Effects of heat treatment and reinforcement size on reinforcement fracture during tension testing of a SiC[sub p] discontinuously reinforced aluminum alloy

Journal Article · Mon Nov 01 00:00:00 EST 1993 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02646532· OSTI ID:5722165

Singh, P M; Lewandowski, J J ^[1]

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1. Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering

The effects of heat-treatment, matrix microstructure, and reinforcement size on the evolution of damage, in the form of SiC[sub p] cracking, during uniaxial tension testing of an aluminum-alloy based composite have been determined. A powder metallurgy Al-Zn-Mg-Cu alloy reinforced with 15 vol pct of either 5 or 13 [mu]m average size SiC[sub p] was heat treated to solution annealed (SA), underaged (UA), and overaged (OA) conditions. The SA treatment exhibited lower yield strength and higher ductility for both particulate sizes compared to the UA and OA conditions. The evolution of damage, in the form of SiC[sub p] fracture, was monitored quantitatively using metallography and changes in modulus on sequentially strained specimens. It is shown that the evolution of SiC[sub p] fracture is very dependent on particulate size, matrix aging condition, and the details of the matrix-reinforcement interfacial regions. SiC[sub p] fracture was exhibited by the UA and OA treatment over a range of strains, while a preference for failure near the SiC[sub p]/matrix interfaces and in the matrix was exhibited in the OA material. While the percentage of cracked SiC[sub p] at each global strain typically was equal or somewhat lower in the material reinforced with 5[mu]m average size SiC[sub p], the absolute number of cracked SiC[sub p] was always higher at each heat treatment. Damage (e.g., voids) in matrix and near the SiC[sub p]/matrix interfaces was additionally observed, although its extent was highly matrix and particle-size dependent. It was always observed that increases in stress (and strain) produced a larger amount of fractures SiC[sub p]. However, neither a global stress-based nor a global strain-based model was sufficient in converging the amount of SiC[sub p] fractured for all heat treatments and particle sizes tested.

• OSTI ID: 5722165
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Vol. 24:11; ISSN 0360-2133
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
FRACTURE PROPERTIES
COMPOSITE MATERIALS
SILICON CARBIDES
COPPER ALLOYS
CRACK PROPAGATION
DUCTILITY
HEAT TREATMENTS
MAGNESIUM ALLOYS
MATHEMATICAL MODELS
MATRIX MATERIALS
MICROSTRUCTURE
PARTICLE SIZE
VOIDS
YIELD STRENGTH
ZINC ALLOYS
ALLOYS
ALUMINIUM ALLOYS
CARBIDES
CARBON COMPOUNDS
MATERIALS
MECHANICAL PROPERTIES
SILICON COMPOUNDS
SIZE
TENSILE PROPERTIES
360603* - Materials- Properties