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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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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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Process parameter interaction effect on the evolving properties of laser metal deposited titanium for biomedical applications

- Nyoni, Ezekiel, Akinlabi, Esther Titilayo

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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Microstructure of Ti6Al4V reinforced by coating W particles through laser metal deposition

- Ndou, Ndivhuwo, Akinlabi, Esther Titilayo, Pityana, Sisa, Shongwe, Mxolisi

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

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

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

- Mahamood, R.M., Akinlabi, Esther Titilayo

  • Authors: Mahamood, R.M. , Akinlabi, Esther Titilayo
  • Date: 2018
  • Subjects: Corosion rate , Laser metal deposition , Laser Engineered Net shaping
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/290913 , uj:31589 , Citation: Mahamood, R.M. & Akinlabi, E.T. 2018. Corrosion behaviour of laser additive manufactured titanium alloy.
  • Description: Abstract: The influence of process parameter on corrosion behavior of the most widely used titanium alloy-Ti6Al4V, produced using laser metal deposition process was studied. The processing parameters: scanning velocity, the powder flow rate and gas flow rate were kept at constant values of 0,005m/s, 1.44 g/min and 4 l/min while the laser power was varied between 0.8 to 3.0 kW. Electrochemical corrosion test was conducted on each of the samples produced at each set of processing parameters. The corrosive media used is the solution of sodium chloride (NaCl) desolved in deionized water. The results of this study indicate that the as the laser power was increase, the corrosion behaviour was found to be improved. The better corrosion resistance performance of the additive manufacture part can be attributed to the higher cooling rate that is associated with this type of manufacturing process. This high cooling rate results in the higher hardness of the material which could also contribute to the improved corrosion resistance behaviour.
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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.
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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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Non-destructive residual stress analysis and microstructural behaviour of laser deposited titanium and copper alloy

- Erinosho, Mutiu F., Akinlabi, Esther Titilayo

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

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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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.
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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

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

Behaviour of laser metal deposited Ti6Al4V/Cu composites in hank’s solution for biocompatibility properties

- Erinosho, Mutiu F., Akinlabi, Esther Titilayo, Pityana, Sisa

Influence of laser power on improving the wear properties of laser deposited Ti-6Al-4V+B4C composite

- Erinosho, Mutiu F., Akinlabi, Esther Titilayo

  • Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo
  • Date: 2018
  • Subjects: Laser metal deposition , Microstructure , Wear measurement
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/273312 , uj:29114 , Citation: Erinosho, M.F. & Akinlabi, E.T. 2018. Influence of laser power on improving the wear properties of laser deposited Ti-6Al-4V+B4C composite.
  • Description: Abstract: Titanium and its alloys have possessed outstanding properties such as high specific strength, good oxidation and corrosion resistance; which have made them extensively suitable for use in the aeronautical, medical, automobile, marine and chemical industries. This paper presents the impact of laser power on the microstructure and the wear properties of titanium matrix Ti-6Al-4V+B4C composites. The laser powers were varied between 0.8 kW and 2.2 kW while keeping other contributing parameters constant. The microstructural effects were characterised with increasing α-Ti lamella and coarse Widmanstettan structures as the laser power was increased; alongside with the inclusion of 20 wt % of B4C. The mechanical action during wear test has created a loop shape with inner and outer radii on the surface of the laser deposited composites. The wear thickness, depth and COF were taken into cognisance; with sample C deposited at a laser power of 1.8 kW and scanning speed of 1 m/min having the lowest wear loss of 0.119 mm3. The substrate exhibited the shallowest wear depth and the reason is attributed the compressive nature of the material. The interlace of B4C in the titanium matrix has improved the properties the laser formed composites.
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Estimation of surface topography and wear loss of laser metal deposited Ti6Al4V and Cu

- Erinosho, Mutiu F., Akinlabi, Esther Titilayo

  • Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo
  • Date: 2016
  • Subjects: Laser metal deposition , Microstructure , Surface roughness topography
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/214314 , uj:21265 , Citation: Erinosho, M.F & Akinlabi, E.T. 2016. Estimation of surface topography and wear loss of laser metal deposited Ti6Al4V and Cu.
  • Description: Abstract: The atomic force microscopy (AFM) analysis is a process that involves the detailed analyses of the surface of a three dimensional sample piece. A good image is always generated on such a sample once the settings are implemented correctly. And as such, the amplitude set point played a vital role in achieving a better image. For surface engineering applications, a small proportion of Cu has been added to Ti6Al4V alloy and deposited using a 2kW Ytterbium Fibre Laser. This paper presents the evolving microstructures and the surface topographies of the laser deposited Ti6Al4V/Cu alloys. The formation and the output of the microstructure depend on the laser processing parameters employed. The α-Ti lamella formed was observed to gain coarseness with respect to the increase in the laser power. The migration of the β-phase has been impeded during solidification due to the low strain hardening effect posed by the α-Ti lamella thereby limiting the further dislocation of the β-phase within the crystal structure. A clear picture of the height, amplitude and the phase shift of the scanned sample were viewed before a capture can be made. A correlation between wear loss and surface roughness has been established among the laser deposited samples.
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