Solidification of metal alloys in pulse electromagnetic fields

Manuwong, Theerapatt

Engineering
April 2015

Thesis or dissertation


Rights
© 2015 Theerapatt Manuwong. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder.
Abstract

This research studies the evolution of solidification microstructures in applied external physical fields including in a pulse electric current plus a static magnetic field, and a pulse electromagnetic field. A novel electromagnetic pulse device and a solidification apparatus were designed, built and commissioned in this research. It can generate programmable electromagnetic pulses with tuneable amplitudes, durations and frequencies to suit different alloys and sample dimensions for research at university laboratory and at synchrotron X-ray beamlines.

Systematic studies were made using the novel pulse electromagnetic field device, together with finite element modelling of the multiphysics of the pulse electromagnetic field and microstructural characterisation of the samples made using scanning electron microscopy, X-ray imaging and tomography.

The research demonstrated that the Lorentz force and magnetic flux are the dominant parameters for achieving the grain refinement and enhancing the solute diffusion. At a discharging voltage from 120 V, a complete equaxied dendritic structure can be achieved for Al-15Cu alloy samples, the strong Lorentz force not only disrupts the growing direction of primary dendrites, it is also enough to disrupts the growing directions of primary intermetallic Al2Cu phases in Al-35Cu alloy, resulting a refined solidification microstructures. The applied electromagnetic field also has significant effect on refining the eutectic structures and promoting the solute diffusion in the eutectic laminar structure.

The research has demonstrated that the pulse electromagnetic field is a promising green technology for metal manufacture industry.

Publisher
School of Engineering, The University of Hull
Supervisor
Mi, Jiawei
Sponsor (Organisation)
Thailand
Qualification level
Doctoral
Qualification name
PhD
Language
English
Extent
13 MB
Identifier
hull:11671
QR Code