Nanoengineering high-performance metallic thin films with large and tunable yield strength and ductility
Résumé
In this talk, I will present recent results for several class of advanced thin film materials including nanostructured metallic glasses (ZrCu, ZrCuAl)[1-3], high entropy alloys (Al/CoCuCrFeNi) and nanolaminates[4], highlighting how the control of microstructure affect the deformation mechanisms, enabling large/tunable mechanical properties. I will present the potential of Pulsed Laser Deposition (PLD) as a novel technique to synthetize nanostruc-tured cluster-assembled films reaching ultimate yield strength (>4 GPa) and ductility (>15 %) for ZrCuAl/O films. Moreover, I will show how nanointerfaces in fully amorphous nano-laminates (nanolayers from 100 down to 5 nm) influences the deformation behavior sup-pressing the shear bands, while achieving a balance of large ductility (> 10%) and yield strength (>2.5 GPa). Overall, our results pave the way to the development of nanostructured thin films with boosted mechanical properties and wide application range.
[1] M. Ghidelli et al., Novel class of nanostructured metallic glass films with superior and tunable mechanical properties, Acta Mater. 213 (2021) 116955.
[2] C. Poltronieri, A. Brognara, F. Bignoli, S. Evertz, P. Djemia, D. Faurie, F. Challali, C. Li, L. Belliard, G. Dehm, J.P. Best, M. Ghidelli, Mechanical properties and thermal stability of ZrCuAlx thin film metallic glasses: Experiments and first-principle calculations, Acta Mater. 258 (2023) 119226.
[3] A. Brognara, J.P. Best, P. Djemia, D. Faurie, G. Dehm, M. Ghidelli, Effect of composition and nanostructure on the mechanical properties and thermal stability of Zr100-xCux thin film metallic glasses, Mater. Design 219 (2022) 110752.
[4] G. Wu, M. Ghidelli et al., Symbiotic crystal-glass alloys via dynamic chemical partitioning, Mater. Today 51 (2021) 6-14.