Tribological Properties of Hard TiB 2 Thin Films Prepared at Low Temperatures Using HiPIMS.

Magnetron-sputtered WS₂ composite thin films are solid lubricants with excellent performances. However, the low hardness of the WS₂ thin films necessitates the further improvement of their wear resistance. For this purpose, an effective strategy is to alternately deposit or code posit WS₂ and a hard phase, such as TiB₂, to form hard lubricant thin films. Herein, a TiB₂ thin film was prepared under the same conditions as those used for depositing the WS₂ thin film with a dense structure and excellent tribological properties. Because of the high deposition energy of high-power impulse magnetron sputtering (HiPIMS), the TiB₂ thin film possesses a dense structure and leather-like flat surface (hardness = 24.17 GPa). The friction coefficient of the film under different loads ranges between 0.6 and 0.8. The wear rate of the thin film increases with load, mainly because of fatigue wear and abrasive wear. Under high loads, obvious furrow-like wear marks are observed. At different sliding frequencies, except 8 Hz, the friction coefficient of the film ranges from 0.6 to 0.8. The main wear mode is fatigue wear, particularly at increasing sliding frequencies. Although the film possesses a relatively high friction coefficient, its wear resistance is excellent (minimum wear rate = 1.96 × 10⁻⁶ mm³/(N·m)). [ABSTRACT FROM AUTHOR]