Process parameter optimization for laser metal deposited Ti6Al4V/TiC composites
- Authors: Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo
- Date: 2015-01-15
- Subjects: Laser material deposition , Microhardness , Process parameters , Titanium composites , Aluminum composites
- Type: Article
- Identifier: uj:5134 , ISBN 9789384935108 , http://hdl.handle.net/10210/14100
- Description: Laser material deposition process is an additive manufacturing technology that is used to produce functional parts directly from the three dimensional (3D) model of the part. It offers a lot of advantages in the surface modification of components, in the repair of existing worn parts, as well as for building parts that is made up of composites and functionally graded materials. This is possible because the laser metal deposition process can handle more than one material simultaneously. Processing parameters are of great importance in achieving the desired properties. Ti6Al4V is the most widely used titanium alloy in the aerospace industry. This is because of its excellent properties. However, the wear resistance behavior of these materials is not impressive because of the surface damage that occurs when they are used in applications that involves contact loadings. In this study, the effect of laser power and scanning velocity on the microstructure, the microhardness and the wear resistance properties of Ti6Al4V/TiC composites has been thoroughly investigated in order to optimize these process parameters. The Ti6Al4V/TiC composites were laser deposited with a composition ratio of 50 W% Ti64 and 50 W% TiC and at 50% overlap percentage. The laser power was varied from 1 to 3.8 kW and the scanning speed was varied between 0.03 and 0.1 m/s. The results shows that the optimum process parameters is at a laser power of about 2.0 kW and the scanning speed of about 0.055 m/s.
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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 scanning speed and energy density on the evolving properties of laser deposited Ti6Al4V/Cu composites
- 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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