Microstructure and tribological behavior of plasma sprayed NiCrAlY/WC-Co/cenosphere/solid lubricants composite coatings
| Autor: | Mahantayya Mathapati, Mrityunjay Doddamani, M. R. Ramesh |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Scanning electron microscope 02 engineering and technology Surfaces and Interfaces General Chemistry Tribology engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure Surfaces Coatings and Films 020303 mechanical engineering & transports 0203 mechanical engineering Coating Cenosphere Materials Chemistry Lubrication engineering Composite material 0210 nano-technology Dry lubricant Tribometer |
| Zdroj: | Surface and Coatings Technology. 354:92-100 |
| ISSN: | 0257-8972 |
| Popis: | Present investigation deal with NiCrAlY/WC-Co/Cenosphere/MoS2/CaF2, NiCrAlY/WC-Co/Cenosphere/MoS2/CaSO4 and NiCrAlY/WC-Co/Cenosphere coatings deposited on MDN 321 steel using atmospheric plasma spraying. Tribological properties of MDN 321 steel and coatings are evaluated from room temperature (RT) to 600 °C under dry lubrication conditions using a pin on disc high-temperature tribometer. Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS) are used to characterize the coatings. Presence of cenospheres in these coatings might effectively reduce wear acting as localized regions accumulating wear debris. The result shows that wear rate of all the coatings are lower as compared to MDN 321 substrate at all the test conditions. NiCrAlY/WC-Co/Cenosphere/MoS2/CaF2 and NiCrAlY/WC-Co/Cenosphere/MoS/CaSO4 coatings registered lower friction coefficient as compared to NiCrAlY/WC-Co/Cenosphere coating and MDN 321 substrate. Characterization of the NiCrAlY/WC-Co/Cenosphere/MoS2/CaF2 and NiCrAlY/WC-Co/Cenosphere/MoS2/CaSO4 coatings worn out surface suggests that MoS2 provides lubrication at 200 °C and formation of CaMoO4, MoO3 through tribo chemistry reaction at higher temperature provides lubrication at 600 °C. SEM micrograph of worn surface demonstrates that the main wear mechanism is plowing and delamination. |
| Databáze: | OpenAIRE |
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