Bead shape control using multi-energy source (mes) for wire-based directed energy deposition (ded) process.

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dc.contributor.advisorDing, Jialuo
dc.contributor.advisorWilliams, Stewart W.
dc.contributor.authorChen, Guangyu
dc.date.accessioned2024-06-12T14:34:13Z
dc.date.available2024-06-12T14:34:13Z
dc.date.issued2021-11
dc.descriptionWilliams, Stewart W. - Associate Supervisoren_UK
dc.description.abstractIndependent control of layer width and height is essential to achieve a simultaneous high build rate with precision net shape and thermal control independent from deposition shape in the wire-based directed energy deposition (w-DED) process. Bead shape control using a multi-energy source (MES) method was studied to achieve independent control of layer width height of a bead for the w-DED process. This study was carried out in three stages: First, a plasma transfer arc (PTA) energy density measurement was conducted. A split anode calorimeter (SAC) was applied for the measurement of PTA energy density. A laser beam with a well-defined energy profile was used to calibrate the calorimeter without the complications of arc instability. An optimised centred grounded SAC device was introduced to reduce arc distortion. More symmetric arc profiles were obtained. The dynamic thermal characterisation of a scanning laser (SL) was then studied using both experimental and numerical approaches. SL experiments were conducted with different oscillation frequencies and laser beam sizes. An innovative solution dependent convection boundary (SDCB) method was introduced to reduce the element amount of the finite element (FE) model. Results show that the quasi-steady state SL can be applied as an equivalent stationary energy source. Finally, an SL-PTA MES system was introduced to study the MES bead shape control, a PTA was employed in the front to create an initial melt pool and melt the feedstock wire, and an SL was used behind the PTA to reshape the melt pool and precisely control the bead width. A bead shape control strategy was proposed by using the wire feeding rate to control the layer height and the scanning width to control the layer width. The experiment results verified that the SL-PTA MES has independent control of layer width and height.en_UK
dc.description.coursenamePhD in Manufacturingen_UK
dc.identifier.urihttps://dspace.lib.cranfield.ac.uk/handle/1826/22493
dc.language.isoen_UKen_UK
dc.publisherCranfield Universityen_UK
dc.publisher.departmentSATMen_UK
dc.rights© Cranfield University, 2021. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.en_UK
dc.subjectDirected energy depositionen_UK
dc.subjectBead shape controlen_UK
dc.subjectFinite element modelen_UK
dc.subjectMulti-energy sourceen_UK
dc.subjectWire-based additive manufactureen_UK
dc.subjectPlasma transfer arc (PTA) energy density measurementen_UK
dc.titleBead shape control using multi-energy source (mes) for wire-based directed energy deposition (ded) process.en_UK
dc.typeThesis or dissertationen_UK
dc.type.qualificationlevelMastersen_UK
dc.type.qualificationnamePhDen_UK

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