The invention of new materials: from stone age to multi-functional lattices
Prof Norman Fleck
University of Cambridge, Engineering Department
Time & Place
Mon, 19 Nov 2018 11:00:00 NZDT in E5, Engineering Core
Historically, after new materials were discovered they gave rise to a rapid change in lifestyle, for example the transition from the stone age to the bronze age, to the iron age and more recently to the steel age. The co-evolution of weapons and armour provides an excellent example of ‘materials-driven natural selection’. Over more recent history new materials have been invented in order meet a societal need or to generate a societal need. How is this done, and what is the best way of inventing new materials? The talk will focus on the role of composition, micro-architecture and length scale of material constituents in order to achieve a particular set of material properties. Impact-resistant ship hulls made from lattice-cored sandwich-panels is an exemplar of this optimisation process. Jet engines pose a particular challenge for high strength at high temperature, and the required set of properties can only be achieved by developing composites or by multi-layers. But there remain many challenges. For example, polymeric foams of large cell size are tough but are poor thermal insulators, whereas foams with small cells are brittle but act as excellent thermal insulators. Is there a way of making tough but thermally insulating foams? The future for new materials remains bright but absolute theoretical limits exist that must be respected.
Norman Fleck is Professor of the Mechanics of Materials in the University of Cambridge's Engineering Department. He received his Ph.D. from Cambridge in 1984 on the subject of metal fatigue, and then spent a post-doctoral year at Harvard University as Lindemann Trust Fellow, working with Professor John W. Hutchinson on creep fracture. He returned to Cambridge as a lecturer in 1986, and was subsequently promoted to a Readership and then to a Professorship. He is the Founder-Director of the Cambridge Centre for Micromechanics, and was Head of the Mechanics, Materials and Design Division for 11 years, until 2009.
He is an ISI highly cited author with over 340 journal publications, and is a Fellow of the Royal Society, Royal Academy of Engineering and US National Academy of Engineering. He is on the editorial boards of several engineering journals, and has close collaborations with many US and European groups. He combines experiments and theory to develop mesoscale and macroscale constitutive models of engineering materials.