Microstructure and fracture of SiC-particulate-reinforced cast A356 aluminum alloy composites

Journal Article · Sun Dec 01 04:00:00 EST 1996 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/BF02595638· OSTI ID:438554

Lee, S; Suh, D ^[1]; Kwon, D ^[2]

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1. Pohang Univ. of Science and Technology (Korea, Republic of). Center for Advanced Aerospace Materials
2. Seoul National Univ. (Korea, Republic of). School of Materials Science and Engineering

A microstructural analysis of local microfracture of cast A356 Al-SiC{sub p} composites fabricated by permanent mold re-casting and squeeze-casting methods was made. Notch fracture toughness tests were conducted on these composites to identify critical fracture parameters using a stress-modified critical-strain criterion. The composite microstructure shows continuous networks of densely populated SiC and eutectic Si particles along the intercellular regions. Squeeze casting produces a more homogeneous structure and larger spacing of brittle particles and increases the tensile ductility and fracture toughness, while strength levels are almost identical to the re-casting case. The calculated values of the microstructurally characteristic distance l* for the re-cast and squeeze-cast composites are about 40 {micro}m, which is comparable to the average sizes of the intercellular network. However, the reference critical strain {bar {var_epsilon}}*{sub 0} for squeeze casting is larger than that for re-casting, showing a trend to higher ductility and fracture toughness.

• Sponsoring Organization: USDOE
• OSTI ID: 438554
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 12 Vol. 27; ISSN MMTAEB; ISSN 1073-5623
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
BRITTLENESS
COMPOSITE MATERIALS
CORRELATIONS
FRACTURE MECHANICS
FRACTURE PROPERTIES
MICROSTRUCTURE
PARTICULATES
SILICON ALLOYS
SILICON CARBIDES