Effects of discharge voltage on Ti-O film formation on Ti-6Al-4V alloy by reactive DC sputtering

• Published in: Thin solid films 1997-01, Vol.303 (1), p.196-199
• Main Authors: Sonoda, Tsutomu, Kato, Makoto
• Format: Article
• Language: English
• Subjects: Biomaterials; Plasma processing and deposition; Sputtering; Titanium oxide
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(97)00125-9

Coating of Ti-6Al-4V alloy substrates with Ti-O films was carried out by reactive DC sputtering in Ar-O mixtures to improve the dental applicability of the alloy. The effects of discharge voltage (200–500 V) on Ti-O film formation were investigated. The Ti-O films deposited under various discharge voltages appeared to be uniform and adhesive, while their color tone and luster varied with the voltage. The films obtained under a voltage higher than 250 V were hard and durable, and the ones obtained under a voltage higher than 280 V were compact with less defects. The Ti/O ratio of each film was nearly constant in depth direction and its oxygen concentration depended on the voltage, which was detected by Auger electron spectroscopy (AES). On the basis of X-ray diffractometry (XRD), it was concluded that the suboxides such as Ti 4O 7 and Ti 6O 11 were formed in the films and that Ti 2O was also formed under a voltage higher than 400 V. The hardness of the films increased with the increase in voltage of up to 400 V, but slightly decreased at a higher voltage range. The maximum hardness higher than Hv2000 was noteworthy.