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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Influence of laser power on the deposition Ti64l4V/W composite
- Ndou, Ndivhuwo, Akinlabi, Esther Titilayo, Pityana, Sisa
- Authors: Ndou, Ndivhuwo , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2016
- Subjects: Heat affected zone , Laser metal deposition
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/214837 , uj:21331 , Citation: Ndou, N., Akinlabi, E.T & Pityana, S. 2016. Influence of laser power on the deposition Ti64l4V/W composite.
- Description: Abstract: In this study of laser power on deposited of Ti64l4V/W was investigated. The energy flow rates were varied while every single other parameter were kept at a steady. The evolving microstructure and the hardness of the composites were studied and reported in this study. The study established that the laser metal deposition process is suitable for producing acceptable bonding between a deposited zone and a substrate zone. The hardness values of the deposits varied from 377HV to 719HV. The laser power directly influences the hardness and the microstructure. Scanning electron microscopy (SEM) was utilised to characterise the microstructure of the composite layer formed on the surface of the Ti6Al4V substrate. The microstructure of all the composite layers delivered by the LMD procedure has upgraded properties in connection to that of the Ti64l4V substrate.
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- Authors: Ndou, Ndivhuwo , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2016
- Subjects: Heat affected zone , Laser metal deposition
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/214837 , uj:21331 , Citation: Ndou, N., Akinlabi, E.T & Pityana, S. 2016. Influence of laser power on the deposition Ti64l4V/W composite.
- Description: Abstract: In this study of laser power on deposited of Ti64l4V/W was investigated. The energy flow rates were varied while every single other parameter were kept at a steady. The evolving microstructure and the hardness of the composites were studied and reported in this study. The study established that the laser metal deposition process is suitable for producing acceptable bonding between a deposited zone and a substrate zone. The hardness values of the deposits varied from 377HV to 719HV. The laser power directly influences the hardness and the microstructure. Scanning electron microscopy (SEM) was utilised to characterise the microstructure of the composite layer formed on the surface of the Ti6Al4V substrate. The microstructure of all the composite layers delivered by the LMD procedure has upgraded properties in connection to that of the Ti64l4V substrate.
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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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Non-destructive residual stress analysis and microstructural behaviour of laser deposited titanium and copper alloy
- Erinosho, Mutiu F., Akinlabi, Esther Titilayo
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo
- Date: 2017
- Subjects: Laser metal deposition , Microstructures , Residual stress
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/233517 , uj:23842 , Citation: Erinosho, M.F. & Akinlabi, E.T. 2017. Non-destructive residual stress analysis and microstructural behaviour of laser deposited titanium and copper alloy. 5th International Conference of Materials Processing and Characterization (ICMPC 2016).
- Description: Abstract: Titanium alloy (Grade 5) has been regarded as the most useful alloys for the aerospace applications, due to their light weight properties. The addition of copper to this alloy allows the improvement in the mechanical properties. The increase in the laser power has influenced the coarseness of the α-Ti lamella; and thus slows down the cooling rate during solidification. The X ray diffraction method has been used to analyse the residual stresses using the biaxial and shear-stressed model. Very infinitesimal microns were taken into consideration for the penetration depth. The results generated indicate that a decrease in the compressive residual stresses is attributed to the increase in the laser power and the variation of the heat input within the clad during processing. The differences in the thermal expansion with respect to the increase in the volume of deposition as the laser power increases have significant effect on the compressive residual stress.
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- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo
- Date: 2017
- Subjects: Laser metal deposition , Microstructures , Residual stress
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/233517 , uj:23842 , Citation: Erinosho, M.F. & Akinlabi, E.T. 2017. Non-destructive residual stress analysis and microstructural behaviour of laser deposited titanium and copper alloy. 5th International Conference of Materials Processing and Characterization (ICMPC 2016).
- Description: Abstract: Titanium alloy (Grade 5) has been regarded as the most useful alloys for the aerospace applications, due to their light weight properties. The addition of copper to this alloy allows the improvement in the mechanical properties. The increase in the laser power has influenced the coarseness of the α-Ti lamella; and thus slows down the cooling rate during solidification. The X ray diffraction method has been used to analyse the residual stresses using the biaxial and shear-stressed model. Very infinitesimal microns were taken into consideration for the penetration depth. The results generated indicate that a decrease in the compressive residual stresses is attributed to the increase in the laser power and the variation of the heat input within the clad during processing. The differences in the thermal expansion with respect to the increase in the volume of deposition as the laser power increases have significant effect on the compressive residual stress.
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Characterizing the effect of processing parameters on the porosity of laser deposited titanium alloy powder
- Mahamood, Rasheedat M., Akinlabi, Esther Titilayo, Shukla, Mukul, Pityana, Sisa
- Authors: Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo , Shukla, Mukul , Pityana, Sisa
- Date: 2014
- Subjects: Laser metal deposition , Medical implants , Porosity , Processing parameters , Titanium alloy
- Type: Article
- Identifier: uj:4739 , ISSN 2078-0966 , http://hdl.handle.net/10210/11725
- Description: Laser Metal Deposition (LMD) is an additive manufacturing technique that produces parts layer by layer directly from the Computer Aided Design (CAD) file. Highly customized parts with complex shapes such as medical implants can well be manufactured using the LMD process. LMD has been used to produce a wide range of patient specific (customized) parts. Porous parts are of particular importance as medical implants because they can potentially aid the healing process and proper integration of the implant with the body tissues. In this research porous samples of titanium alloy (Ti6Al4V) were produced using the LMD process. Spherical shaped Ti6Al4V powder of particle size ranging between 150 to 200 μm was used. The effect of laser power and scanning speed on the shape, size and degree of porosity of the deposited tracks was investigated. The results showed that as the laser power was increased and the scanning speed decreased, the degree of porosity was reduced. The size of the porosity was also found to reduce as the laser power was increased.
