eTheses Repository

Laser and electron beam treatments for corrosion protection of friction stir welds in aerospace alloys

Siggs, Eirian Bethany (2010)
Eng.D. thesis, University of Birmingham.

 PDF (9Mb)

Abstract

Friction Stir Welding (FSW) is a suitable technology for aerospace structure development and is a possible replacement for mechanical fastening. To achieve the application of FSW, pre and post-weld treatments are required. A pre-weld treatment of surface preparation was required to ensure a weld with good mechanical properties. The surface preparation necessary is the removal of paint and anodising layers from aerospace alloys. Laser paint removal was assessed and designed to remove these layers with only an oxide remaining, which welded to produce high quality welds. The post-weld treatment was essential to increase the corrosion resistance of the welded area. The improvement in corrosion resistance was achieved with High Power Beam Surface Modification (HPBSM), which created a homogeneous surface through rapid surface melting and solidification. The rapid thermal processing dissolved and dispersed the precipitate solute atoms which were retained in solid solution through planar solidification. Electron beams and various lasers were used in the HPBSM processing. Excimer Laser Surface Melting (LSM) improved corrosion resistance but the layer depth was restricted by processing parameters. HPBSM processing studies using an electron beam, USP-CO$$_2$$ laser and Nd:YAG laser provided understanding on how processing parameters controlled the modified layer characteristics.

Type of Work: Eng.D. thesis. Davenport, A. (Alison) Colleges (2008 onwards) > College of Engineering & Physical Sciences School of Metallurgy and Materials TS ManufacturesTN Mining engineering. Metallurgy University of Birmingham 479
This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder.

Repository Staff Only: item control page