Evolution of stress fields during crack growth and arrest in a brittle-ductile CrN-Cr clamped-cantilever analysed by X-ray nanodiffraction and modelling

Autor: Alexander M. Korsunsky, Martin Rosenthal, Rostislav Daniel, Hynek Hruby, Jozef Keckes, Jakub Zalesak, Michael Meindlhumer, León Romano Brandt, Enrico Salvati, Christian Mitterer, Jaromír Kopeček, Juraj Todt
Rok vydání: 2021
Předmět:
Technology
STRAIN
Materials science
Cantilever
Materials Science
Cross-sectional X-ray nanodiffraction
GRADIENTS
Materials Science
Multidisciplinary
TEXTURE
02 engineering and technology
Cr
CrN
Eigenstrain modelling
Micromechanics
Multi-layer
RESIDUAL-STRESS
MICROSCALE
010402 general chemistry
FATIGUE
01 natural sciences
FRACTURE-TOUGHNESS
Stress (mechanics)
THIN-FILMS
Fracture toughness
Brittleness
Eigensrrain modelling
Residual stress
lcsh:TA401-492
General Materials Science
Composite material
Stress intensity factor
COATINGS
Science & Technology
Mechanical Engineering
021001 nanoscience & nanotechnology
0104 chemical sciences
Mechanics of Materials
Fracture (geology)
lcsh:Materials of engineering and construction. Mechanics of materials
MICROSTRUCTURE
Deformation (engineering)
0210 nano-technology
Zdroj: Materials & Design, Vol 198, Iss, Pp 109365-(2021)
'Materials and Design ', vol: 198, pages: 109365-1-109365-16 (2021)
ISSN: 0264-1275
0261-3069
Popis: In order to understand the fracture resistance of nanocrystalline thin films, it is necessary to assess nanoscopic multiaxial stress fields accompanying crack growth during irreversible deformation. Here, a clamped cantilever with dimensions of 200×23.7×40μm3was machined by focused ion beam milling from a thin film composed of four alternating CrN and Cr layers. The cantilever was loaded to 460 mN in two steps and multiaxial strain distributions were determined byin situcross-sectional X-ray nanodiffraction. Characterization in as-deposited state revealed the depth variation of fibre texture and residual stress across the layers. Thein situexperiment indicated a strong influence of the residual stresses on the cross-sectional stress fields evolution and crack arrest capability at the CrN-Cr interface. In detail, an effective negative stress intensity of −5.9±0.4MPam½arose as a consequence of the residual stress state. Crack growth in the notched Cr layer occurred at a critical stress intensity of 2.8±0.5MPam½. The results were complemented by two-dimensional numerical simulation to gain further insight into the elastic-plastic deformation evolution. The quantitative experimental and modelling results elucidate the stepwise nature of fracture advancement across the alternating brittle and ductile layers and their interfaces.
Databáze: OpenAIRE
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