Effect of pressure and temperature on microstructure of self-assembled gradient AlxTi1-xN coatings
| Autor: | Ronald WEIßENBACHER, Jakub Zalesak, Jan Michalička, Mario Lessiak, Christoph Gammer, Bernhard Sartory, Reinhard Pitonak, Juraj Todt, I. Matko, Jozef Keckes, Margarethe Traxler |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
protective coating
Morphology (linguistics) Materials science Superlattice self-assembly Surfaces and Interfaces Chemical vapor deposition engineering.material Microstructure Nanocrystalline material Surfaces Coatings and Films Coating lcsh:TA1-2040 LP-CVD Ultimate tensile strength TEM Materials Chemistry engineering Self-assembly TiAlN Composite material lcsh:Engineering (General). Civil engineering (General) X-ray nanodiffraction |
| Zdroj: | 'Coatings ', vol: 11, pages: 416-1-416-15 (2021) Coatings Volume 11 Issue 4 Coatings, Vol 11, Iss 416, p 416 (2021) |
| ISSN: | 2079-6412 |
| Popis: | The correlation between structural properties of Al-rich self-assembled nano-lamellar AlxTi1−xN coatings and process parameters used during their chemical vapor deposition (CVD) remains unexplored. For this article, two gradient AlxTi1−xN coatings were prepared by a stepwise increase in temperature and pressure in the ranges of 750–860 °C and 1.56 to 4.5 kPa during the depositions at a constant composition of the process gas mixture. The cross-sectional properties of the coatings were analyzed using X-ray nanodiffraction (CSnanoXRD) and electron microscopy. Experimental results indicate that the variation of the process parameters results in changes in microstructure, grain morphology, elastic strain, nanolamellae’s chemistry and bi-layer period. At temperatures of ~750–800 °C and pressures of 2.5–4.5 kPa, preferably cubic nanolamellar grains are formed, whose microstructure correlates with the build-up of tensile stresses, which become relaxed in coating regions filled with nanocrystalline grains. CSnanoXRD superlattice satellite reflections indicate the period of the cubic Al(Ti)N-Ti(Al)N bilayers, which changes from 6.7 to 9 nm due to the temperature increase from 750 to ~810 °C, while it remains nearly unaffected by the pressure variation. In summary, our study documents that CVD process parameters can be used to tune microstructural properties of self-assembled AlxTi1−xN nanolamellae as well as the coatings’ grain morphology. |
| Databáze: | OpenAIRE |
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