The morphological and structural development of internal oxides in nickel-aluminum alloys at high temperatures

Journal Article · Fri Oct 01 04:00:00 EDT 1982 · Oxid. Met.; (United States)

DOI:https://doi.org/10.1007/BF00662034· OSTI ID:6597927

Stott, F H; Bastow, B D; Shida, Y; Whittle, D P; Wood, G C

The formation and development of internal oxides in Ni-Al alloys containing 1-4 wt.% Al in Ni-NiO packs and in 1 atm oxygen at 800 to 1100/sup 0/C have been studied. The internal oxide particles were relatively fine, closely spaced, and mainly acicular, although more granular near the surface. They were identified as Al/sub 2/O/sub 3/ at the advancing front, but NiAl/sub 2/O/sub 4/ at the surface and at a significant distance from that surface. Growth of internal oxide particles resulted in the development of significant compressive stresses in the internal oxide zone when formed in Ni-NiO packs. These stresses led to grainboundary sliding at the higher temperatures and extrusion of weak, internal oxide-denuded zones adjacent to alloy grain boundaries. At the lower temperatures, these stresses also resulted in significant preferential penetration of oxides down grain boundaries and sub-grain boundaries. Stress development and resulting phenomena were much less significant during oxidation in 1 atm oxygen because vacancies injected from the external NiO scale accommodated the volume increase during growth of internal oxide particles.

• Research Organization: Univ. of Manchester, Manchester
• OSTI ID: 6597927
• Journal Information: Oxid. Met.; (United States), Journal Name: Oxid. Met.; (United States) Vol. 18:3/4; ISSN OXMEA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CORROSION
CRYSTAL STRUCTURE
ELEMENTS
INTERGRANULAR CORROSION
MEDIUM PRESSURE
MICROSTRUCTURE
MORPHOLOGY
NICKEL ALLOYS
NICKEL BASE ALLOYS
NICKEL COMPOUNDS
NICKEL OXIDES
NONMETALS
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PRESSURE EFFECTS
STRESSES
TRANSITION ELEMENT COMPOUNDS
VERY HIGH TEMPERATURE