabi, Esther Titilayo , Shukla, M. , Pityana, S. , Mathebula, T. , Chauke, L.
- Date: 2014
- Subjects: Bioceramic hydroxyapatite coating , Nd:YAG laser
- Type: Article
- Identifier: uj:5015 , ISSN 978-0-7972-1532-0 , http://hdl.handle.net/10210/13155
- Description: A method of synthesising a biocompatible HAP coating is presented. In the current study, Nd:YAG laser was used to directly melt pre-place HAP powder beds on Ti-6Al-4V. The processing parameters used were 750 W laser power, 5 mm/s scanning speed and 27° inclined beam plane. The coating was studied under white light and scanning electron microscope where it was possible to characterise the microstructures. The produced coating was characterised of mixed morphologies of HAP, short and elongated titanium needles at the surface while in the middle of the coating dendrite trunks without arms were observed. This observation is related to the heat inputs, dilution and melting of the substrate and powder during processing. The absence of the arms growing from the trunks indicated low heat inputs. In addition, the microstructure of the HAP after soaking in Hanks’ solution indicated octagonal and hexagonal crystals of HAP. The hardness values indicated good metallurgical bonding at the interface. In conclusion, this study was successful in fabricating a desirable coating of HAP on Ti-6Al-4V for biomedical applications. This work highlights that even though laser power and scanning speed are predominantly influential parameter settings, it is also necessary to consider the angle at which the laser beam is scanned across the material.
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Effect of surface treatment on performance of tamarind fiber-epoxy composites
- Maheswari, C. Uma, Reddy, K. Obi, Muzenda, Edison, Shukla, M.
- Authors: Maheswari, C. Uma , Reddy, K. Obi , Muzenda, Edison , Shukla, M.
- Date: 2012
- Subjects: Fiber composites , Fibre-reinforced epoxy
- Type: Article
- Identifier: uj:6063 , http://hdl.handle.net/10210/10482
- Description: Randomly oriented short Tamarind fibre reinforced Epoxy composites were prepared by hand lay up process. To improve the surface, these fibers were treated with alkali (sodium hydroxide) and silane (3-aminopropyltriethoxy silane). The effects of alkali and silane treatment of fibers on tensile and flexural properties of the composites were investigated. Mechanical test results show that alkali and silane treatment significantly improves the tensile, flexural and impact properties of Tamarind fiber epoxy composites. Scanning electron microscopy (SEM) investigations show that surface modifications improve the fiber/matrix adhesion.
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- Authors: Maheswari, C. Uma , Reddy, K. Obi , Muzenda, Edison , Shukla, M.
- Date: 2012
- Subjects: Fiber composites , Fibre-reinforced epoxy
- Type: Article
- Identifier: uj:6063 , http://hdl.handle.net/10210/10482
- Description: Randomly oriented short Tamarind fibre reinforced Epoxy composites were prepared by hand lay up process. To improve the surface, these fibers were treated with alkali (sodium hydroxide) and silane (3-aminopropyltriethoxy silane). The effects of alkali and silane treatment of fibers on tensile and flexural properties of the composites were investigated. Mechanical test results show that alkali and silane treatment significantly improves the tensile, flexural and impact properties of Tamarind fiber epoxy composites. Scanning electron microscopy (SEM) investigations show that surface modifications improve the fiber/matrix adhesion.
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Effect of chemicals treatment and fiber loading on mechanical properties of borassus (Toddy palm) fiber/epoxy composites
- Reddy, K. Obi, Maheswari, C. Uma, Reddy, K. Ramakrishna, Shukla, M., Muzenda, E., Rajulu, A. Varada
- Authors: Reddy, K. Obi , Maheswari, C. Uma , Reddy, K. Ramakrishna , Shukla, M. , Muzenda, E. , Rajulu, A. Varada
- Date: 2015
- Subjects: Borassus fruit fiber , Chemical treatments , Spectroscopy
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/73565 , uj:18426 , Citation: Reddy, K.O. et al. 2015. Effect of chemicals treatment and fiber loading on mechanical properties of borassus (Toddy palm) fiber/epoxy composites.
