Abstract
TiB2/TiC multilayer coatings were synthesized in a dual-cathode, non-reactive, unbalanced magnetron sputtering system with stationary and rotating substrates. All coatings are polycrystalline with TiB2(001) preferred orientation and have a multilayer structure. Coatings synthesized with stationary substrates have high compressive stress (4-7 GPa), and their hardness is slightly enhanced (∼25%) over the rule-of-mixture value. Coatings grown with substrate rotation have much lower compressive stress (<2 GPa) and high hardness (>60 GPa). Substrate rotation appears to improve mobility of surface species and allows more time for surface diffusion, thus resulting in denser films with lower void concentration. This may explain the substantial difference in hardness enhancement between these two cases. After being annealed in an inert environment (vacuum or argon) at 1273 K for 1 h, these multilayer coatings retain their layer structure. Moreover, most coatings have improved crystallinity and increased room-temperature hardness after such annealing.
Original language | English (US) |
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Pages (from-to) | 591-596 |
Number of pages | 6 |
Journal | Surface and Coatings Technology |
Volume | 177-178 |
DOIs | |
State | Published - Jan 30 2004 |
Funding
This work was supported by the NSF-DMI grant number DMI-9877136 and the Northwestern University Center for Surface Engineering and Tribology through the NSF-IGERT grant number DGE-0114429/001. We wish to thank Chirag D. Patel for assistance in hardness measurements and Dr. Shu-You Li in microscopy studies.
Keywords
- Hardness
- Internal stress
- Sputtering
- Substrate rotation
- Thermal stability
ASJC Scopus subject areas
- General Chemistry
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry