The influence of SiC particulates on fatigue crack propagation in a rapidly solidified Al-Fe-V-Si alloy

Journal Article · Mon Oct 31 23:00:00 EST 1994 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02648863· OSTI ID:6999210

Sutherland, T J ^[1]; Hoffman, P B; Gibeling, J C ^[2]

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1. Chevron USA Products Co., Richmond, CA (United States)
2. Univ. of California, Davis, CA (United States). Division of Materials Science and Engineering

The fatigue crack propagation properties of a rapidly solidified aluminum alloy are compared with those of a metal matrix composite (MMC) made of the same base alloy with the addition of 11.5 vol pct SiC particulate. The high-temperature base material, alloy 8009 produced by Allied-Signal, Inc. (Morristown, NJ), is solidified and processed using powder metallurgy techniques; these techniques yield a fine-grained, nonequilibrium microstructure. A direct comparison between the fatigue crack propagation properties of the reinforced and unreinforced materials is possible, because alloy 8009 requires no postprocessing heat treatment. As a consequence, this comparison reflects the influence of the SiC particulate and not differences in microstructure that could arise during processing and aging. The experimental data demonstrate that the SiC-reinforced material exhibits modestly superior fatigue crack propagation properties: slower crack growth rates for a given [Delta]K, a near-threshold crack growth rates. Even when the data are corrected for crack closure using an effective stress intensity factor, [Delta]K[sub eff], the composite exhibits lower crack propagation rates than the unreinforced matrix alloy. Microscopic evidence shows a rougher fracture surface and a more tortuous crack path in the composite than in the base alloy. It is argued that the lower crack growth rates and higher intrinsic threshold stress intensity factor observed in the composite are associated with crack deflection around SiC particles.

• OSTI ID: 6999210
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 25:11; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
360603 -- Materials-- Properties
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
CARBIDES
CARBON COMPOUNDS
COMPARATIVE EVALUATIONS
COMPOSITE MATERIALS
CRACK PROPAGATION
EVALUATION
FATIGUE
HEAT RESISTANT MATERIALS
IRON ALLOYS
MATERIALS
MECHANICAL PROPERTIES
SILICON ALLOYS
SILICON CARBIDES
SILICON COMPOUNDS
VANADIUM ALLOYS