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- Authors: Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo , Shukla, Mukul , Pityana, Sisa
- Date: 2014
- Subjects: Laser metal deposition , Medical implants , Porosity , Processing parameters , Titanium alloy
- Type: Article
- Identifier: uj:4739 , ISSN 2078-0966 , http://hdl.handle.net/10210/11725
- Description: Laser Metal Deposition (LMD) is an additive manufacturing technique that produces parts layer by layer directly from the Computer Aided Design (CAD) file. Highly customized parts with complex shapes such as medical implants can well be manufactured using the LMD process. LMD has been used to produce a wide range of patient specific (customized) parts. Porous parts are of particular importance as medical implants because they can potentially aid the healing process and proper integration of the implant with the body tissues. In this research porous samples of titanium alloy (Ti6Al4V) were produced using the LMD process. Spherical shaped Ti6Al4V powder of particle size ranging between 150 to 200 μm was used. The effect of laser power and scanning speed on the shape, size and degree of porosity of the deposited tracks was investigated. The results showed that as the laser power was increased and the scanning speed decreased, the degree of porosity was reduced. The size of the porosity was also found to reduce as the laser power was increased.
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Surface effect of laser power on microstructural evolution and hardness behaviour of titanium matrix composites
- Ogunlana, Musibau O., Akinlabi, Esther Titilayo
- Authors: Ogunlana, Musibau O. , Akinlabi, Esther Titilayo
- Date: 2016
- Subjects: Boron carbide , Laser metal deposition , Titanium alloy
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/92390 , uj:20224 , Citation: Ogunlana, M.O., & Akinlabi, E.L. 2016. Surface effect of laser power on microstructural evolution and hardness behaviour of titanium matrix composites.
- Description: Abstract: In this paper, Titanium alloy (Ti6Al4V) powder and boron carbide (B4C) powder metal matrix composites (MMCs) were embedded on titanium alloy (Ti6Al4V) substrate using laser metal deposition (LMD). The laser power was varied between 800 W and 2400 W at an interval of 200 W while all other processing parameters were kept constant. The maximum capacity of the laser system is 3.0 KW which provides beam size of 4 mm for the control characterization of the deposited samples. The microstructural properties of the deposited samples were profound with α and β (intermetallic phase of α+β) of titanium alloy and boron carbide particles. The optical microscope (OM) was employed to characterise the grain sizes and microstructures. The microhardness were characterized using the Vickers’ hardness indenter in which the microhardness of the composites revealed an increase in the samples as the laser power increases. The hardness were observed to be between 371Hv and 471Hv for the cladded samples when compared to the substrate with approximately 360Hv.
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- Authors: Ogunlana, Musibau O. , Akinlabi, Esther Titilayo
- Date: 2016
- Subjects: Boron carbide , Laser metal deposition , Titanium alloy
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/92390 , uj:20224 , Citation: Ogunlana, M.O., & Akinlabi, E.L. 2016. Surface effect of laser power on microstructural evolution and hardness behaviour of titanium matrix composites.
- Description: Abstract: In this paper, Titanium alloy (Ti6Al4V) powder and boron carbide (B4C) powder metal matrix composites (MMCs) were embedded on titanium alloy (Ti6Al4V) substrate using laser metal deposition (LMD). The laser power was varied between 800 W and 2400 W at an interval of 200 W while all other processing parameters were kept constant. The maximum capacity of the laser system is 3.0 KW which provides beam size of 4 mm for the control characterization of the deposited samples. The microstructural properties of the deposited samples were profound with α and β (intermetallic phase of α+β) of titanium alloy and boron carbide particles. The optical microscope (OM) was employed to characterise the grain sizes and microstructures. The microhardness were characterized using the Vickers’ hardness indenter in which the microhardness of the composites revealed an increase in the samples as the laser power increases. The hardness were observed to be between 371Hv and 471Hv for the cladded samples when compared to the substrate with approximately 360Hv.
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Laser power and scanning speed influence on intermetallic and wear behaviour of laser metal deposited titanium alloy composite
- Mahamood, Rasheedat M., Akinlabi, Esther Titilayo
- Authors: Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo
- Date: 2016
- Subjects: Intermetallic , Laser metal deposition , Processing parameters
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/214836 , uj:21332 , Citation: Mohamood, R.M & Akinlabi, E.T. 2016. Laser power and scanning speed influence on intermetallic and wear behaviour of laser metal deposited titanium alloy composite.
- Description: Abstract: Ti6Al4V, an aerospace alloy, is the most widely produced titanium alloy because of its exciting properties such as high strength to weight ratio and excellent corrosion resistance properties. Despite these properties of this titanium alloy, the wear property is poor because of its chemical property that makes it react with other material it comes in contact with. Therefore, there is need for surface modification of the titanium alloy if it will be used in application where it will come in contact will other material in rubbing or sliding action. TiC has been used to improve the wear resistance property of titanium alloy with success. Laser metal deposition (LMD) process, an additive manufacturing process, is an advanced manufacturing process for achieving part with the desired surface property as well as for producing complex part directly from the three dimensional (3D) computer aided design (CAD) model of the part. Processing parameter has a great influence on the resulting properties of the deposited part using LMD. This research investigates the influence of laser power and scanning speed on the in-situ formation of titanium aluminide (Ti3Al) during laser metal deposition of TiC/Ti6Al4V composite and its overall effect on the wear resistance behaviour of the deposited composites. The laser power was changed between 1.8 and 3.0 kW and the scanning speed was changed between 0.05 and 0.1 m/s. It was found that, the intermetallic produced increased as the scanning speed was reduced from 0.1 to 0.05 m/s. The intermetallic formed at low scanning speed was found to decrease as the laser power was increased from 1.8 to 3.0 kW, while it was found to increase as the laser power was increased at higher scanning speed. The wear resistance property increases as the intermetallic formation increases. This study revealed that finding an optimum process parameter is important in achieving better properties in laser metal deposition of TiC/Ti6Al4V composite. The optimum process parameter was found to be at laser power of 1.8 kW and scanning speed of 0.05 m/s based on the process parameters considered in this study.
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- Authors: Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo
- Date: 2016
- Subjects: Intermetallic , Laser metal deposition , Processing parameters
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/214836 , uj:21332 , Citation: Mohamood, R.M & Akinlabi, E.T. 2016. Laser power and scanning speed influence on intermetallic and wear behaviour of laser metal deposited titanium alloy composite.
- Description: Abstract: Ti6Al4V, an aerospace alloy, is the most widely produced titanium alloy because of its exciting properties such as high strength to weight ratio and excellent corrosion resistance properties. Despite these properties of this titanium alloy, the wear property is poor because of its chemical property that makes it react with other material it comes in contact with. Therefore, there is need for surface modification of the titanium alloy if it will be used in application where it will come in contact will other material in rubbing or sliding action. TiC has been used to improve the wear resistance property of titanium alloy with success. Laser metal deposition (LMD) process, an additive manufacturing process, is an advanced manufacturing process for achieving part with the desired surface property as well as for producing complex part directly from the three dimensional (3D) computer aided design (CAD) model of the part. Processing parameter has a great influence on the resulting properties of the deposited part using LMD. This research investigates the influence of laser power and scanning speed on the in-situ formation of titanium aluminide (Ti3Al) during laser metal deposition of TiC/Ti6Al4V composite and its overall effect on the wear resistance behaviour of the deposited composites. The laser power was changed between 1.8 and 3.0 kW and the scanning speed was changed between 0.05 and 0.1 m/s. It was found that, the intermetallic produced increased as the scanning speed was reduced from 0.1 to 0.05 m/s. The intermetallic formed at low scanning speed was found to decrease as the laser power was increased from 1.8 to 3.0 kW, while it was found to increase as the laser power was increased at higher scanning speed. The wear resistance property increases as the intermetallic formation increases. This study revealed that finding an optimum process parameter is important in achieving better properties in laser metal deposition of TiC/Ti6Al4V composite. The optimum process parameter was found to be at laser power of 1.8 kW and scanning speed of 0.05 m/s based on the process parameters considered in this study.
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Laser metal deposition of functionally graded Ti6Al4V/TiC
- Mahamood, R. M., Akinlabi, Esther Titilayo
- Authors: Mahamood, R. M. , Akinlabi, Esther Titilayo
- Date: 2015-06-20
- Subjects: Functionally graded materials , Laser metal deposition , Titanium alloys
- Type: Article
- Identifier: uj:5119 , ISSN 02641275 , http://hdl.handle.net/10210/14077
- Description: Functionally graded materials (FGMs) are advanced materials with improved properties that enable them to withstand severe working environment which the traditional composite materials cannot withstand. FGM found their applications in several areas which include: military,medicine and aerospace. Various manufacturing processes are used to produce functionally graded materials that include: powder metallurgy, physical vapour deposition, chemical vapour deposition process and laser metal deposition process. Laser metal deposition (LMD) process is an additive manufacturing process that can be used to produce functionally graded material directly from the three dimensional (3D) computer aided design (CAD) model of the part in one single process. LMD process is a fairly new manufacturing process and a highly non-linear process. The process parameters are of great importance in LMD process and they need to be optimized for the required application. In this study, functionally graded titanium alloy composite was produced using optimized process parameters for each material combination as obtained through a model that was developed in an initial study and the FGM was characterized throughmetallurgical, mechanical and tribological studies. The results showthat the produced FGM has improved properties when compared to those produced at constant processing parameters for all material combinations.
- Full Text: false
- Authors: Mahamood, R. M. , Akinlabi, Esther Titilayo
- Date: 2015-06-20
- Subjects: Functionally graded materials , Laser metal deposition , Titanium alloys
- Type: Article
- Identifier: uj:5119 , ISSN 02641275 , http://hdl.handle.net/10210/14077
- Description: Functionally graded materials (FGMs) are advanced materials with improved properties that enable them to withstand severe working environment which the traditional composite materials cannot withstand. FGM found their applications in several areas which include: military,medicine and aerospace. Various manufacturing processes are used to produce functionally graded materials that include: powder metallurgy, physical vapour deposition, chemical vapour deposition process and laser metal deposition process. Laser metal deposition (LMD) process is an additive manufacturing process that can be used to produce functionally graded material directly from the three dimensional (3D) computer aided design (CAD) model of the part in one single process. LMD process is a fairly new manufacturing process and a highly non-linear process. The process parameters are of great importance in LMD process and they need to be optimized for the required application. In this study, functionally graded titanium alloy composite was produced using optimized process parameters for each material combination as obtained through a model that was developed in an initial study and the FGM was characterized throughmetallurgical, mechanical and tribological studies. The results showthat the produced FGM has improved properties when compared to those produced at constant processing parameters for all material combinations.
- Full Text: false
Process parameter interaction effect on the evolving properties of laser metal deposited titanium for biomedical applications
- Nyoni, Ezekiel, Akinlabi, Esther Titilayo
- Authors: Nyoni, Ezekiel , Akinlabi, Esther Titilayo
- Date: 2016
- Subjects: Biocompatibility , Dilution , Laser metal deposition
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/216973 , uj:21580 , Citation: Nyoni, E & Akinlabi, E.T. 2016. Process parameter interaction effect on the evolving properties of laser metal deposited titanium for biomedical applications.
- Description: Abstract: The laser power interaction effects on the evolving properties of commercially pure titanium during laser metal deposition were analysed. The optimized processing parameters obtained for this research study were, spot size of 4 mm, powder flow rate of 2 g/min, gas flow rate of 2 l/min, and the scanning speed set at 0.002m/s. A total of seven samples were fabricated by depositing titanium powder onto a Ti-6Al-4V base metal; using an Nd-Yag laser by varying the laser power from 400 to 1600 watts while keeping all the other parameters constant. The deposited samples were characterised through the evolving microstructure, microhardness, wear and the corrosion behaviour. The microstructural evaluation revealed that the ratio of dilution increased with an increase in the laser power. Furthermore, it was found that as the dilution increased, the wear resistance behaviour of the deposits decreased due to the increased foreign elements (Al and V) from the substrate which inhibited smooth fusion as the molten deposit cooled...
- Full Text:
- Authors: Nyoni, Ezekiel , Akinlabi, Esther Titilayo
- Date: 2016
- Subjects: Biocompatibility , Dilution , Laser metal deposition
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/216973 , uj:21580 , Citation: Nyoni, E & Akinlabi, E.T. 2016. Process parameter interaction effect on the evolving properties of laser metal deposited titanium for biomedical applications.
- Description: Abstract: The laser power interaction effects on the evolving properties of commercially pure titanium during laser metal deposition were analysed. The optimized processing parameters obtained for this research study were, spot size of 4 mm, powder flow rate of 2 g/min, gas flow rate of 2 l/min, and the scanning speed set at 0.002m/s. A total of seven samples were fabricated by depositing titanium powder onto a Ti-6Al-4V base metal; using an Nd-Yag laser by varying the laser power from 400 to 1600 watts while keeping all the other parameters constant. The deposited samples were characterised through the evolving microstructure, microhardness, wear and the corrosion behaviour. The microstructural evaluation revealed that the ratio of dilution increased with an increase in the laser power. Furthermore, it was found that as the dilution increased, the wear resistance behaviour of the deposits decreased due to the increased foreign elements (Al and V) from the substrate which inhibited smooth fusion as the molten deposit cooled...
