Nanoscale stress distributions and microstructural changes at scratch track cross-sections of a deformed brittle-ductile CrN-Cr bilayer
| Autor: | Peter Gawlitza, Werner Ecker, Juraj Todt, Martin Rosenthal, Sven Niese, Christian Mitterer, Jozef Keckes, Jakub Zalesak, Hynek Hruby, Michael Meindlhumer, Rostislav Daniel |
|---|---|
| Přispěvatelé: | Publica |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Technology
Materials science PLASTIC-DEFORMATION Thin films Materials Science Materials Science Multidisciplinary TEXTURE 02 engineering and technology DEFORMATION MECHANISMS Cr / C 010402 general chemistry RESIDUAL-STRESS 01 natural sciences Stress (mechanics) Brittleness CrN THIN-FILMS Scratch testing Residual stress lcsh:TA401-492 Shear stress FAILURE General Materials Science Composite material Cr computer.programming_language Science & Technology TRIBOLOGICAL CONTACT ANALYSIS Mechanical Engineering HARD COATED SURFACE 021001 nanoscience & nanotechnology Microstructure CSnanoXRD EVOLUTION 0104 chemical sciences Mechanics of Materials Scratch FRACTURE-TOUGHNESS CALCULATION lcsh:Materials of engineering and construction. Mechanics of materials Crystallite Deformation (engineering) 0210 nano-technology computer |
| Zdroj: | 'Materials and Design ', vol: 195, pages: 109023-1-109023-16 (2020) Publons Materials & Design, Vol 195, Iss, Pp 109023-(2020) |
| ISSN: | 0261-3069 |
| Popis: | In order to interpret the mechanical response of thin films subjected to scratch tests, it is necessary to elucidate local stress distributions and microstructural changes accompanying deformation across the scratch track area. Here, 50 nm synchrotron cross-sectional X-ray nanodiffraction and electron microscopy are used to characterize nanoscale multiaxial residual stress gradients and irreversible microstructural-morphological changes across a brittle-ductile film consisting of 1.2 and 2 mm thick CrN and Cr sublayers. The experimental results reveal a complex alternation of the original columnar grain microstructure and a formation of pronounced lateral and depth stress gradients, which are complemented by a finite element model. After scratching, steep gradients of in-plane, out-of-plane and shear stress distributions were revealed, ranging from −6 to 1.5 and − 1.5 to 1.5 GPa in CrN and Cr, respectively, which are furthermore correlated with microstructural changes and residual curvatures. The scratch test results in intergranular grain sliding and the formation of nanoscopic intragranular defects within CrN, while Cr sublayer's thickness reduction and pile-up formation are accompanied by a bending of columnar crystallites and localized plastic deformation. In summary, the quantitative stress data elucidate the stabilizing role of the Cr sublayer, which suppresses the bilayer's catastrophic fracture during scratch tests. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|