Microstructural studies on EB-PVD deposited NiCrAlY, YSZ and lanthanum zirconate for thermal barrier applications
| Autor: | P Mahato, Sandip Bysakh, Lokesh Chandra Pathak, K Shravan Kumar, Suman K Mishra, Monjoy Sreemany, Satish Kumar Pandey |
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| Rok vydání: | 2012 |
| Předmět: |
Materials science
Metallurgy Surfaces and Interfaces General Chemistry Condensed Matter Physics Microstructure Electron beam physical vapor deposition Nanocrystalline material Surfaces Coatings and Films Amorphous solid Thermal barrier coating Materials Chemistry Composite material High-resolution transmission electron microscopy Layer (electronics) Yttria-stabilized zirconia |
| Zdroj: | Surface and Coatings Technology. 207:143-148 |
| ISSN: | 0257-8972 |
| DOI: | 10.1016/j.surfcoat.2012.06.045 |
| Popis: | In this work, NiCrAl (BC), La 2 Zr 2 O 7 (TC), 7% YSZ (TC), two layer structure TBCs NiCrAl (BC) + 7%YSZ (TC) and NiCrAL (BC) + La 2 Zr 2 O 7 (TC) deposition by electron beam evaporation and microstructural investigation of the surface as well as cross sections are discussed. Nanocrystalline YSZ and La 2 Zr 2 O 7 coating with desired microstructure is successfully deposited by electron beam evaporation at much lower substrate temperature of 400 °C, as compared to high temperatures 700–800 °C used in many reported literature. The adhesion of YSZ and LZ with bond coated steel substrate was found to be very good. The e-beam evaporated films are dense with very fine grained (20–40 nm) morphology and have roughness varying from 3 to 9 nm. XRD analyses reveal the desired phase formations for the bond coats and the ceramic top coats (tetragonal and cubic phase of YSZ and pyrochlore phase of LZ). HRTEM studies on the cross sections show the formation of desired columnar growth with feather like structure with entangled columns in the films for thermal barrier applications. The interfaces of the films are found to be sharp and a 5 nm thick amorphous layer is detected between the steel substrate and bond coat. |
| Databáze: | OpenAIRE |
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