Mechanical characterization of Al/Ti-6Al-4V surface composite fabricated via FSP : a comparison of tool geometry and number of passes
- Authors: Adetunla, Adedotun , Akinlabi, Esther Titilayo
- Date: 2018
- Subjects: Ti-6Al-4V , Microstructures , Composites
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/289884 , uj:31460 , Citation: Adetunla, A. & Akinlabi, E. 2018. Mechanical characterization of Al/Ti-6Al-4V surface composite fabricated via FSP : a comparison of tool geometry and number of passes.
- Description: Abstract: Aluminium alloys specifically the 1100 grade are used majorly in the manufacturing industries. However, the alloy experiences wear while being used which in turn causes reduction in the service life of this alloy. One of the most common causes of failure in aluminum alloy is wear and with the aim to improve the wear resistance of this aluminum alloy, friction stir processing (FSP) is used to fabricate the surface composite of the Al/Ti- 6Al-4V system. The Ti-6Al-4V particles were mixed into the 1100 Al alloy by employing two different tool geometries (i.e, square shape and threaded taper) with a varying number of passes from 1 - 3 passes and a varying tool rotational speed of 600 and 1200rpm. The results of this study show that the tool shape, tool speed and the number of passes play significant role in the distribution of the reinforcing particles, which consequently affect the hardness, microstructural modifications, grain size and wear resistance of these composite samples. The highest wear resistant composite was attained with threaded taper tool with 3 passes at 1200 rpm. Furthermore, the composite realized a wear resistance of 50% increment and a 40% reduction in friction coefficient compare to the 1100 Al alloy, this composite consequently exhibits the highest hardness and strength.
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Study of the mechanical behavior of LM20 alloy at various temperatures processed by die-casting
- Authors: Avvari, Muralidhar , Mashamba, Able
- Date: 2016
- Subjects: LM20 , Die-casting , Microstructures
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93347 , uj:20336 , Citation: Avvari, M. & Mashamba, A. 2016. Study of the mechanical behavior of LM20 alloy at various temperatures processed by die-casting.
- Description: Abstract: Nowadays in the current domain, manufacturing industries are competing to reduce the cost and fuel consumption rates. Especially, in automobile and aerospace applications because of the improvement of lightweight metal advantages. Magnesium, aluminum and other few materials are considered as lightweight materials to use in required applications due to their inherent properties. Therefore, in this paper tried to characterize the advances of LM20 aluminum alloy rods by using the die-casting processes at various processing temperatures followed by room temperature, 373 K, and 473 K. The main aim is to study the effect of various processing temperature on microstructures and mechanical properties of LM20 alloy. Also, this paper reveals the stability of the microstructures of LM20 aluminum alloy though the processing temperature has been increased. The tensile strength, hardness of the LM20 aluminum alloy was decreased with increase in processing temperature. Similarly, the wear, and surface roughness tests were performed on the LM20 alloy rods to understand the effect at various processing temperature.
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Microstructure evolution in AZ61 alloy processed by Equal Channel Angular Pressing
- Authors: Avvari, Muralidhar , Narendranath, S. , Able, Mashamba
- Date: 2016
- Subjects: ECAP, AZ61 alloy , Grain refinement , Microstructures
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/91541 , uj:20114 , Citation: Avvari, M. & Able, M. 2016. Microstructure evolution in AZ61 alloy processed by Equal Channel Angular Pressing.
- Description: Abstract: Magnesium and its alloys have play an strategic role in many applications like aerospace, automobile, nuclear, electrical and structural engineering due to its strength to weight ratio is very low when compared to aluminum, Titanium and steel. In the present work, AZ61 wrought magnesium alloy was processed by using Equal Channel Angular Pressing (ECAP) at three different temperatures of 483 K, 523 K and 573 K using up to four ECAP passes. A microstructural study was conducted by measuring the average grain size after each pass, for the three different processing temperatures. The mechanical properties of the processed samples were noted to improve due to the reduction in the grain size after each ECAP pass. After four ECAP passes, the average grain size of the AZ61 samples was found to be reduced to 85%, 81%, and 70% for the pressing temperatures of 483 K, 523 K and 573 K respectively. The tensile strength of the AZ61 alloy increased with increase in number of ECAP passes for each of the temperatures when compared to as-received alloy. For instances, for the processing temperature of 483 K, 523 K and 573 K, the tensile strength increased to 24%, 10%, and 12% respectively at four ECAP pass. Also, the percentage elongation of the alloy was increased with increase in processing temperatures. Moreover, fracture topographies of the tensile surfaces are illustrated through scanning electron microcopy and reveal ductile fracture than as received alloy for four passes at each ECAP processing temperature.
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Non-destructive residual stress analysis and microstructural behaviour of laser deposited titanium and copper alloy
- 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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Microstructures and dry sliding wear characteristics of the laser metal deposited Ti6Al4V/Cu composites
- 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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Influence of laser power on the surfacing microstructures and microhardness properties of Ti-6Al-4V-Cu alloys using the ytterbium fiber laser
- 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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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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