'Laser free form fabrication applied to the manufacture of metallic components'

Fearon, EP (2003) 'Laser free form fabrication applied to the manufacture of metallic components'. PhD thesis, University of Liverpool.

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Item Type:	Thesis (PhD)
Additional Information:	The ability to make fully dense parts directly from powder is a fast-developing technology utilising a laser beam to create a shallow melt pool on a substrate into which powder is incorporated and subsequently melted. By moving the laser and powder feed relative to the substrate a track of solidified material can thus be created. Utilising CNC tables and/or goniometer stages this track can be laid down in a particular vector pattern, forming a layer. By repeating the process on top of this generated layer a 3-dimensional part can be made in a layered manufacturing form. Process developments have concentrated on improving the performance of laser material deposition methods in order to enhance accuracy and repeatability, reduce cost and develop new and unique uses for the process in industry. This thesis addresses the problem of maintaining dynamic control of the height of the deposited layer by the design of a modified powder delivery nozzle to be used in blown powder delivery methods of laser material deposition processes. Subsequent characterisation of the powder delivery nozzle and its effect upon the macro- and microscopic attributes of 304L stainless steel parts generated using it is carried out for comparison with current laser material deposition methods. Experiments carried out with the new nozzle system show that it is capable of being used to generate an accurate (to within 0.2mm height variation) layer height by means of alteration of the step height movement of the z-axis alone over range of input processing parameters. The thesis concludes with an examination of some of the effects of using the process in terms of existing theoretical models.
Uncontrolled Keywords:	laser, fabrication, prototyping, repair, metallic
Depositing User:	Symplectic Admin
Date Deposited:	20 Oct 2023 15:44
Last Modified:	20 Oct 2023 15:59
DOI:	10.17638/03175154
Copyright Statement:	Copyright © and Moral Rights for this thesis and any accompanying data (where applicable) are retained by the author and/or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge.
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3175154