Magnetic Field Assisted Solidification for Transforming Manufacturing and Recycling

Lead Research Organisation: University of Birmingham
Department Name: Metallurgy and Materials

Abstract

The UK has recently become the first major economy in the world committed to bring all greenhouse gas emission to net zero by 2050. The emphasis of the metal industry, a vital part of the UK's foundation industries, but a challenging area to deep decarbonise, is to develop new ways to produce and recycle metallic materials in an energy-efficient, low-cost and sustainable manner. Solidification is an important route for manufacturing and recycling of metals and alloys. Use of magnetic fields to control solidification has been researched for several decades with a variety of applications ranging from metal purification to advanced liquid metal processing. Successful examples include removing ceramic particles from aluminium melts and improving the internal quality of cast steels. There is huge potential for magnetic fields to be used in new applications such as metal recycling and advanced processing. Magnetic fields have a strong interaction with molten metals and alloys. The interaction is governed by the induced Lorentz force, which modulate the flow of the liquid molten alloys. My recent article [1] demonstrated that the interaction between magnetic fields and molten alloys can be controlled , paving the way towards novel methods for optimizing how magnetic fields can be used in industrial-scale manufacturing and recycling processes. I believe this technology will produce substantial improvements over the current state-of-the-art in process efficiency and materials performance. My recent patent (WO2020/012199A1) using this concept has shown that contaminated iron element in aluminium alloys can be driven out by magnetic fields when aluminium alloys are at the molten state, and subsequently the impurity can be removed effectively, a challenge that metallurgists have struggled to overcome after 40 years of research.

The overarching aim of the Fellowship is to develop innovative magnet assemblies for materials manufacturing and recycling. This work will be underpinned by fundamental studies to uncover key underlying mechanisms. Based on my previous discovery and feasibility studies, in this Fellowship, I will develop patentable techniques utilizing magnetic fields for (1) the purification of recycled Al alloys, (2) the property improvement of high temperature alloys and (3) the microstructure control of metal additive manufacturing (3D printing). The Fellowship will accelerate the process of bringing the innovation from the lab to the market, as it provides unique opportunities to work with key industry partners. I will also address the underlying mechanisms for MHD control using a multidisciplinary approach, building upon my Turing Fellowship, coupling synchrotron based 4D (3D plus time) observation, data-driven analytics, and multi-physics modelling. This will not only lay strong foundations for process optimization, but also accelerate the development of entirely new solutions for incorporating MHD in manufacturing and recycling. The success of the Fellowship will increase the competitiveness of the UK's metal industries including aluminium recycling, casting, and additive manufacturing.

[1] Cai et a. Acta materialia, 2020(196): 200-209 https://doi.org/10.1016/j.actamat.2020.06.041

Publications

10 25 50
 
Description Our study shows that as an aluminium-copper alloy cools, solidification starts with the formation of faceted dendrites, which are formed through a layer-by-layer stacking of basic units that are just micrometres in size. The work also demonstrates that when rotating under a magnetic field, the size of the crystals can be refined substantially. The work has been published in Acta Materialia, and been highlighted by several news articles:
https://www.birmingham.ac.uk/news/2022/research-paves-the-way-for-stronger-alloys
Also, Materials World of IOM3, https://www.iom3.org/resource/forging-stronger-alloys.html
Exploitation Route Dendrites form not only during solidification of metals, but also during cooling of magmas and operation of batteries. I am expecting that this mechanism will be applied to explain the formation of dendrites in magmas and batteries.
Sectors Manufacturing, including Industrial Biotechology

URL https://www.iom3.org/resource/forging-stronger-alloys.html
 
Description Collaboration with Renishaw 
Organisation Renishaw PLC
Country United Kingdom 
Sector Private 
PI Contribution I have established a collaboration with Renishaw to research on additive manufacturing of Cu.
Collaborator Contribution Renishaw partially funded a research studentship with us.
Impact Undergraduate research project, still on going.
Start Year 2023