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Influence of laser scanning speed on the rotary wear behaviour of deposited Ti6Al4V alloy and Cu
- Erinosho, Mutiu F., Akinlabi, Esther Titilayo, Mubiayi, Mukuna P., Owolabi, Gbadebo
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Mubiayi, Mukuna P. , Owolabi, Gbadebo
- Date: 2017
- Subjects: Cu , Laser metal deposition , Wear measurement
- Language: English
- Type: Conference proceedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/371820 , http://hdl.handle.net/10210/251731 , uj:26224 , Citation: Erinosho, M.F., Akinlabi, E.T., Mubiayi, M.P. & Owolabi, G. 2017. Influence of laser scanning speed on the rotary wear behaviour of deposited Ti6Al4V alloy and Cu.
- Description: Abstract: Laser metal deposition (LMD) is an additive manufacturing technology that involves the combination of metallic powder and laser beam for its consolidation. The process parameters involved in LMD need to be well understood and implemented correctly before the optimal process can be achieved. This paper reports the effect of scanning speed on the wear behaviour of laser deposited samples. The rotary wear method was adopted in order to understand the relationship in the radii of the wear track. The scanning speeds were varied from 0.0083 m/sec to 0.0333 m/sec while the laser power of 1.0 kW, the powder flow rate of 1 rpm and the gas flow rate of 2 l/min were kept constant. Some lateral cracks were observed in the microstructure which was due to the effect of the thermal stress that was induced during cooling. The laser deposited samples are suitable for repair in marine industry as the manufacturing process will provide a great control to the desired material properties with superior performance.
- Full Text:
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Mubiayi, Mukuna P. , Owolabi, Gbadebo
- Date: 2017
- Subjects: Cu , Laser metal deposition , Wear measurement
- Language: English
- Type: Conference proceedings
- Identifier: http://ujcontent.uj.ac.za8080/10210/371820 , http://hdl.handle.net/10210/251731 , uj:26224 , Citation: Erinosho, M.F., Akinlabi, E.T., Mubiayi, M.P. & Owolabi, G. 2017. Influence of laser scanning speed on the rotary wear behaviour of deposited Ti6Al4V alloy and Cu.
- Description: Abstract: Laser metal deposition (LMD) is an additive manufacturing technology that involves the combination of metallic powder and laser beam for its consolidation. The process parameters involved in LMD need to be well understood and implemented correctly before the optimal process can be achieved. This paper reports the effect of scanning speed on the wear behaviour of laser deposited samples. The rotary wear method was adopted in order to understand the relationship in the radii of the wear track. The scanning speeds were varied from 0.0083 m/sec to 0.0333 m/sec while the laser power of 1.0 kW, the powder flow rate of 1 rpm and the gas flow rate of 2 l/min were kept constant. Some lateral cracks were observed in the microstructure which was due to the effect of the thermal stress that was induced during cooling. The laser deposited samples are suitable for repair in marine industry as the manufacturing process will provide a great control to the desired material properties with superior performance.
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Laser metal deposition of Ti6Al4V/Cu composite : a study of the effect of laser power on the evolving properties
- Erinosho, Mutiu F., Akinlabi, Esther Titilayo, Pityana, Sisa
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2014
- Subjects: Porosity , Laser metal deposition , Titanium alloys
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/375937 , uj:4740 , ISSN 978-93-81505-62-5 , http://hdl.handle.net/10210/11726
- Description: A study of the effect of laser power was investigated over the volume of deposited composite, microstructure and microhardness. The laser power was varied between 600 and 1800 W while keeping all other parameters constant. An indication shows that the area and the volume of the deposited composites are directly proportional to the laser power employed. The volume of the deposit obtained falls between 358.6 mm3 and 1009 mm3. The microstructures were analyzed and found that the formation of the Widmanstatten structures improved the hardness of Ti6Al4V/Cu composites. The hardness values of the deposits varied between HV335 and HV490. The percentages of porosities of the samples were also presented and found to have an inverse relationship with the laser power. The results are presented and discussed.
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- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2014
- Subjects: Porosity , Laser metal deposition , Titanium alloys
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/375937 , uj:4740 , ISSN 978-93-81505-62-5 , http://hdl.handle.net/10210/11726
- Description: A study of the effect of laser power was investigated over the volume of deposited composite, microstructure and microhardness. The laser power was varied between 600 and 1800 W while keeping all other parameters constant. An indication shows that the area and the volume of the deposited composites are directly proportional to the laser power employed. The volume of the deposit obtained falls between 358.6 mm3 and 1009 mm3. The microstructures were analyzed and found that the formation of the Widmanstatten structures improved the hardness of Ti6Al4V/Cu composites. The hardness values of the deposits varied between HV335 and HV490. The percentages of porosities of the samples were also presented and found to have an inverse relationship with the laser power. The results are presented and discussed.
- Full Text:
Microstructures and dry sliding wear characteristics of the laser metal deposited Ti6Al4V/Cu composites
- Erinosho, Mutiu F., Akinlabi, Esther Titilayo, Pityana, Sisa
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2015
- Subjects: Dry sliding wear , Laser metal deposition , Microstructures , Titanium composites , Copper composites
- Type: Article
- Identifier: uj:5139 , http://hdl.handle.net/10210/14106
- Description: This paper reports on the investigations conducted on the evolving microstructures and the dry sliding wear of the laser deposited Ti6Al4V/Cu composites. Some selected process parameters were used for the experiments. The laser powers were chosen between 1300 W and 1600 W; scanning speeds were selected between 0.30 m/min and 0.72 m/min while other parameters are as specified in the experimental matrix. It was found that all the composites produced showed good and high-quality microstructures and they exhibited very low or no fusion zones which were as a result of the selected process parameters used. The composite produced at a laser power of 1397 W and a scanning speed of 0.3 m/min was found to show the lowest percentage of wear volume and coefficient of friction; and happened due to the martensitic structure formed during cooling. Results obtained showed that the poor abrasive wear of titanium alloy has been improved with the addition of copper into their lattices.
