Deformation and cracking phenomena in cold sprayed 6061 Al alloy powders with nanoscale aluminum oxide films

This paper presents deformation and cracking phenomena associated with the cold spray of nanoscale surface oxide layers 6061 Al alloy powders. The structure top film was revealed via Focused Ion Beam (FIB), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS). observations show layer characteristics most likely matches crystalline γ-Al 2 O 3 . Phenomena contacts, contact-induced elastic-plastic deformation, heating, are then studied using a combination analytical models, Finite Element Analysis (FEA) Molecular Dynamics (MD) simulations. MD simulations also used to obtain estimates young's moduli, strains failure, fracture energies films. results from microscopy incorporated into bi-linear Johnson- Cook finite element due impact aluminum powder particles similar substrates layers. impacts shown result in localized splat along that expose fresh metallic surfaces high temperature contacts (at temperatures above recrystallization for aluminum/6061 Al) can give rise bonding mechanical interlocking. implications discussed design processes fabrication repair structures.