High temperature oxidation resistance of multicomponent Cr-Ti-Al-Si-N coatings

作者：Chang Yin Yu^*; Hsiao Chia Yuan

来源：Surface and Coatings Technology, 2009, 204(6-7): 992-996.

DOI：10.1016/j.surfcoat.2009.04.009

• Cathodic-arc evaporation
• Oxidation
• Hard coating

Nanosrystalline CrAlSiN and CrTiAlSiN coatings were deposited by using a cathodic-arc deposition system with lateral rotating arc cathodes. Titanium, chromium and Al(89)Si(11) cathodes were used for the deposition of CrAlSiN and CrTiAlSiN coatings. For the high temperature oxidation test, the coated samples were annealed at 900 degrees C in air for 2 h. The oxidation characteristics of the deposited coatings were also studied by thermal-gravimetric analysis (TGA). In this study, chemical composition and bonding states of the deposited and annealed CrAlSiN and CrTiAlSiN coatings were evaluated by X-ray photoelectron spectroscopy (XPS). All the deposited Cr(0.36)Al(0.57)Si(0.07)N and Cr(0.40)Ti(0.22)Al(0.36)Si(0.02)N coatings showed B1-NaCl crystal structure and possessed nano-grain sizes of 8-12 nm. The oxide scale formed on the Cr(0.40)Ti(0.22)Al(0.36)Si(0.02)N coatings consisted of major TiO(2) at the surface region, followed by a mixed layer of Al(2)O(3) and Cr(2)O(3) phases. TiO(2) grew at an accelerated rate on to the aluminum and chromium oxide layers after oxidation at 900 degrees C. The oxidation rate of the Cr(0.36)Al(0.57)Si(0.07)N coated sample was much lower than that of Cr(0.40)Ti(0.22)Al(0.36)Si(0.02)N. A dense protective layer, mainly consisted of Al(2)O(3) and Cr(2)O(3), retarded the diffusion of oxygen into Cr(0.36)Al(0.57)Si(0.07)N. It indicated that Cr(0.36)Al(0.57)Si(0.07)N with higher Al, and Si contents possessed superior oxidation resistance lthan Cr(0.40)Ti(0.22)Al(0.36)Si(0.02)N.

• 出版日期2009-12-25