The influence of sulfur on adherence of Al sub 2 O sub 3 grown on Fe-Cr-Al alloys

Journal Article · Mon Feb 01 04:00:00 EST 1988 · Oxidation of Metals; (USA)

DOI:https://doi.org/10.1007/BF00656348· OSTI ID:5575655

Sigler, D R ^[1]

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1. General Motors Research, Warren, MI (USA)

Recently a new theory was proposed to explain the effect that reactive elements have on oxide adherence. Based on data obtained on Ni-Cr-Al-Y material, this theory stated that trace quantities of sulfur in the alloy degrade adherence by weakening the metal-Al{sub 2}O{sub 3} bond. The work presented here extends this concept to Fe-Cr-Al alloys by examining Al{sub 2}O{sub 3} adherence on foil samples with various bulk sulfur levels obtained using high-temperature vacuum anneals. Results show that long-time vacuum anneals dramatically increase the adherence of the subsequently grown aluminum oxide, concurrent with removal of sulfur from the matrix. This evidence shows that the Al{sub 2}O{sub 3}-metal bond is intrinsically strong without the presence of reactive elements such as Y or rare earths in the alloy. Sulfur in the alloy, and not void formation, was found responsible for oxide spalling. In addition, voids were eliminated by reducing the sulfur concentration near the oxide-metal interface.

• OSTI ID: 5575655
• Journal Information: Oxidation of Metals; (USA), Journal Name: Oxidation of Metals; (USA) Vol. 29:1-2; ISSN 0030-770X; ISSN OXMEA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
360205 -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
ADHESION
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ANNEALING
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COATINGS
CORROSIVE EFFECTS
ELECTRON MICROSCOPY
ELEMENTS
HEAT TREATMENTS
IRON ALLOYS
METALLURGICAL EFFECTS
METALS
MICROSCOPY
NONMETALS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PROTECTIVE COATINGS
RARE EARTHS
SCANNING ELECTRON MICROSCOPY
SULFIDATION
SULFUR
SULFUR CONTENT
TEMPERATURE EFFECTS
TRACE AMOUNTS
TRANSITION ELEMENTS
VOIDS
YTTRIUM