Abstract:

The current paradigm that guides much materials and manufacturing research is to optimize a materials’ (hierarchical) structure to accomplish a specific function and to then assemble different components made with different materials into ever more complex arrangements in order to realize multi-functional devices. This one material-one function paradigm, however, considerably constrains the space of what is truly possible. Moving beyond the one material-one function paradigm can potentially transform the way in which we conceptualize the solution to important
technological challenges. Novel pairings of materials and manufacturing technologies can potentially be exploited to realize spatially-tailored properties and behavior in monolithic materials and materials systems. The concept of 4D printing of polymeric and other soft materials is but an example of an enabling paradigm that can potentially be deployed over a wider materials palette.

Metal Additive Manufacturing (AM) has emerged as a transformative technology that enables the fabrication of parts and components of intricate shapes and topologies for highly customized applications. Most efforts on metal AM to date, however, have focused on controlling process conditions in order to minimize the onset of manufacturing defects and thus enhance the reliability of the manufactured parts. In our group, we have gone beyond that and have been exploring the control of process conditions and composition in order to locally tailor the chemistry, microstructure, properties and behaviour of 3D printed metals and alloys. In this talk, I will discuss some recent advances on the design of functionally graded materials (FGMs) in which chemistry and properties are spatially tailored by controlling deposited composition on a layer by layer basis. I will also discuss our recent work on metal 4D printing in which we demonstrate spatial control over the transformation characteristics of the printed component by tailoring the thermal histories during 3D printing. I will close the talk by providing some ideas on the direction of these research thrusts in the near and medium terms, particularly when it comes to novel approaches to multimaterials design in order to satisfy otherwise impossible materials design tradeoffs.