Design of metal structures of custom composition using additive manufacturing

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Additive Manufacturing (AM) offers a new fabrication paradigm that allows almost total control over how materials are processed and connected. This versatility has led to the development of promising metal structures of customisable (graded) chemical composition which, if correctly designed, could be used to replace components now formed by joining modular elements made of different alloys. Structures of customised composition could find applications in a variety of industries especially energy, automotive and aerospace where it is oftenrequired management of extreme thermal and mechanical conditions. Using AM to control the composition within a structure would allow designers to tunemechanical and physical properties in specific locations (e.g. density, coefficients of thermal expansion, ferromagnetism, strength, etc.) and therefore enhance partperformance.Although grading chemical composition offers unique opportunities to create newoutstanding materials, there is a requirement to understand how different metalscan be intimately combined during AM to systematically achieve desired properties.This PhD aims to fill this knowledge gap by establishing guidelines for the identification of suitable material combinations for use in laser-based AM whilst fabricating reliable parts with no structural defects (e.g. cracks and voids). This will be accomplished by determining the structural and thermal behaviour of theinterface regions of the printed component (locations where dissimilar materials are in contact) as a function of the printing laser parameters. The project builds on the expertise developed at the Centre for Additive Manufacturing (CfAM) on the application of computational materials science techniques to laser AM to identify and select suitable material combinations. State-of-the-art AM software will be used to design parts with the identified materials in such a way as to satisfy the desired properties of the final part. Instrumental to the correct design of these complex parts will be the characterisation and testing of the interfaces formed in the printed structures. The PhD student will develop these structures with a combination of AM and metrology techniques, advanced materials testing, microscopy and numerical modelling, thereby gaining a broad set of skills and knowledge relevant to advanced manufacturing and materials research. The student appointed will work as part of a dynamic interdisciplinary team at CfAM, one of the largest research centres for additive manufacturing and 3D printing worldwide.