- Full Text:
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2015
- Subjects: Dry sliding wear , Laser metal deposition , Microstructures , Titanium composites , Copper composites
- Type: Article
- Identifier: uj:5139 , http://hdl.handle.net/10210/14106
- Description: This paper reports on the investigations conducted on the evolving microstructures and the dry sliding wear of the laser deposited Ti6Al4V/Cu composites. Some selected process parameters were used for the experiments. The laser powers were chosen between 1300 W and 1600 W; scanning speeds were selected between 0.30 m/min and 0.72 m/min while other parameters are as specified in the experimental matrix. It was found that all the composites produced showed good and high-quality microstructures and they exhibited very low or no fusion zones which were as a result of the selected process parameters used. The composite produced at a laser power of 1397 W and a scanning speed of 0.3 m/min was found to show the lowest percentage of wear volume and coefficient of friction; and happened due to the martensitic structure formed during cooling. Results obtained showed that the poor abrasive wear of titanium alloy has been improved with the addition of copper into their lattices.
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Gas flow rate and powder flow rate effect on properties of laser metal deposited Ti6Al4V
- Pityana, Sisa, Mahamood, Rasheedat M., Akinlabi, Esther Titilayo, Shukla, Mukul
- Authors: Pityana, Sisa , Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo , Shukla, Mukul
- Date: 2013
- Subjects: Gas flow rate , Microhardness , Microstructure , Powder flow rate , Laser metal deposition , Additive manufacturing technology
- Type: Article
- Identifier: uj:4849 , http://hdl.handle.net/10210/12516
- Description: Tracks of Ti6Al4V powder were deposited on Ti6Al4V substrate using Laser Metal Deposition (LMD) process, an Additive Manufacturing (AM) manufacturing technology, at a laser power and scanning speed maintained at 1.8 kW and 0.005 m/s respectively. The powder flow rate and the gas flow rate were varied to study their effect on the physical, metallurgical and mechanical properties of the deposits. The physical properties studied are: the track width, the track height and the deposit weight. The mechanical property studied is the Microhardness profiling using Microhardness indenter at a load of 500g and dwelling time of 15 μm. The metallurgical property studied is the microstructure using the Optical microscopy. This study revealed that as the powder flow rate was increased, the track width, track height and the deposit weight were increased while as the powder flow rate was increased, the track width, track height and the deposit weight decreased. The results are presented and discussed in detail.
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- Authors: Pityana, Sisa , Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo , Shukla, Mukul
- Date: 2013
- Subjects: Gas flow rate , Microhardness , Microstructure , Powder flow rate , Laser metal deposition , Additive manufacturing technology
- Type: Article
- Identifier: uj:4849 , http://hdl.handle.net/10210/12516
- Description: Tracks of Ti6Al4V powder were deposited on Ti6Al4V substrate using Laser Metal Deposition (LMD) process, an Additive Manufacturing (AM) manufacturing technology, at a laser power and scanning speed maintained at 1.8 kW and 0.005 m/s respectively. The powder flow rate and the gas flow rate were varied to study their effect on the physical, metallurgical and mechanical properties of the deposits. The physical properties studied are: the track width, the track height and the deposit weight. The mechanical property studied is the Microhardness profiling using Microhardness indenter at a load of 500g and dwelling time of 15 μm. The metallurgical property studied is the microstructure using the Optical microscopy. This study revealed that as the powder flow rate was increased, the track width, track height and the deposit weight were increased while as the powder flow rate was increased, the track width, track height and the deposit weight decreased. The results are presented and discussed in detail.
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Effect of powder density variation on premixed Ti-6Al-4V and Cu composites during laser metal deposition
- Erinosho, Mutiu F., Akinlabi, Esther Titilayo, Pityana, Sisa
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2016
- Subjects: Powder density , Laser metal deposition , Titanium alloys , Copper
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/123406 , uj:20787 , Citation: Erinosho, M.F., Akinlabi, E.T & Pityana, S. 2016. Effect of powder density variation on premixed Ti-6Al-4V and Cu composites during laser metal deposition.
- Description: Abstract: This paper reports the effect of powder density variation on the premixed Ti-6Al-4V/Cu and Ti-6Al-4V/2Cu Composites. Two sets of experiment were conducted in this study. Five deposits each were made for the two premixed composites. Laser powers were varied between 600 W and 1700 W while a scanning speed of 0.3 m/min is kept constant throughout the experiment. Investigations were conducted on the microstructures and microhardness of the laser deposited premixed Ti-6Al-4V/Cu and Ti-6Al-4V/2Cu composites. It was found that the evolving microstructures of the composites were characterised with the formation of macroscopic banding and Widmanstatten; and disappears as it grows towards the fusion zone (FZ) and this could be attributed to the changes in the distribution of heat input. Sample A2 of premixed Ti-6Al-4V/Cu composite gives the highest hardness of 393 ± 6.36VHN0.5 while sample B4 of premixed Ti-6Al-4V/2Cu composites depicts the highest hardness value of 373 ± 9.18VHN0.5.
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- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2016
- Subjects: Powder density , Laser metal deposition , Titanium alloys , Copper
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/123406 , uj:20787 , Citation: Erinosho, M.F., Akinlabi, E.T & Pityana, S. 2016. Effect of powder density variation on premixed Ti-6Al-4V and Cu composites during laser metal deposition.
- Description: Abstract: This paper reports the effect of powder density variation on the premixed Ti-6Al-4V/Cu and Ti-6Al-4V/2Cu Composites. Two sets of experiment were conducted in this study. Five deposits each were made for the two premixed composites. Laser powers were varied between 600 W and 1700 W while a scanning speed of 0.3 m/min is kept constant throughout the experiment. Investigations were conducted on the microstructures and microhardness of the laser deposited premixed Ti-6Al-4V/Cu and Ti-6Al-4V/2Cu composites. It was found that the evolving microstructures of the composites were characterised with the formation of macroscopic banding and Widmanstatten; and disappears as it grows towards the fusion zone (FZ) and this could be attributed to the changes in the distribution of heat input. Sample A2 of premixed Ti-6Al-4V/Cu composite gives the highest hardness of 393 ± 6.36VHN0.5 while sample B4 of premixed Ti-6Al-4V/2Cu composites depicts the highest hardness value of 373 ± 9.18VHN0.5.
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Characterising the effect of laser metal deposited Ti6Al4V/Cu composites in simulated body fluid for biomedical application
- Erinosho, M. F., Akinlabi, Esther Titilayo, Pityana, S.
