Abstract
The microstructure and micromechanical behavior of thermally sprayed Fe-based coatings manufactured with high-velocity oxygen fuel (HVOF) and high-velocity air fuel (HVAF) processes were investigated. Fe-Cr-Ni-Si-B-C and Fe-Cr-Ni-Mo-Si-B-C powders were used as the feedstock materials. The coatings showed a highly dense microstructure with near-zero oxidation. The microstructure of the feedstock powders was better retained when sprayed with HVAF process. Differential scanning calorimetry revealed two small exothermic peaks at about 600 °C for the HVOF-sprayed coatings, without any increase in weight in thermogravimetric analysis. It suggested the re-precipitation of carbides that were dissolved during spraying due to the higher particle temperature reported by spray diagnostics system during the HVOF process (≈1800 °C) compared to the HVAF one (≈1400 °C). Micro- and nano-indentations helped to show the difference in inter-lamellar cohesive strength and, in turn, in the particle deposition mechanism. Coatings sprayed with Fe-Cr-Ni-Mo-Si-B-C composition possessed higher sliding wear resistance than that of Fe-Cr-Ni-Si-B-C due to higher nano-hardness. More specifically, HVOF-sprayed Fe-Cr-Ni-Mo-Si-B-C coating showed the largest intra-lamellar hardness, the largest elasticity, and high quality of particle interfaces which resulted in lower sliding wear rate.
| Original language | English |
|---|---|
| Pages (from-to) | 1040–1055 |
| Number of pages | 16 |
| Journal | Journal of Thermal Spray Technology |
| Volume | 25 |
| Issue number | 5 |
| Early online date | 27 Apr 2016 |
| DOIs | |
| Publication status | Published - Jun 2016 |
| Publication type | A1 Journal article-refereed |
Keywords
- iron alloys
- protective coatings
- wear resistant coatings
Publication forum classification
- Publication forum level 1
ASJC Scopus subject areas
- Condensed Matter Physics
- Materials Chemistry
- Surfaces, Coatings and Films