Yield surface of polycrystalline thin films as revealed by non-equibiaxial loadings at small deformation

• Published in: Acta materialia Vol. 61; no. 13; pp. 5067 - 5077
• Main Authors: Djaziri, S., Faurie, D., Renault, P.-O., Le Bourhis, E., Goudeau, Ph, Geandier, G., Thiaudière, D.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2013; Elsevier
• Subjects: Applied sciences; Cross-disciplinary physics: materials science; rheology; Digital image correlation; Engineering Sciences; Exact sciences and technology; In situ biaxial tension test; Materials; Materials science; Metals. Metallurgy; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Thin films; X-ray diffraction (XRD); Yield surface; Thin films; In situ biaxial tension test; Yield surface; X-ray diffraction (XRD); Deformation; In situ; Surface layer; In situ test; X ray diffraction; Digital image correlation; Tension test; Thin film
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2013.04.031

A biaxial device developed at DiffAbs beamline of the SOLEIL synchrotron facility has been employed to determine the applied strains in film–substrate composites using both X-ray diffraction and digital image correlation measurements. Such an experimental combination is used for the first time to determine the yield surface of a polycrystalline thin film deposited on a polyimide substrate. In situ biaxial tensile tests under different biaxial planar load ratios were performed on W/Cu nanocomposite thin films deposited on flexible substrates. The effect of loading path on the yield stress of W/Cu nanocomposites is presented by considering a large range of proportional loadings. By comparing experimental results with theoretical models, this study reveals the brittle behaviour of W/Cu nanocomposite thin films at small deformations.