Fabrication of thick, crack-free quasicrystalline Al–Cu–Fe coatings by electron-beam deposition
| Autor: | G. Mozdzen, T.V. Melnichenko, S.S. Polishchuk, V.А. Telychko, A.I. Ustinov, A. Merstallinger |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Fabrication Metallurgy 02 engineering and technology Surfaces and Interfaces General Chemistry Substrate (electronics) engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electron beam physical vapor deposition Thermal expansion Surfaces Coatings and Films Fracture toughness Coating Residual stress 0103 physical sciences Materials Chemistry engineering 0210 nano-technology Stress intensity factor |
| Zdroj: | Surface and Coatings Technology. 291:406-412 |
| ISSN: | 0257-8972 |
| DOI: | 10.1016/j.surfcoat.2016.03.002 |
| Popis: | Quasicrystalline Al-Cu-Fe coatings have been fabricated using electron-beam physical vapour deposition (EBPVD) at substrate temperatures in the 570–890 K range. The structure of some coatings deposited in that way contains defects, like channel cracks. It is shown that residual stresses developed during coatings cooling to room temperature may lead to the channel cracking in the coatings. X-ray diffraction analysis has demonstrated that residual stresses in the crack-free Al-Cu-Fe coatings increase linearly with deposition temperature, which is caused by the rise of thermal stresses due to the difference in thermal expansion coefficients of the coating and substrate material. The analysis of the residual stresses dependence on the deposition temperature has enabled the thermal expansion coefficient of the coating material to be determined at αc = (17.1 ± 1.3) ∗ 10− 6 K− 1.The fracture toughness of the coating material in terms of the stress intensity factor has been estimated at K 1 C = 1.68 ± 0.11 MPa m . These characteristics of the Al-Cu-Fe coatings obtained have been used for the calculation of a critical thickness, below which the crack-free structure of the coatings is retained. The obtained values of the critical thickness were compared with the results of experimental study of surfaces of the Al-Cu-Fe coatings deposited onto different substrates at various temperatures. We observed that the channel cracking was inhibited if the coating was thinner than the corresponding critical thickness. |
| Databáze: | OpenAIRE |
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