- Description: Abstract: The aim of the present study was to investigate and compare the mechanical properties of untreated and chemically modified Borassus fiber reinforced epoxy composites. Composites were prepared by hand lay-up process by reinforcing Borassus fibers with epoxy matrix. To improve the fiber-matrix adhesion properties, alkali (NaOH), and alkali combined with silane (3- aminopropyltriethoxysilane) treatments on the fibers surface were carried out. Examinations through Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were conducted to investigate the structural and physical properties of the Borassus fibers. Tensile properties such as modulus and strength of the composites made by chemically modified and untreated Borassus fibers were studied using a Universal Testing Machine (UTM). Based on the experimental results, it was found that the tensile properties of the Borassus reinforced epoxy composites were significantly improved, as compared with the neat epoxy. It was also found that the fiber treated with combination of alkali and silane exhibited superior mechanical properties as compared with alkali and untreated fiber composites. The nature of fiber/matrix interface was examined through SEM of cryo-fractured samples. Chemical resistance of composites was also found to be improved with chemically modified fiber composites.
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- Authors: Reddy, K. Obi , Maheswari, C. Uma , Reddy, K. Ramakrishna , Shukla, M. , Muzenda, E. , Rajulu, A. Varada
- Date: 2015
- Subjects: Borassus fruit fiber , Chemical treatments , Spectroscopy
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/73565 , uj:18426 , Citation: Reddy, K.O. et al. 2015. Effect of chemicals treatment and fiber loading on mechanical properties of borassus (Toddy palm) fiber/epoxy composites.
- Description: Abstract: The aim of the present study was to investigate and compare the mechanical properties of untreated and chemically modified Borassus fiber reinforced epoxy composites. Composites were prepared by hand lay-up process by reinforcing Borassus fibers with epoxy matrix. To improve the fiber-matrix adhesion properties, alkali (NaOH), and alkali combined with silane (3- aminopropyltriethoxysilane) treatments on the fibers surface were carried out. Examinations through Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were conducted to investigate the structural and physical properties of the Borassus fibers. Tensile properties such as modulus and strength of the composites made by chemically modified and untreated Borassus fibers were studied using a Universal Testing Machine (UTM). Based on the experimental results, it was found that the tensile properties of the Borassus reinforced epoxy composites were significantly improved, as compared with the neat epoxy. It was also found that the fiber treated with combination of alkali and silane exhibited superior mechanical properties as compared with alkali and untreated fiber composites. The nature of fiber/matrix interface was examined through SEM of cryo-fractured samples. Chemical resistance of composites was also found to be improved with chemically modified fiber composites.
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Tyre derived fuel as an alternative fuel for CI engines
- Pilusa, T.J, Shukla, M., Muzenda, E.
- Authors: Pilusa, T.J , Shukla, M. , Muzenda, E.
- Date: 2013
- Subjects: Tyre derived fuel-diesel , Waste tyre pyrolysis , Alternative fuel , Crude oil
- Type: Article
- Identifier: uj:4957 , http://hdl.handle.net/10210/13058
- Description: The study presented in this article investigated the potential use of tyre derived fuel-diesel blends as an alternative low cost fuel for compression ignition engines. A short review was conducted on waste tyre pyrolysis technology and its benefits in addressing the waste tyre management while providing an alternative usable fuel for diesel engines. Crude oil obtained from slow pyrolysis of waste tyres was distillated and its respective fractions were characterized and blended with low sulphur diesel fuel for fuelling a stationery truck engine linked to a hydraulic dynamometer. The test results revealed that fuel fraction blends with low sulphur diesel can be used to fuel a conventional compression ignition engine, however special attention is required to manage the exhausts emission due to high concentration of sulphur dioxide. There is no doubt that tyre derived fuel has a potential as future alternative fuel for compression ignition engines.
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- Authors: Pilusa, T.J , Shukla, M. , Muzenda, E.
- Date: 2013
- Subjects: Tyre derived fuel-diesel , Waste tyre pyrolysis , Alternative fuel , Crude oil
- Type: Article
- Identifier: uj:4957 , http://hdl.handle.net/10210/13058
- Description: The study presented in this article investigated the potential use of tyre derived fuel-diesel blends as an alternative low cost fuel for compression ignition engines. A short review was conducted on waste tyre pyrolysis technology and its benefits in addressing the waste tyre management while providing an alternative usable fuel for diesel engines. Crude oil obtained from slow pyrolysis of waste tyres was distillated and its respective fractions were characterized and blended with low sulphur diesel fuel for fuelling a stationery truck engine linked to a hydraulic dynamometer. The test results revealed that fuel fraction blends with low sulphur diesel can be used to fuel a conventional compression ignition engine, however special attention is required to manage the exhausts emission due to high concentration of sulphur dioxide. There is no doubt that tyre derived fuel has a potential as future alternative fuel for compression ignition engines.
