Flow stress improvement of a nickel multicrystal by physical vapor thin film deposition to reduce surface effects

Pierre-Antoine Dubos (1) , Ameni Zaouali (1) , Pierre-Yves Jouan (2) , Mireille Richard-Plouet (2) , Valerie Brien (2) , David Gloaguen (1) , Baptiste Girault (1)

1 GeM - Institut de Recherche en Génie Civil et Mécanique
2 IMN - Institut des Matériaux de Nantes Jean Rouxel

Uniaxial tensile tests were carried out on nickel sheets containing only few grains across the thickness thus presenting a so-called multicrystalline state. Pristine sheets used as reference and substrates covered by a nickel layer deposited by physical vapor deposition (magnetron sputtering) were studied. Results attest that the surface treatment affects the plastic deformation mechanisms by playing the role of a blocking barrier to dislocation movement which leads to a significant improvement of mechanical performances. The surface restructuring of the nickel sheets is efficient to stop dislocation escape through free surfaces and allows a mechanical improvement of the well-known strong mechanical softening of the multicrystals.

Mots clés: Multicrystals; Mechanical properties; Physical vapor deposition; Work-hardening

Domaines: Matériaux; Mécanique des matériaux [physics.class-ph]

Pierre-Antoine Dubos, Ameni Zaouali, Pierre-Yves Jouan, Mireille Richard-Plouet, Valerie Brien, et al.. Flow stress improvement of a nickel multicrystal by physical vapor thin film deposition to reduce surface effects. Materials Letters: X, 2022, 14, pp.100145. ⟨10.1016/j.mlblux.2022.100145⟩. ⟨hal-03671734⟩