Among the different ways in which the aluminium alloys can be manufactured, the most popular is sheet form. Aluminium sheets are widely employed in many sectors, including packaging, transportation, and household applications, as they have high formability and low density. The key challenge of manufacturing aluminium sheets is to maintain high strength, good formability, corrosion resistance, highly recyclable and low cost.
Laura González Duque’s project is focused on producing high quality aluminium sheets with improved final performance, formability and longer durability, by means of connecting their structural features at a microscopic level (microstructure) with their resistance to surface cracking during bending. The relations found can be used to modify the manufacturing process and tailor the microstructure in a way that the final product is improved.
The most common metallic microstructure characterisation methods are two dimensional, which are a useful first approach, but there is a lot of misleading information. For example, voids could come from particles removed during sample preparation, or complicated grain shapes could be easily misinterpreted.
The principal microstructural characteristics affecting bendability are;
- the matrix, which is formed by the substructure grains - the shape and orientation of the grains form the texture which entails different bending performances
- and the microstructural inhomogeneities in the matrix, which can concentrate strain and promote premature cracking
Scanning Electron Microscopy (SEM) allows us to gain data about the grain structure to understand the sample’s properties. There are two methods:
- Electron Backscatter Diffraction (EBSD) measures the grain orientations of a flat surface of the sample.
- Backscatter Electrons (BSE) imaging detects differences in chemical composition, useful to differentiate microstructure particles and voids.
Laura’s work has utilised the Tri-beam Helios 5 (Laser-PFIB-SEM) at The University of Manchester, a Focus Ion Beam microscope that can be set to sequentially remove slices from the surface of the sample, polish them, measure an EBSD map, and take a BSE image at each slice. This method allows the capture of 3D information of the microstructure. After the experiment the EBSD maps and BSE images of each slice are merged to create 3D-EBSD and 3D-BSE volumes containing information on grain shape and orientation, particles and pore numbers, size and specific location along the three dimensions of the sample.
Using simulation models the actual microstructures can be seen, as well as the behaviour under tension, and the strain distribution on the surface during bending.
Development of the materials we use in everyday products allows us to make products more sustainable, and considerably reduce environmental damage, either in their production or lifecycle. This research contributes to the reduction of impact of a vehicle’s consumption by reducing their overall weight. This reduces the carbon footprint caused by the use of prime aluminium.
Laura González Duque studied Chemical Engineering in Santander, followed by a Masters in New Materials between Bilbao and Santander, with a thesis on corrosion of bronze alloys.
Laura’s first job was as a researcher at Grudecorr, the corrosion group in the department of Materials of the University of Cantabria, where she had the opportunity to conduct research for industrial-university collaborations, as well as internal research. With her engineering background, she went on to work at Bridgestone Corporation in Cantabria, the BSH group in Zaragoza and Element Materials Technology in Seville. Through these international companies she had the opportunity to see in person and in detail the production lines, participate in industrial Research and Development projects and a taste of quality control procedures in their factories and labs.
She received a grant to do a Master in Material Science and Engineering in the University Carlos III of Madrid, where she worked as a teaching assistant , and completed her thesis on corrosion of hard alloys with alternative compositions.
Laura’s PhD is on Crystal Plasticity and Microstructure Modelling for Rolled Aluminium Sheet at the University of Manchester.
Through opportunities offered by being part of the AMSCDT she has attended a multitude of talks in her field, participated in conferences around the world ( UK, Portugal, Norway, Spain, United States of America, and Ireland), and completed numerous workshops and courses. All of which has enriched Laura’s research and time with the CDT.
