Dissipative properties of Al-(Fe, Cr) vacuum coatings with different composite structures
| Autor: | S.S. Polishchuk, V.O. Telychko, A.I. Ustinov, V.S. Skorodzievskii, S.A. Demchenkov |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
010308 nuclear & particles physics Composite number chemistry.chemical_element 02 engineering and technology Surfaces and Interfaces General Chemistry Dissipation Atmospheric temperature range Condensed Matter Physics 01 natural sciences Indentation hardness Surfaces Coatings and Films Damping capacity Tetragonal crystal system 020303 mechanical engineering & transports 0203 mechanical engineering chemistry Aluminium Phase (matter) 0103 physical sciences Materials Chemistry Composite material |
| Zdroj: | Surface and Coatings Technology. 367:179-186 |
| ISSN: | 0257-8972 |
| DOI: | 10.1016/j.surfcoat.2019.03.074 |
| Popis: | Heterogeneous Al-(Fe, Cr) vacuum coatings were produced by electron beam vapor physical deposition (EB-PVD). It is shown that the composite structure (CS) of 85 at.% Al-(Fe, Cr) coatings consists of an aluminum-based matrix, strengthened by particles of λ-phase (CS-I), whereas that of 71 at.% Al-(Fe, Cr) coatings consists of fragmented grains of metastable bcc-phase and nano-sized particles of tetragonal Al(Cr, Fe)2 phase located along the boundaries of bcc-phase subgrains (CS-II). Effect of the different composite structures on their dissipative properties was studied. The coatings with the two types of CS have approximately the same microhardness, Hμ = 6–7 GPa, while their dissipative properties in the temperature range of 293–623 K are substantially different. It is found that the damping capacity (DC) for coatings with CS-II are 2–3 times higher than that of the coatings with CS-I(at strain amplitude of e ~ 4 × 10−4). Moreover, CS-II coatings are characterized by the amplitude-dependent damping curves with a maximum, while CS-I coatings exhibit a monotonic increase with amplitude. These differences in the coatings DC may be related to the distinction of mechanisms of energy dissipation in them. In the case of CS-I coatings, the main dissipation mechanisms are dislocation processes and grain-boundary diffusion at elevated temperatures, whereas in the case of CS-II coatings it can be due to the friction of nano-cracks edges. |
| Databáze: | OpenAIRE |
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