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Effect of surface treatment on performance of tamarind fiber-epoxy composites
- Maheswari, C. Uma, Reddy, K. Obi, Muzenda, Edison, Shukla, M.
- Authors: Maheswari, C. Uma , Reddy, K. Obi , Muzenda, Edison , Shukla, M.
- Date: 2012
- Subjects: Fiber composites , Tamarind fibre reinforced epoxy
- Type: Article
- Identifier: uj:6025 , ISBN 978-93-82242-17-8 , http://hdl.handle.net/10210/10045
- Description: Randomly oriented short Tamarind fibre reinforced epoxy composites were prepared by hand lay up process. To improve the surface, these fibers were treated with alkali (sodium hydroxide) and silane (3-aminopropyltriethoxy silane). The effects of alkali and silane treatment of fibers on tensile and flexural properties of the composites were investigated. Mechanical test results show that alkali and silane treatment significantly improves the tensile, flexural and impact properties of Tamarind fiber epoxy composites. Scanning electron microscopy (SEM) investigations show that surface modifications improve the fiber/matrix adhesion.
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- Authors: Maheswari, C. Uma , Reddy, K. Obi , Muzenda, Edison , Shukla, M.
- Date: 2012
- Subjects: Fiber composites , Tamarind fibre reinforced epoxy
- Type: Article
- Identifier: uj:6025 , ISBN 978-93-82242-17-8 , http://hdl.handle.net/10210/10045
- Description: Randomly oriented short Tamarind fibre reinforced epoxy composites were prepared by hand lay up process. To improve the surface, these fibers were treated with alkali (sodium hydroxide) and silane (3-aminopropyltriethoxy silane). The effects of alkali and silane treatment of fibers on tensile and flexural properties of the composites were investigated. Mechanical test results show that alkali and silane treatment significantly improves the tensile, flexural and impact properties of Tamarind fiber epoxy composites. Scanning electron microscopy (SEM) investigations show that surface modifications improve the fiber/matrix adhesion.
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Characterization of laser deposited Ti6Al4V/TiC composite powders on a Ti6Al4V substrate
- Mahamood, R. M., Akinlabi, Esther Titilayo, Shukla, M., Pityana, S.
- Authors: Mahamood, R. M. , Akinlabi, Esther Titilayo , Shukla, M. , Pityana, S.
- Date: 2014
- Subjects: Laser metal deposition , Material characterization
- Type: Article
- Identifier: uj:4986 , http://hdl.handle.net/10210/13118
- Description: This paper reports the material characterization of Ti6Al4V/TiC composite produced by laser metal deposition. The Ti6Al4V/TiC composites were deposited with a composition ratio of 50 wt.% Ti64l4V and 50 wt.% TiC. The depositions were achieved by delivering the two powders from a powder feeder consisting of two different hoppers and each hopper contains each of the powders. A total of eight experiments were performed, the scanning speed was kept constant at 0.005 m/s and the laser power varied between 0.4 and 3.2 kW. The gas flow rate and the powder flow rates were also kept at constant settings of 1.44 g/min and 1 l/min respectively for each hopper. The deposits were laterally sectioned, metallographically prepared and characterized through microstructural evaluation, microhardness and wear resistance performance. The effects of varying the laser power on the resulting properties of the composites were studied extensively. The microstructure consists of un-melted carbide (UMC) in the matrix of alpha and prior beta grain structure of Ti6Al4V, and in varying degrees in all the samples. The results showed that the microhardness and the wear resistance performance were dependent on the laser power.
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- Authors: Mahamood, R. M. , Akinlabi, Esther Titilayo , Shukla, M. , Pityana, S.
