Tailoring atomic and microstructural heterogeneities in metallic glass thin films to control and enhance their mechanical properties - Archive ouverte HAL
Communication Dans Un Congrès Année : 2024

Tailoring atomic and microstructural heterogeneities in metallic glass thin films to control and enhance their mechanical properties

Résumé

The synthesis of advanced thin film metallic glasses (TFMGs) with engineered microstructures capable to provide a large combination of mutually exclusive mechanical properties (i.e. high strength and ductility) mitigating the shear band (SB) instability, is an open research topic. Here, I will present recent results involving two (2) strategies to finely tune the microstructure of TFMGs by introducing controlled local heterogeneities (nanointerfaces, crystalline nanolayers, nanoclustering), resulting in large and tunable mechanical behavior. Firstly, I will show the fabrication of fully amorphous Zr24Cu76/Zr61Cu39 nanolaminates by magnetron sputtering with controlled nanoscale periodicity (Λ, from 400 down to 5 nm), local chemistry and glass-glass interfaces (Fig. 1a). I will show how the SB instability can be mitigated when Λ≤50 nm, reaching remarkably large elastic/plastic deformation (16%) and yield strength (~2GPa) by micro-pillar compression, while highlighting significant chemical intermixing by HRTEM and APT during SB process (Fig. 1a). Then, I will show the potential of Pulsed Laser Deposition (PLD) to synthetize nanostructured Zr50Cu50 (%at.) TFMGs. I will show how the control of PLD process parameters enables to synthetize a variety of film microstructures among which fully amorphous compact and nanogranular reporting a large free volume content. This results in an unique and tunable mechanical behavior as shown by in situ TEM/SEM tensile & compression tests, reporting homogeneous deformation combined with a large yield strength (>3 GPa) and ductility (>9 %) product. Finally, I will focus on the synthesis of compact and nanogranular crystal/glass ultrafine nanolaminates by PLD in which ∼4 nm Al (crystalline) separate 6 and 9 nm-thick Zr50Cu50 (MG) nanolayers, reporting a high density of sharp interfaces large chemical intermixing (Fig. 1b). Nanogranular U-NLs report high yield strength (3.4 GPa) in combination with enhanced elastoplastic deformation (>6%, in compression). Moreover, this structure effectively block the percolation of SBs even reaching >15% deformation due to the larger free volume content and the presence of ultrafine crystal-glass nanointerfaces (Fig. 1b). Overall, I will show how managing microstructural heterogeneities in TFMGs is an effective strategy to control their deformation behavior, boosting their mechanical properties with potential for industrial applications.
Fichier non déposé

Dates et versions

hal-04755035 , version 1 (26-10-2024)

Identifiants

  • HAL Id : hal-04755035 , version 1

Citer

Francesco Bignoli, Andrea Brognara, Philippe Djemia, Andrea Li Bassi, Gerhard Dehm, et al.. Tailoring atomic and microstructural heterogeneities in metallic glass thin films to control and enhance their mechanical properties. Characterization and properties of interface-dominated materials (InMa 2024), Nov 2024, Aachen (Aix la Chapelle), Germany. ⟨hal-04755035⟩
25 Consultations
0 Téléchargements

Partager

More