Strain and stress analyses on thermally annealed Ti-Al-N/Mo-Si-B multilayer coatings by synchrotron X-ray diffraction
| Autor: | Helmut Riedl, Paul H. Mayrhofer, Peter Polcik, Matthias Bartosik, Anton Davydok, Christina Krywka, Hamid Bolvardi, M. Arndt, E. Aschauer |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Intermetallic Oxide 02 engineering and technology engineering.material 01 natural sciences law.invention Stress (mechanics) chemistry.chemical_compound Coating law 0103 physical sciences Materials Chemistry Crystallization Composite material 010302 applied physics Bilayer Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Synchrotron Surfaces Coatings and Films Amorphous solid chemistry engineering 0210 nano-technology |
| Zdroj: | Aschauer, E.; Bartosik, M.; Bolvardi, H.; Arndt, M.; Polcik, P.; Davydok, A.; Krywka, C.; Riedl, H.; Mayrhofer, P.H.: Strain and stress analyses on thermally annealed Ti-Al-N/Mo-Si-B multilayer coatings by synchrotron X-ray diffraction. In: Surface and Coatings Technology. Vol. 361 (2019) 364-370. (DOI: /10.1016/j.surfcoat.2019.01.075) |
| ISSN: | 0257-8972 |
| Popis: | In order to analyse the main failure mechanism of multilayered coating material in oxidative environments, we separately investigated the cross-sectional strain/stress evolution induced by thermal loads and oxidation for the Ti-Al-N/Mo-Si-B model system. The bilayer period (Λ) of the crystalline Ti-Al-N/amorphous Mo-Si-B layers was varied between 26, 130, 240, and 1085 nm. The stress state was characterised by synchrotron X-ray nano-diffraction, using monochromatic X-ray radiation with a beam size of around 200 × 300 nm2. This allows for analysing the spatially resolved strain/stress evolution of the as-deposited state as well as after thermally treated coatings – either 1 h annealed in vacuum or ambient air at 900 °C. For small bilayer periods, the alteration of face centred cubic Ti-Al-N by amorphous Mo-Si-B layers effectively reduces the as-deposited compressive strain profile along the growth direction. Furthermore, for Λ ≤ 130 nm, the decomposition of Ti-Al-N to form hexagonal structured AlN as well as the crystallisation of the Mo-rich layers towards the intermetallics Mo5SiB2 and Mo5Si3 is significantly delayed. After oxidation, the oxide scale grows in the low-compressive stress regime, while the intact multilayer shows similar microstructural changes as the vacuum annealed coatings. |
| Databáze: | OpenAIRE |
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