- Authors: Erinosho, M. F. , Akinlabi, Esther Titilayo , Pityana, S.
- Date: 2015-01-15
- Subjects: Hank’s solution , Laser metal deposition , Surface morphologies , Titanium alloys
- Type: Article
- Identifier: uj:5120 , ISBN 9789384935108 , http://hdl.handle.net/10210/14078
- Description: Ti6Al4V alloy has been known to have very excellent corrosion resistance due to the oxide layer formed on its surface. Due to this property, the alloy is found applicable for biomedical implants. Copper shows an excellent antimicrobial property and has been found to stabilize the immune system. In this study, laser metal deposition of Ti6Al4V powder and Cu powder on Ti6Al4V substrates were conducted by varying the laser power between 600 W and 1800 W while the scanning speed, the powder flow rate and the gas flow rate were kept constant. The surface behaviour and the morphologies of the composites were evaluated under the microscope and the SEM after soaking for 4 hours, 5 days and 2 weeks respectively. The simulated body fluid (hank’s solution) was maintained at normal body temperature of about 37±1oC. The surfaces showed fracture topography with porous bone-like structures and some trivial pitting were observed.
- Full Text:
- Authors: Erinosho, M. F. , Akinlabi, Esther Titilayo , Pityana, S.
- Date: 2015-01-15
- Subjects: Hank’s solution , Laser metal deposition , Surface morphologies , Titanium alloys
- Type: Article
- Identifier: uj:5120 , ISBN 9789384935108 , http://hdl.handle.net/10210/14078
- Description: Ti6Al4V alloy has been known to have very excellent corrosion resistance due to the oxide layer formed on its surface. Due to this property, the alloy is found applicable for biomedical implants. Copper shows an excellent antimicrobial property and has been found to stabilize the immune system. In this study, laser metal deposition of Ti6Al4V powder and Cu powder on Ti6Al4V substrates were conducted by varying the laser power between 600 W and 1800 W while the scanning speed, the powder flow rate and the gas flow rate were kept constant. The surface behaviour and the morphologies of the composites were evaluated under the microscope and the SEM after soaking for 4 hours, 5 days and 2 weeks respectively. The simulated body fluid (hank’s solution) was maintained at normal body temperature of about 37±1oC. The surfaces showed fracture topography with porous bone-like structures and some trivial pitting were observed.
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Effect of scanning speed on laser deposited 17-4PH stainless Steel
- Bayode, Abiodun, Pityana, Sisa, Akinlabi, Esther Titilayo, Shongwe, Mxolisi Brendon
- Authors: Bayode, Abiodun , Pityana, Sisa , Akinlabi, Esther Titilayo , Shongwe, Mxolisi Brendon
- Date: 2017
- Subjects: Functionaly graded material , Laser metal deposition , Mechanical property
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237432 , uj:24324 , Citation: Bayode, A. et al. 2017. Effect of scanning speed on laser deposited 17-4PH stainless Steel.
- Description: Abstract: Laser metal deposition (LMD) is one of the additive manufacturing technologies that is used in the production of fully dense parts layer by layer. This innovative manufacturing process has the potential to reduce the weight, time and cost of manufacturing components. It is able to process different metallic powders and also produce custom alloy or functionally graded material by consolidating different metallic powders. The purpose of this study was to investigate and discuss the structural integrity, mechanical property and microstructure of 17-4 precipitation hardened stainless steel processed by laser metal deposition. In this study, the laser scanning speed was varied while other process parameters where kept constant. Material characterization was done using optical microscopy and Vickers indentation testing. The results show that, the processed material was structurally sound and defect free. The microstructure was predominantly martensitic and the laser scanning speed was observed to have an influence on the micro-hardness of the structure.
- Full Text:
- Authors: Bayode, Abiodun , Pityana, Sisa , Akinlabi, Esther Titilayo , Shongwe, Mxolisi Brendon
- Date: 2017
- Subjects: Functionaly graded material , Laser metal deposition , Mechanical property
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237432 , uj:24324 , Citation: Bayode, A. et al. 2017. Effect of scanning speed on laser deposited 17-4PH stainless Steel.
- Description: Abstract: Laser metal deposition (LMD) is one of the additive manufacturing technologies that is used in the production of fully dense parts layer by layer. This innovative manufacturing process has the potential to reduce the weight, time and cost of manufacturing components. It is able to process different metallic powders and also produce custom alloy or functionally graded material by consolidating different metallic powders. The purpose of this study was to investigate and discuss the structural integrity, mechanical property and microstructure of 17-4 precipitation hardened stainless steel processed by laser metal deposition. In this study, the laser scanning speed was varied while other process parameters where kept constant. Material characterization was done using optical microscopy and Vickers indentation testing. The results show that, the processed material was structurally sound and defect free. The microstructure was predominantly martensitic and the laser scanning speed was observed to have an influence on the micro-hardness of the structure.
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Influence of laser power on the surfacing microstructures and microhardness properties of Ti-6Al-4V-Cu alloys using the ytterbium fiber laser
- Erinosho, Mutiu F., Akinlabi, Esther Titilayo
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo
- Date: 2017
- Subjects: Laser metal deposition , Microhardness , Microstructures
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/233106 , uj:23793 , Citation: Erinosho, M.F. & Akinlabi, E.T. 2017. Influence of laser power on the surfacing microstructures and microhardness properties of Ti-6Al-4V-Cu alloys using the ytterbium fiber laser. 5th International Conference of Materials Processing and Characterization (ICMPC 2016).
- Description: Abstract: Laser Metal Deposition (LMD) is a route that involves the spraying of metallic powders onto a substrate with the application of beam of light. The deposition of titanium alloy (Ti-6Al-4V) with five weight percent (5 wt %) of copper (Cu) has been explored and characterized through the developing microstructures and microhardness. A constant scanning speed of 0.3 m/min and laser powers varied between 400 W and 1600 W were used for the process parameters. The Widmanstatten structures were even at low laser powers and later increased in their coarseness and propagate further as the laser power increases; and the occurrence can be attributed to the further increase in the heat input from the top of the clad to the substrate and the slow cooling rate within the cladded zone of the composites. A typical sample D4 deposited with a laser power of 1000 W exhibits the highest hardness value of 541 ± 88 HV0.5 while sample D2 deposited at a laser power of 600 W depicts the lowest hardness value of 448 ± 58 HV0.5. The properties of the Ti-6Al-4V-Cu alloys have been improved and can be recommended for marine application.
