Vacuum heat treatment mechanisms promoting the adhesion strength of thermally sprayed metallic coatings
| Autor: | Tong Xu, Chang-Jiu Li, Guan-Jun Yang, Liu Hong, Bang-Yan Zhang, Guo-Hui Meng, Cheng-Xin Li |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Oxide Atmospheric-pressure plasma 02 engineering and technology Substrate (electronics) engineering.material 01 natural sciences Adhesion strength Metal chemistry.chemical_compound Coating 0103 physical sciences Thermal Materials Chemistry Composite material 010302 applied physics Surfaces and Interfaces General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Coating deposition Surfaces Coatings and Films chemistry visual_art engineering visual_art.visual_art_medium 0210 nano-technology |
| Zdroj: | Surface and Coatings Technology. 344:102-110 |
| ISSN: | 0257-8972 |
| DOI: | 10.1016/j.surfcoat.2018.03.010 |
| Popis: | In this study, the mechanisms responsible for enhancing the adhesion strength of thermally sprayed metallic coatings subjected to vacuum heat treatment were investigated using atmospheric plasma sprayed (APS) CoNiCrAlY coatings as an example. The formation of metallurgical bonding between the coating and the substrate, which determined the increase in the adhesion strength of the coatings, was studied by analyzing the effect of morphological changes of the oxide film in the coating. The results showed that during the vacuum heat treatment process, the oxide film formed during the coating deposition gradually broke down and subsequently shrank into round-shaped oxide inclusions. After vacuum heat treatment, the adhesion strength of the coating improved significantly. The increase in the adhesion strength was caused by the formation of metallurgical bonding between the coating and the substrate. However, the prerequisite for the formation of metallurgical bonding was that the oxide film had to break during the vacuum heat treatment process. A thermodynamic 2D model based on the thermal grooving theory was proposed to explore the essential conditions for the breaking and shrinking of the oxide film. The results predicted by the 2D model and the experimental results were in good agreement with each other and indicated that at a given temperature, the breaking of the oxide film is directly related to its thickness. |
| Databáze: | OpenAIRE |
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