Christopher Hutchinson

Professor Christopher Hutchinson is the Alcoa Distinguished Professor in the Department of Materials Science & Engineering at Monash University in Melbourne, Australia. He obtained his PhD from the University of Virginia (USA), and after a post-doc at Grenoble Institute of Technology (France), returned to Melbourne to take up a Faculty position at Monash University.

His interests are in the physical and mechanical metallurgy of engineering alloys with a particular emphasis on steels, Al alloys and Cu and brasses. His work is split approximately equally between theory/modelling and experiment, and around half of his work is in collaboration with industry. For the last 10 years he has led the Woodside Energy FutureLab at Monash and leads the activities on 3D metal printing in this centre.

https://www.monash.edu/engineering/christopherhutchinson

Abstract

Powder-bed fusion (PBF) as a platform for site-specific micro- and mesostructure control and the fabrication of architectured materials

The defining feature of PBF is the point-by-point and layer-by-layer fabrication process. The elementary building block is the melt pool, and the component is built melt pool-by-melt pool. During printing, the user has unprecedented levels of control over the energy source. The beam power, spot size, scan speed, scan pattern, overlap, multi-pass, focus, shape, frequency, and even the number of beams used, provide incredible flexibility over the thermal history of essentially every melt pool volume during printing. The control of this thermal history provides the opportunity to control the micro-and mesostructures formed. When this is done site-specifically, in 3D, new types of metals with controlled internal mesoscale architectures can be created, giving access to new combinations of properties. The concept of ‘architectured materials’ is not new, but their Achilles heel has always been the challenges in fabrication. PBF provides a platform for building architectured materials that the additive manufacturing community is beginning to explore. One might imagine that in the future, no PBF component put into service will contain the type of mesoscopically homogenous structures we currently fabricate and use. Components containing internal 3D architectures designed to maximize performance will become the norm. In this talk, we summarise the families of approaches so far used for site-specific micro- and mesostructure control in PBF (local solidification control, local heat treatments, local composition control) and discuss a couple of examples in depth to emphasise the different fields that need to come together to realise architectured materials by PBF. We conclude by highlighting an important question that requires attention - with all the tools now available to exert control in a site-specific manner during PBF, how do we determine which micro- and mesoscale architectures to design into a certain part geometry to maximize its performance.