Sulfur segregation to deposited Al{sub 2}O{sub 3} film/alloy interface at 1000 C

Journal Article · Fri Dec 18 04:00:00 EST 1998 · Scripta Materialia

DOI:https://doi.org/10.1016/S1359-6462(98)00418-7· OSTI ID:328263

Hou, P Y; Fairbrother, D H; Roberts, J G ^[1]; Pruessner, K; Alexander, K B ^[2]

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1. Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.
2. Oak Ridge National Lab., TN (United States)

Segregation of sulfur to an oxide/alloy interface has been studied with a deposited alumina film on an iron aluminide substrate. The as-deposited film was mainly amorphous. High temperature anneal at 1000 C in an inert atmosphere prevented film growth, but caused sulfur to slowly segregate to the interface. The heat treatment also caused the film to first transform into {gamma} or {gamma}/{theta}-Al{sub 2}O{sub 3} then to {alpha}-Al{sub 2}O{sub 3}. The {alpha}-Al{sub 2}O{sub 3} grains nucleated at the film/alloy interface was more than an order of magnitude slower than segregation to the free surface, and the final concentration was 2 times higher. The extent of segregation at the interface varied significantly with different locations, and the scatter increased with annealing time. It was proposed that the segregation of S to an oxide/metal interface is controlled by the availability of interfacial sites rather than its bulk diffusion rate.

• Sponsoring Organization: USDOE, Washington, DC (United States); Electric Power Research Inst., Palo Alto, CA (United States)
• DOE Contract Number: AC03-76SF00098; AC05-84OR21400
• OSTI ID: 328263
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 2 Vol. 40; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ALUMINIUM OXIDES
ANNEALING
COMPOSITE MATERIALS
ELECTRON MICROSCOPY
INTERFACES
IRON ALLOYS
SEGREGATION
SULFUR
TEMPERATURE RANGE 1000-4000 K