High temperature oxidation resistance of physical vapor deposited Hf-Si-B2±z thin films. (15th August 2022)

• Record Type: Journal Article
• Authors: Glechner, T.; Bahr, A.; Hahn, R.; Wojcik, T.; Heller, M.; Kirnbauer, A.; Ramm, J.; Kolozsvari, S.; Felfer, P.; Riedl, H.
• Is Part Of: Corrosion science. Volume 205(2022)
• Publication Date: 2022-08-15
• Subjects: Hf-Si-B -- Ultra-high temperature -- Si diffusion -- Oxidation -- PVD -- TEM -- APT; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110413
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: Within physical vapor deposited Hf-Si-B2±z thin films, selective diffusion-driven oxidation of Si is identified to cause outstanding oxidation resistance at temperatures up to 1500 °C. After 60 h at 1200 °C, the initially 2.47 µm thin Hf0.20 Si0.23 B0.57 thin film exhibits a dense oxide scale of only 1.56 µm. The thermally induced decomposition of metastable Hf-Si-B2±z leads not only to the formation of Si precipitates within the remaining thin film (related to a non-homogenous Si distribution after the deposition) but also to pure Si layers on top and bottom of the Hf-Si-B2±z coatings next to the excellent adherend SiO2 based scales. Graphical Abstract: ga1 Highlights: 2.5 µm thin PVD Hf-Si-B2±z coatings withstand long-term oxidation at 1200 °C. Oxide scale thickness of only 1.56 µm after 60 h, 1200 °C for Hf0.20 Si0.23 B0.57 . Single phase structure, but uneven distribution of Si in the as deposited state. Si strongly diffuses out of the Hf-Si-B2±z matrix during oxidation. Stability of the Hf-Si-B2±z coatings proven up to 1500 °C.