Effect of substrate bias voltage on the composition, microstructure andmechanical properties of W-B-C coatings
| Authors | |
|---|---|
| Year of publication | 2020 |
| Type | Article in Periodical |
| Magazine / Source | Applied Surface Science |
| MU Faculty or unit | |
| Citation | |
| Web | https://doi.org/10.1016/j.apsusc.2020.146966 |
| Doi | http://dx.doi.org/10.1016/j.apsusc.2020.146966 |
| Keywords | magnetron sputtering; protective coatings; substrate bias; W-B-C alloys; fracture resistance |
| Description | Commercial ceramic protective coatings usually exhibit high hardness, but low ductility impairs their perfor-mance and application-oriented properties. Accordingly, a state-of-the-art magnetron sputtered W-B-C coating can be a promising coating for the tooling industry due to its hard yet tough characteristics.In the present study,we have employed substrate biasing to enhance the delivered energy to the growing film and have investigatedthe effect of bias voltage on the structural and mechanical behavior of W-B-C coatings. The investigations re-vealed that increasing the substrate bias voltage enhanced the re-sputtering of B and C atoms and subsequently varied the chemical composition of the coatings and significantly decreased the growthrate. It also enhanced the crystallinity of the coatings. We demonstrate how the bias voltage led to an unusual transition from a featureless to a columnar microstructure. Furthermore, it was observed that as the substrate bias voltage increased from 0V to -125V, the compositional and structural changes resulted in a slight decrease of the hardness, while a further increase in the biasvoltage to -200V enhanced the hardness. This increase was attributed to the suppression of dislocation movement and grain boundary deformation processes by solute segregation and by lattice defects. |
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