Thermal stability of fracture-resistant W-B-C coatings
| Authors | |
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| Year of publication | 2019 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Recently, several studies have documented the potential applications of W-B-C coatings with enhanced mechanical properties in the tooling industry. Such applications often require a high thermal stability due to exposure of the material to high temperatures. Here, thermal stability of magnetron sputtered W-B-C coatings up to 1100 °C was investigated after both conventional furnace annealing and RTA methods. The microstrcural changes and mechanical behavior upon annealing were studied. As-deposited coatings exhibited a nearly amorphous character with a preserved microstructure and surface morphology until 900 °C while after annealing to 1100 °C, a strong crystallization was observed. The formation of WB, W2B, WC and W2C after conventional annealing and WB, WC and W2B after RTA was suggested by XRD. Cobalt atoms were diffused into the porous coating with a columnar growth to form CoWB phase. The high-resolution XPS scans revealed a dominant fraction of W-B bonds after RTA treatment. Mechanical properties were mostly affected by chemical composition and developed phases during annealing. Fracture resistance of the coating was generally decreased after annealing to 1100 °C. No oxidation layer was observed on the coating, even after storage for one year, which suggests that W-B-C coating with high oxidation resistance. |
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