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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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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

Non-destructive residual stress analysis and microstructural behaviour of laser deposited titanium and copper alloy

- Erinosho, Mutiu F., Akinlabi, Esther Titilayo

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

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

Microstructure and microhardness of 17-4 ph stainless steel made by laser metal deposition

- Bayode, A., Akinlabi, Esther Titilayo, Pityana, S.

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...
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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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Laser metal deposition of titanium aluminide composites : a review

- Abdulrahman, Kamardeen O., Akinlabi, Esther Titilayo, Mahamood, Rasheedat M., Pityana, Sisa, Tlotleng, Monnamme

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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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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Influence of scanning speed and energy density on the evolving properties of laser deposited Ti6Al4V/Cu composites

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

  • Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
  • Date: 2015-07-01
  • Subjects: Laser metal deposition , Microhardness , Titanium composites , Copper composites
  • Type: Article
  • Identifier: uj:5131 , ISBN 9789881404701 , http://hdl.handle.net/10210/14094
  • Description: Titanium is a light metal and finds application majorly in the aerospace and bio medicals. This paper presents the influence of scanning speed and energy density on the evolving microstructure and microhardness of laser deposited Ti6Al4V/Cu composites. The laser power, powder flow rates and gas flow rates were kept constant while varying the scanning speed. From the microscopic analysis, α acicular structures were found growing from the top of the cross section of the composite and broke into the β-phase and the grain boundary of the (α+β) phase, and found to disappear gradually as the scanning speed increases. Widmanstettan was also found in all the samples. Sample S21 of energy density 240 J/mm2 deposited with a laser power of 1200 W and a scanning speed of 5 mm/secs shows the highest hardness value of 541±20 HV0.5 while Sample S27 of energy density of 48 J/mm2 deposited with a laser power of 1200 W and a scanning speed of 25 mm/secs shows the lowest hardness value of 405±12 HV0.5. This was attributed to the Cu content added and plays a vital role in stabilizing and strengthening the β-phase.
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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

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

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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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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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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Exploration of microstructure and wear behaviours of laser metal deposited Ti6Al4V/Cu composites

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

  • Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
  • Date: 2016
  • Subjects: Dry sliding wear , Laser metal deposition , Microstructures
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/215408 , uj:21415 , Citation: Erinosho, M.F., Akinlabi, E.T & Pityana, S. 2016. Exploration of microstructure and wear behaviours of laser metal deposited Ti6Al4V/Cu composites.
  • Description: Abstract: 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 α-phase region of the composites was found to be harder than the β-phase region. During the composites cooling, the β-phase field transformed to the basal planes of the hexagonal α-phase thereby creating a lower diffusion coefficient of the α-phase as compared to the β-phase counterpart. The Ti6Al4V/Cu 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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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.
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