Formation of crystalline Al–Ti–O thin films and their properties

• Published in: Surface & coatings technology Vol. 202; no. 24; pp. 6064 - 6069
• Main Authors: Musil, J., Šatava, V., Čerstvý, R., Zeman, P., Tölg, T.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.08.2008; Elsevier
• Subjects: Al–Ti–O thin film; Applied sciences; Corrosion; Corrosion environments; Cross-disciplinary physics: materials science; rheology; Crystallization; Exact sciences and technology; Materials science; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Methods of deposition of films and coatings; film growth and epitaxy; Oxidation resistance; Physics; Reactive magnetron sputtering; Structure; Surface treatments; Mechanical properties; Reactive magnetron sputtering; Oxidation resistance; Al–Ti–O thin film; Structure; Crystallization; Surface treatments; Al-Ti-O thin film; Sputtering; Thin films; Corrosion resistance; Magnetrons; Physical vapor deposition; Oxidation; Reactive sputtering
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2008.07.012

The article reports on the effect of addition of Ti into Al 2O 3 films with Ti on their structure, mechanical properties and oxidation resistance. The main aim of the investigation was to prepare crystalline Al–Ti–O films at substrate temperatures T s ≤ 500 °C. The films with three different compositions (41, 43 and 67 mol% Al 2O 3) were reactively sputtered from a composed Al/Ti target and their properties were characterized using X-ray diffraction (XRD), X-ray fluorescent spectroscopy (XRF), microhardness testing, and thermogravimetric analysis (TGA). It was found that (1) the addition of Ti stimulates crystallization of Al–Ti–O films at lower substrate temperatures, (2) Al–Ti–O films with a nanocrystalline cubic γ-Al 2O 3 structure, hardness of 25 GPa and zero oxidation in a flowing air up to ∼ 1050 °C can be prepared already at low substrate temperature of 200 °C, and (3) the crystallinity of Al–Ti–O films produced at a given temperature improves with the increasing amount of Ti. The last finding is in a good agreement with the binary phase diagram of the TiO 2–Al 2O 3 system.