Effect of microstructure on the tensile and fracture behavior of cast A356 Al/SiC[sub p] composite

Journal Article · Thu Dec 15 00:00:00 EST 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90454-5· OSTI ID:6931845

Kim, Y H; Lee, S; Kim, N J ^[1]; Cho, K ^[2]

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

Cast Al alloys reinforced with SiC particulates offer improved resistance to wear, creep and fatigue crack initiation as well as significant increase in elastic modulus and strength in comparison with unreinforced Al alloys. In addition, they can be cast into near net shape or formed by conventional metal working techniques. However, incorporation of SiC particulates into the Al matrix substantially reduces the ductility and toughness, thereby limiting the use of these materials. A typical example of cast Al composites is the one which utilizes the A356 Al alloy (Al-7Si-0.35Mg) as a matrix alloy. The A356 Al alloy contains a high level of Si which causes the formation of a considerable amount of coarse eutectic Si particles during solidification. These particles are known to reduce the ductility of the A356 matrix alloy, but their effects on the mechanical properties of A356 Al/SiC[sub p] composites have been remained unclear. A few investigations have been conducted on the effects of the volume fraction and the size of the reinforcements. Thus, the purpose of the present study is to correlate microstructural factors such as eutectic Si particles, SiC particulates and interfacial characteristics with tensile and fracture behavior in order to get better understanding of the origin of the inherent brittleness of the cast A356 Al/SiC[sub p] composites. The composite microstructure was modified by the addition of a small amount of Sr and also by changing the solidification rate. The role of individual microstructural features in the fracture processes has also been analyzed using an in situ SEM fracture technique together with the detailed fractographic examination.

• OSTI ID: 6931845
• Journal Information: Scripta Metallurgica et Materialia; (United States), Vol. 31:12; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
COMPOSITE MATERIALS
SILICON ALLOYS
SILICON CARBIDES
EXPERIMENTAL DATA
FRACTURE PROPERTIES
MAGNESIUM ADDITIONS
ALLOYS
ALUMINIUM ALLOYS
CARBIDES
CARBON COMPOUNDS
DATA
INFORMATION
MAGNESIUM ALLOYS
MATERIALS
NUMERICAL DATA
SILICON COMPOUNDS
360603* - Materials- Properties
360602 - Other Materials- Structure & Phase Studies