Laser metal deposition of Ti6Al4V : a study on the effect of laser power on microstructure and microhardness
- Authors: Mahamood, Rasheedat M. , Akinlabi, Esther Titilayo , Shukla, Mukul , Pityana, Sisa
- Date: 2013
- Subjects: Laser metal deposition process , Laser power , Ti6Al4V , Macroscopic banding , Microhardness , Microstructure
- Type: Article
- Identifier: uj:4896 , http://hdl.handle.net/10210/12610
- Description: The effect of laser power on the resulting microstructure and microhardness of laser metal deposited Ti6Al4V powder on Ti6Al4V substrate has been investigated. The tracks were deposited using 99.6 % pure Ti6Al4V powder of particle size ranging between 150 - 200 μm on 99.6% Ti6Al4V substrate. The laser power was varied between 0.8 - 3.0 kW while the scanning speed, powder flow rate and the gas flow rate were kept at the values of 0.005 m/sec, 1.44 g/min and 4 l /min respectively. The microstructure and the microhardness were studied using the optical microscope and the Vickers hardness tester respectively. Layer band or macroscopic banding was observed in all the samples which is phenomenon as it was only reported in the literature for multi-layer deposits. The literature attributed re-melting of the previous layers by the succeeding layers as being responsible for their formation. This study has revealed that this band could be as a result of shrinkage happening in the fusion zone as a result of the interaction of the deposited powder and the melt pool created by the substrate material. This study also reveals the relationship between the microstructure, the average microhardness and the laser power which are comprehensively discussed. The higher the laser power, the lower the density of columnar prior beta grain structure. Also the average microhardness increases as the laser power increases.
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The influence of scanning speed and number of scans on the properties of laser formed steel
- Authors: Sanusi, Kazeem Oladele , Akinlabi, Stephen , Akinlabi, Esther Titilayo
- Date: 2016
- Subjects: Laser beam forming , Scanning speed , Laser power , Mechanical , Microstructure , Micro hardness , Number of scan
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/93743 , uj:20385 , Citation: Sanusi, K.O., Akinlabi, S. & Akinlabi, E.T. 2016. The influence of scanning speed and number of scans on the properties of laser formed steel.
- Description: Abstract: Laser Beam Forming (LBF) process is an emerging and new forming method that generally requires brute force to forge the steel into the desired shape instead of using conventional methods. This study investigates the changes that occur in low carbon steel through the laser beam forming process. The parameters under investigation include variable scanning speed and number of scans at fixed laser intensity. The effect of these laser parameters on the chemical composition and properties of low carbon steel is assessed through characterisation of both the as received and LBF formed specimens. Characterizations of the laser formed steels were studied using microstructural analysis and micro hardness profiling. The results show that there is a significant increase in the mechanical properties of the LBF formed materials. Scanning power and the number of scans have a noticeable effect on the curvature achieved in the formed samples.The results obtained will contribute towards the further optimization of laser forming methods for steel for the optimization of the properties of steel using Laser Beam Forming process.
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