- Date: 2014
- Subjects: Laser metal deposition , Material characterization
- Type: Article
- Identifier: uj:4986 , http://hdl.handle.net/10210/13118
- Description: This paper reports the material characterization of Ti6Al4V/TiC composite produced by laser metal deposition. The Ti6Al4V/TiC composites were deposited with a composition ratio of 50 wt.% Ti64l4V and 50 wt.% TiC. The depositions were achieved by delivering the two powders from a powder feeder consisting of two different hoppers and each hopper contains each of the powders. A total of eight experiments were performed, the scanning speed was kept constant at 0.005 m/s and the laser power varied between 0.4 and 3.2 kW. The gas flow rate and the powder flow rates were also kept at constant settings of 1.44 g/min and 1 l/min respectively for each hopper. The deposits were laterally sectioned, metallographically prepared and characterized through microstructural evaluation, microhardness and wear resistance performance. The effects of varying the laser power on the resulting properties of the composites were studied extensively. The microstructure consists of un-melted carbide (UMC) in the matrix of alpha and prior beta grain structure of Ti6Al4V, and in varying degrees in all the samples. The results showed that the microhardness and the wear resistance performance were dependent on the laser power.
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Forming behaviour of steel sheets after mechanical and laser beam forming
- Akinlabi, Esther Titilayo, Shukla, M., Akinlabi, S. A., Kanyanga, S. B., Chizyuka, C. M.
- Authors: Akinlabi, Esther Titilayo , Shukla, M. , Akinlabi, S. A. , Kanyanga, S. B. , Chizyuka, C. M.
- Date: 2014
- Subjects: Laser beam forming , Mechanical forming , Microhardness , Microstructure , Tensile testing , Steel plates - Mechanical properties
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/379024 , uj:4998 , http://hdl.handle.net/10210/13136
- Description: This paper reports the influencing factors and the characteristic behaviour of steel plates during both the mechanical forming and laser beam forming processes. Samples of the steel sheets were mechanically bent to 120 mm curvatures using a 20 ton capacity eccentric mechanical press at room temperature and also with the laser beam using a 4.4 kW Nd: YAG laser system at a scan speed of 1.9 m/min, beam diameter of 12 mm, laser power of 1.7 kW at 25% beam overlap using argon for cooling the irradiated surfaces. The chemical composition of both the as-received material and the formed samples were analysed by emission spectroscopy to quantify the changes in the elemental composition. The result shows a percentage increase in the carbon after the mechanical and laser forming processes when compared to the parent material. This can be attributed to the enhancement resulting from the forming processes. The formed samples were further characterized through microstructure, microhardness and tensile tests. The microstructural characterisation of the samples revealed that the grains of the mechanically formed and laser formed components are elongated, it was also observed that there is an increase in the pearlite grains of the laser formed components resulting from the thermal heating during the laser process. The microhardness profiles of the formed components showed that there is a significant percentage increase in the Vickers microhardness values of the laser formed samples when compared to the mechanically formed samples and with respect to the parent material. The laser beam forming process can be considered a more appropriate forming process in terms of the resulting material properties in this regard.
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- Authors: Akinlabi, Esther Titilayo , Shukla, M. , Akinlabi, S. A. , Kanyanga, S. B. , Chizyuka, C. M.
- Date: 2014
- Subjects: Laser beam forming , Mechanical forming , Microhardness , Microstructure , Tensile testing , Steel plates - Mechanical properties
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/379024 , uj:4998 , http://hdl.handle.net/10210/13136
- Description: This paper reports the influencing factors and the characteristic behaviour of steel plates during both the mechanical forming and laser beam forming processes. Samples of the steel sheets were mechanically bent to 120 mm curvatures using a 20 ton capacity eccentric mechanical press at room temperature and also with the laser beam using a 4.4 kW Nd: YAG laser system at a scan speed of 1.9 m/min, beam diameter of 12 mm, laser power of 1.7 kW at 25% beam overlap using argon for cooling the irradiated surfaces. The chemical composition of both the as-received material and the formed samples were analysed by emission spectroscopy to quantify the changes in the elemental composition. The result shows a percentage increase in the carbon after the mechanical and laser forming processes when compared to the parent material. This can be attributed to the enhancement resulting from the forming processes. The formed samples were further characterized through microstructure, microhardness and tensile tests. The microstructural characterisation of the samples revealed that the grains of the mechanically formed and laser formed components are elongated, it was also observed that there is an increase in the pearlite grains of the laser formed components resulting from the thermal heating during the laser process. The microhardness profiles of the formed components showed that there is a significant percentage increase in the Vickers microhardness values of the laser formed samples when compared to the mechanically formed samples and with respect to the parent material. The laser beam forming process can be considered a more appropriate forming process in terms of the resulting material properties in this regard.
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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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- 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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