- Full Text:
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo
- Date: 2017
- Subjects: Laser metal deposition , Microhardness , Microstructures
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/233106 , uj:23793 , Citation: Erinosho, M.F. & Akinlabi, E.T. 2017. Influence of laser power on the surfacing microstructures and microhardness properties of Ti-6Al-4V-Cu alloys using the ytterbium fiber laser. 5th International Conference of Materials Processing and Characterization (ICMPC 2016).
- Description: Abstract: Laser Metal Deposition (LMD) is a route that involves the spraying of metallic powders onto a substrate with the application of beam of light. The deposition of titanium alloy (Ti-6Al-4V) with five weight percent (5 wt %) of copper (Cu) has been explored and characterized through the developing microstructures and microhardness. A constant scanning speed of 0.3 m/min and laser powers varied between 400 W and 1600 W were used for the process parameters. The Widmanstatten structures were even at low laser powers and later increased in their coarseness and propagate further as the laser power increases; and the occurrence can be attributed to the further increase in the heat input from the top of the clad to the substrate and the slow cooling rate within the cladded zone of the composites. A typical sample D4 deposited with a laser power of 1000 W exhibits the highest hardness value of 541 ± 88 HV0.5 while sample D2 deposited at a laser power of 600 W depicts the lowest hardness value of 448 ± 58 HV0.5. The properties of the Ti-6Al-4V-Cu alloys have been improved and can be recommended for marine application.
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Laser surface modification of Ti6Al4V-Cu for improved microhardness and wear resistance properties
- Erinosho, Mutiu F, Akinlabi, Esther Titilayo, Pityana, Sisa, Owolabi, Gbadebo
- Authors: Erinosho, Mutiu F , Akinlabi, Esther Titilayo , Pityana, Sisa , Owolabi, Gbadebo
- Date: 2017
- Subjects: Dry sliding wear , Laser metal deposition , Microstructure
- Language: English
- Type: Articles
- Identifier: http://hdl.handle.net/10210/241797 , uj:24925 , Citation: Erinosho, M.F. et al. 2017. Laser surface modification of Ti6Al4V-Cu for improved microhardness and wear resistance properties.
- Description: Abstract: The light weight of Ti6Al4V as a titanium alloy is been amongst the properties that have been tailed for the aerospace and other industrial applications. To modify the properties of this alloy, Cu has been added to host an antimicrobial effect in the revised alloy for marine application. The LMD process on the Ti6Al4V alloy and Cu was been investigated for surface modification in order to combat the problem of biofouling in the marine industry. The investigations focused on the microstructural observations, micro-hardness measurements and dry sliding wear in the presence of 3 and 5 weight percents of Cu. The microstructure results showed that Widmanstätten microstructures were formed in all the samples and lose their robustness towards the fusion zone as a result of the transition of heat sink towards the substrate. The microhardness values of Ti6Al4V-3Cu and Ti6Al4V-5Cu alloys were greatly improved to 547±16 VHN0.5 and 519±54 VHN0.5 respectively. In addition, the behaviour of wear loss on the surface of the Ti6Al4V-Cu alloys exhibited great improvement as compared with the parent...
- Full Text:
- Authors: Erinosho, Mutiu F , Akinlabi, Esther Titilayo , Pityana, Sisa , Owolabi, Gbadebo
- Date: 2017
- Subjects: Dry sliding wear , Laser metal deposition , Microstructure
- Language: English
- Type: Articles
- Identifier: http://hdl.handle.net/10210/241797 , uj:24925 , Citation: Erinosho, M.F. et al. 2017. Laser surface modification of Ti6Al4V-Cu for improved microhardness and wear resistance properties.
- Description: Abstract: The light weight of Ti6Al4V as a titanium alloy is been amongst the properties that have been tailed for the aerospace and other industrial applications. To modify the properties of this alloy, Cu has been added to host an antimicrobial effect in the revised alloy for marine application. The LMD process on the Ti6Al4V alloy and Cu was been investigated for surface modification in order to combat the problem of biofouling in the marine industry. The investigations focused on the microstructural observations, micro-hardness measurements and dry sliding wear in the presence of 3 and 5 weight percents of Cu. The microstructure results showed that Widmanstätten microstructures were formed in all the samples and lose their robustness towards the fusion zone as a result of the transition of heat sink towards the substrate. The microhardness values of Ti6Al4V-3Cu and Ti6Al4V-5Cu alloys were greatly improved to 547±16 VHN0.5 and 519±54 VHN0.5 respectively. In addition, the behaviour of wear loss on the surface of the Ti6Al4V-Cu alloys exhibited great improvement as compared with the parent...
- Full Text:
Experimental and numerical analysis of geometrical properties of laser metal deposited titanium
- Akinlabi, Esther Titilayo, Tayob, Mohammed A., Pietra, Francesco
- Authors: Akinlabi, Esther Titilayo , Tayob, Mohammed A. , Pietra, Francesco
- Date: 2016
- Subjects: Ansys , Heat-Affected zone , Laser metal deposition , Microhardness , Microstructure , Porosity , Powder flow rate , Titanium
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93300 , uj:20330 , Citation: Akinlabi, E.T., Tayob, M.A. & Pietra, F. 2016. Experimental and numerical analysis of geometrical properties of laser metal deposited titanium.
