Stability of ZrBe[sub 17], and NiBe intermetallics during intermediate temperature oxidation

Journal Article · Thu Oct 01 04:00:00 EDT 1992 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(92)90413-9· OSTI ID:6986930

Chou, T C; Nieh, T G; Wadsworth, J ^[1]

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1. Lockheed Missiles and Space Co., Inc., Palo Alto, CA (United States). Research and Development Div.

This paper reports that since the finding of MoSi[sub 2] pest by Fitzer in 1955, a number of intermetallic compounds, e.g., ZrBe[sub 13], WSi[sub 2], and NiAl have also been reported to exhibit similar behavior during oxidation in air. For example, Lewis reported that catastrophic failure (total disintegration into powders) occurred in ZrBe[sub 13] when oxidized at 700[degrees]C in air. X-ray diffraction analyses revealed that the powders were composed of BeO, ZrO[sub 2] (cubic), Zr[sub 2]Be[sub 17], and unreacted ZrBe[sub 13]. Regardless of numerous cited incidents of pest in intermetallics, fundamental understanding of pest is very limited. Recently, MoSi[sub 2] pest has been studied in a great detail and fundamental insights to the mechanism of pest have been established. It is found that both single- and ply- crystalline MoSi[sub 2] are susceptible to pest, which leads to the disintegration of test samples into powder consisting of MoO[sub 3] whiskers, SiP[sub 2] clusters, and residual MoSi[sub 2] crystals. Pest is also noted to associate with substantial volume expansion of the samples. Most important, the occurrence of pest is contingent upon the formation of blisters, resulting from volume expansion by oxidation and the evaporation of MoO[sub 3] on the surfaces and grain boundary interfaces.

• OSTI ID: 6986930
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 27:7; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360102 -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
360105* -- Metals & Alloys-- Corrosion & Erosion
AIR
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ALUMINIUM ALLOYS
BERYLLIUM ALLOYS
BERYLLIUM COMPOUNDS
BERYLLIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
ELEMENTS
ENVIRONMENTAL IMPACTS
FABRICATION
FAILURE MODE ANALYSIS
FLUIDS
GASES
GRAIN BOUNDARIES
HOT PRESSING
INTERMETALLIC COMPOUNDS
MATERIALS WORKING
METALS
MICROSTRUCTURE
MOLYBDENUM COMPOUNDS
MOLYBDENUM SILICIDES
NICKEL ALLOYS
NIOBIUM ALLOYS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHASE STABILITY
POWDERS
PRESSING
REFRACTORY METAL COMPOUNDS
REFRACTORY METALS
SCATTERING
SILICIDES
SILICON COMPOUNDS
STABILITY
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
TUNGSTEN SILICIDES
X-RAY DIFFRACTION
ZIRCONIUM ALLOYS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES