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Additive manufacturing : the future of manufacturing

  • Authors: Adekanye, Adefemi , Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo , Owolabi, Moses G.
  • Date: 2017
  • Subjects: Additive manufacturing , Fused deposition modelling , Laser metal deposition
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/248998 , uj:25901 , Citation: Adekanye, A. et al. 2017. Additive manufacturing : the future of manufacturing.
  • Description: Abstract: Additive manufacturing process is an advanced manufacturing method that is used to fabricate prototypes, tooling, as well as functional product. Additive manufacturing process can produce complex part as a single unit object that was not possible with the traditional manufacturing methods. There are different types of additive manufacturing technologies which include selective laser melting, laser metal deposition process, fused deposition modelling and electron beam melting. All these additive manufacturing technologies produce three dimensional (3D) objects by adding materials layer after layer. The 3D object is built directly from the 3D computer aided design (CAD) model of the object. Additive manufacturing is a very promising manufacturing method for the aerospace industry in particular because of its ability to reduce buyto- fly ratio. This technology is the technology of the future because it is going to change the way products are designed and manufactured. In this research, various additive manufacturing technologies are described in detail and some of the research works in this field are also presented. The future research directions are also highlighted.
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Advanced coating: laser metal deposition of aluminium powder on titanium substrate

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

Central composite design on volume of laser metal deposited Ti6Al4V and Cu

Characterising the effect of laser metal deposited Ti6Al4V/Cu composites in simulated body fluid for biomedical application

  • 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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Characterising the effect of laser power on laser metal deposited titanium alloy and boron carbide

  • Authors: Erinosho, M. F. , Akinlabi, Esther Titilayo
  • Date: 2017
  • Subjects: Ti6Al4V-B4C composites , Laser metal deposition , Microstructure
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/241349 , uj:24845 , Citation: Erinosho, M.F. & Akinlabi, E.T. 2017. Characterising the effect of laser power on laser metal deposited titanium alloy and boron carbide.
  • Description: Abstract: Titanium alloy has gained acceptance in the aerospace, marine, chemical and other related industries due to its excellent combination of mechanical and corrosion properties. In order to augment its properties, a hard ceramic, boron carbide has been laser cladded with it at varying laser powers between 0.8 kW and 2.4 kW. This paper presents the effect of laser power on the laser deposited Ti6Al4V-B4C composites through the evolving microstructures and microhardness. The microstructures of the composites exhibit the formation of α-Ti phase and β-Ti phase and were elongated towards the heat affected zone. These phases were terminated at the fusion zone and globular microstructures were found growing epi! taxially just immediately after the fusion zone. Good bondings were formed in all the deposited composites. Sample A1 deposited at a laser power of 0.8 kW and scanning speed of 1 m/min exhibits the highest hardness of HV 432±27 while sample A4 deposited at a laser power of 2.0 kW and scanning speed of 1 m/min displays the lowest hardness of HV 360±18. From the hardness results obtained, ceramic B4C has improved the mechanical properties of the primary alloy.
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Characterization of functionally graded commercially pure titanium (CPTI) and titanium carbide (TiC) powders

  • 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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Characterization of laser deposited Ti6Al4V/TiC composite powders on a Ti6Al4V substrate

  • 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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Characterization of laser metal deposited 316L stainless steel

  • Authors: Bayode, A. , Akinlabi, Esther Titilayo , Pityana, S.
  • Date: 2016
  • Subjects: Laser metal deposition , Microhardnes , Stainless steel
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/92382 , uj:20223 , Citation: Bayode, A., Akinlabi, E.T. & Pityana, S. 2016. Characterization of laser metal deposited 316L stainless steel.
  • Description: Abstract: Laser metal deposition (LMD) is an innovative manufacturing technique that uses laser to melt powders to fabricate fully dense components layer by layer. It is capable of processing different metallic powders and can also be used for consolidating different powder to produce custom alloys or functionally graded materials (FGM). The properties of laser processed materials is dependent on the final microstructure of the parts which in turn is dependent on the LMD processing parameters. This study investigates the effects of laser power on the structural integrity, microstructure and microhardness of laser deposited 316L stainless steel. The result showed that the laser power has much influence on the evolving microstructure and microhardness of the components. The average microhardness of the samples were observed to decrease as the laser power increased due to grain coarsening.
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Characterizing the effect of processing parameters on the porosity of laser deposited titanium alloy powder

  • 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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Corrosion behaviour of laser additive manufactured titanium alloy

  • 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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Effect of laser power on the microstructural behaviour and strength of modified laser deposited Ti6Al4V+CU alloy for medical application

Effect of powder density variation on premixed Ti-6Al-4V and Cu composites during laser metal deposition

Effect of scanning speed and powder flow rate on the evolving properties of laser metal deposited ti-6al-4v/cu composites

  • Authors: Erinosho, Mutiu F. , Akinlabi, Esther Titilayo , Pityana, Sisa
  • Date: 2016
  • Subjects: Hardness , High pfr , Laser metal deposition , Microstructure , Porosity , Volume of deposited composite
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/93307 , uj:20331 , Citation: Erinosho, M.F., Akinlabi, E.T. & Pityana, S. 2016. Effect of scanning speed and powder flow rate on the evolving properties of laser metal deposited ti-6al-4v/cu composites.
  • Description: Abstract: In Laser Metal Deposition (LMD), good bonding between two similar or dissimilar materials can be achieved if the interrelationships between the processing parameters are well understood. LMD samples of titanium alloy, Ti-6Al-4V and copper, Cu were produced by varying the scanning speed and keeping other parameters constant. The deposited samples were characterized through the volume of deposited composites, microstructure, microhardness and the degree of porosity. The effect of the optimized high (powder flow rate) PFR, scanning speed varying from 0.06 m/min to 1.2 m/min and a constant power of 1kW led to a degree of porosity on the deposited composites. The varying percentages of porosities in the samples have an advance merit effect in the implantation of bones in animal and human. It was found that the existence of pores reduced as the scanning speed increases. The Vickers mirohardness was observed to increase with an increase in the scanning speed which shows an improvement in the properties of the Ti-6Al-4V/Cu composites. At low scanning velocity, the microstructure appears coarse due to the high rate of powder deposited at the same power of 1kW. The α-phase acicular microstructure decreases in size and thickness with an increase in the scanning speed. Widmanstätten structure was found in the scanning electron microscopy analyses. The results show that high PFR and low scanning speed have significantly influenced the evolving properties of the deposited composites.
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Effect of scanning speed on laser deposited 17-4PH stainless Steel

  • 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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Effect of scanning speed on the material characterizations of laser deposited titanium alloy and copper

Estimation of surface topography and wear loss of laser metal deposited Ti6Al4V and Cu

  • 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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Experimental and numerical analysis of geometrical properties of laser metal deposited titanium

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

  • 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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Gas flow rate and powder flow rate effect on properties of laser metal deposited Ti6Al4V

  • 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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