- Description: Abstract: Laser metal deposition (LMD) is a manufacturing process, which can be used to manufacture a complete, fully functional part by building it up layer-by-layer using the data from a Computer-Aided-Design (CAD) file. The layer-by-layer addition can also be used to rebuild worn-out sections of existing parts, as well as to deposit protective coatings to protect parts in surface engineering. The process involves laser heating a substrate, on which a metal powder is deposited. The powder solidifies, when mixed with the substrate, thereby creating a metallurgical bond. In order to produce parts with high geometrical tolerances and desirable material properties, the process parameters have to be carefully controlled. Since the LMD process requires the interaction of parameters, it is not always easy to predict the output geometry. In this paper, the laser metal deposition process was modelled in ANSYS Parametric- Design-Language (APDL), using a transient thermal analysis, in order to determine the geometrical properties of the clad, that is, the width and the height of the resulting clad. The simulated results were then compared experimentally by depositing Commercially Pure (CP) titanium powder onto a Ti-6Al-4V substrate, in order to verify the simulation. The varying parameter in the experimental process was the powder flow rate, which was varied between 0.5-2.5g/min. In addition to the geometrical properties, the microstructure, microhardness; and the porosity levels of the deposited clads were also analyzed, in order to better determine the clad quality and integrity. The model showed good agreement in predicting both the height and the width of the clads. Porosity was noticed in all the samples with the exception of the clad deposited at the lowest powder flow rate setting of 0.5 g/min. An increase in the powder flow rate also led to a smaller fusion zone, due to a lower laser-material interaction period, which was the result of the increase in the quantity of powder causing attenuation of the beam, and less laser power being absorbed by the substrate. The smaller fusion zone meant that the clads could not bond to the substrate properly, which led to the clad in the sample produced with the highest powder flow rate falling off the substrate. There was a significant increase in the microhardness of the clad zone, which was due to a combination of alloying with Ti- 6Al-4V and a change in the microstructure to an acicular alpha martensite microstructure; while the Heat-Affected-Zone (HAZ) in the substrate only showed a slight increase in microhardness.
- Full Text:
- Authors: Akinlabi, Esther Titilayo , Tayob, Mohammed A. , Pietra, Francesco
- Date: 2016
- Subjects: Ansys , Heat-Affected zone , Laser metal deposition , Microhardness , Microstructure , Porosity , Powder flow rate , Titanium
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93300 , uj:20330 , Citation: Akinlabi, E.T., Tayob, M.A. & Pietra, F. 2016. Experimental and numerical analysis of geometrical properties of laser metal deposited titanium.
- Description: Abstract: Laser metal deposition (LMD) is a manufacturing process, which can be used to manufacture a complete, fully functional part by building it up layer-by-layer using the data from a Computer-Aided-Design (CAD) file. The layer-by-layer addition can also be used to rebuild worn-out sections of existing parts, as well as to deposit protective coatings to protect parts in surface engineering. The process involves laser heating a substrate, on which a metal powder is deposited. The powder solidifies, when mixed with the substrate, thereby creating a metallurgical bond. In order to produce parts with high geometrical tolerances and desirable material properties, the process parameters have to be carefully controlled. Since the LMD process requires the interaction of parameters, it is not always easy to predict the output geometry. In this paper, the laser metal deposition process was modelled in ANSYS Parametric- Design-Language (APDL), using a transient thermal analysis, in order to determine the geometrical properties of the clad, that is, the width and the height of the resulting clad. The simulated results were then compared experimentally by depositing Commercially Pure (CP) titanium powder onto a Ti-6Al-4V substrate, in order to verify the simulation. The varying parameter in the experimental process was the powder flow rate, which was varied between 0.5-2.5g/min. In addition to the geometrical properties, the microstructure, microhardness; and the porosity levels of the deposited clads were also analyzed, in order to better determine the clad quality and integrity. The model showed good agreement in predicting both the height and the width of the clads. Porosity was noticed in all the samples with the exception of the clad deposited at the lowest powder flow rate setting of 0.5 g/min. An increase in the powder flow rate also led to a smaller fusion zone, due to a lower laser-material interaction period, which was the result of the increase in the quantity of powder causing attenuation of the beam, and less laser power being absorbed by the substrate. The smaller fusion zone meant that the clads could not bond to the substrate properly, which led to the clad in the sample produced with the highest powder flow rate falling off the substrate. There was a significant increase in the microhardness of the clad zone, which was due to a combination of alloying with Ti- 6Al-4V and a change in the microstructure to an acicular alpha martensite microstructure; while the Heat-Affected-Zone (HAZ) in the substrate only showed a slight increase in microhardness.
- Full Text:
Behaviour of laser metal deposited Ti6Al4V/Cu composites in hank’s solution for biocompatibility properties
- Erinosho, Mutiu F., Akinlabi, Esther Titilayo, Pityana, Sisa
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2016
- Subjects: Hank’s solution , Laser metal deposition , Microhardness
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/215427 , uj:21416 , Citation: Erinosho, M.F., Akinlabi, E.T & Pityana, S. 2016. Behaviour of laser metal deposited Ti6Al4V/Cu composites in hank’s solution for biocompatibility properties.
- Description: Abstract: Ti6Al4V alloy is a well-known material for biomedical application due to the very excellent corrosion resistance it possessed. Copper is an excellent antimicrobial property and has been found to stabilize the immune system of the body activities. In this present study, laser metal deposition of Ti6Al4V/Cu composites have been conducted by varying the laser power between 600 W and 1800 W while the scanning speed of 0.005 m/s and other process parameters as depicted in the experimental matrix were kept constant. Widmanstettan structures were observed in all the samples at high magnification and lose their coarseness as the laser power increases. The microhardness values of the deposited composites were varied between HV335 ± 27 μm and HV490 ± 73 μm. The surface behaviour and the morphologies of the composites were evaluated under the SEM after soaking for 2 weeks. The simulated body fluid (hank’s solution) was maintained at normal body temperature of about 37±1oC. The surfaces showed fracture topography with porous bone-like and snowflake structures.
- Full Text:
- Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
- Date: 2016
- Subjects: Hank’s solution , Laser metal deposition , Microhardness
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/215427 , uj:21416 , Citation: Erinosho, M.F., Akinlabi, E.T & Pityana, S. 2016. Behaviour of laser metal deposited Ti6Al4V/Cu composites in hank’s solution for biocompatibility properties.
- Description: Abstract: Ti6Al4V alloy is a well-known material for biomedical application due to the very excellent corrosion resistance it possessed. Copper is an excellent antimicrobial property and has been found to stabilize the immune system of the body activities. In this present study, laser metal deposition of Ti6Al4V/Cu composites have been conducted by varying the laser power between 600 W and 1800 W while the scanning speed of 0.005 m/s and other process parameters as depicted in the experimental matrix were kept constant. Widmanstettan structures were observed in all the samples at high magnification and lose their coarseness as the laser power increases. The microhardness values of the deposited composites were varied between HV335 ± 27 μm and HV490 ± 73 μm. The surface behaviour and the morphologies of the composites were evaluated under the SEM after soaking for 2 weeks. The simulated body fluid (hank’s solution) was maintained at normal body temperature of about 37±1oC. The surfaces showed fracture topography with porous bone-like and snowflake structures.
- Full Text: