Low-cycle fatigue properties of a SiC whisker-reinforced 2124 aluminum alloy

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02652326· OSTI ID:6820470

Sasaki, M ^[1]; Lawson, L; Meshii, M ^[2]

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1. Nippon Metal Industry Co. Ltd., Kanagawa (Japan)
2. Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science and Engineering

Low-cycle fatigue microcracking leading to failure of smooth specimens of a powder metallurgy (PM) 2124 aluminum alloy reinforced with 20 vol pct SiC whiskers was studied. The crack size near the onset of unstable growth was inferred to be 50 to 70 [mu]m in the stress amplitude range of the present study (400 to 600 MPa, R = [minus]1) from observations of the fracture surfaces of the specimens. This corresponds to stress intensities between 1/3 to 1/2 typical values of K[sub 1c] or 1/4 to 1/9 the critical length predicted from K[sub 1c] values of 12 to 14 MPa[radical]m. The microcrack size distributions and growth data were obtained from the low-cycle fatigue specimens at various stages of fatigue, using a surface replica technique. During continued cycling, microcracks formed and were lost through linkage with other cracks. At the same time, the fraction of small cracks (< 5 [mu]m) decreased, while that of larger cracks (> 5 [mu]m) increased. The total number of cracks increased with increasing numbers of cycles.

• OSTI ID: 6820470
• 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. 25:10; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
CARBIDES
CARBON COMPOUNDS
COMPOSITE MATERIALS
CRACK PROPAGATION
FATIGUE
MATERIALS
MECHANICAL PROPERTIES
SILICON CARBIDES
SILICON COMPOUNDS
STRESS INTENSITY FACTORS