Microstructural analysis of fracture toughness variation in 2XXX-series aluminum alloy composites reinforced with SiC whiskers

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

DOI:https://doi.org/10.1007/BF02652322· OSTI ID:6995957

Lee, S ^[1]; Kim, T H ^[2]; Kwon, D ^[3]

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1. Pohang Univ. of Science and Technology (Korea, Republic of). Center for Advanced Aerospace Materials
2. Sam Sung Display Devices Co. Ltd., Hwasung-Kun (Korea, Republic of)
3. Changwon National Univ. (Korea, Republic of). Dept. of Materials Science and Engineering

SiC whisker-reinforced aluminum composites have exhibited high elastic modulus, specific strength, and specific stiffness over the baseline matrix alloy, offering a potential for weight reduction and cost savings in aerospace applications. The effects of local microstructure on fracture properties in powder-metallurgy (P/M)-processed 2124/SiC/15w and 2009/SiC/15w composites are analyzed in this study. Ductility and fracture toughness of the 2009/SiC/15w, in which dispersoid-forming elements such as manganese and iron were nearly absent, were greater than in the 2124/SiC/15w, while its tensile and yield strengths were somewhat less. Microstructural examination and fracture parameter and analysis revealed that the improved fracture toughness of the 2009/SiC/15w compared to the 2124/SiC/15w was due to the increase in the critical microstructural distance, l*, when manganese-containing particles are absent. 2009/SiC/15w was also heat-treated in T4P and over aged (OA) conditions. The OA 2009 composite showed lower fracture toughness than the 2009-T4P composite and the critical fracture strain of the OA conditions was much lower, too. Detailed fractographic analysis indicated that interface precipitates facilitate premature SiC whisker failure in the OA condition.

• OSTI ID: 6995957
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Vol. 25:10; ISSN 0360-2133
• Country of Publication: United States
• Language: English

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