Quench strengthening mechanism of Al-SiC composites

Journal Article · Thu Jul 15 04:00:00 EDT 1993 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(93)90313-H· OSTI ID:6400351

Ma, Z Y; Bi, J; Lu, Y X; Luo, M; Gao, Y X ^[1]

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1. Academia Sinica, Shenyang (China)

Incorporation of silicon carbide particulate or whisker into the aluminum matrix increases the strength and stiffness of the material. The composites also exhibit excellent elevated temperature properties and size stability, as well as good resistance to fatigue and wear. There are various theories and models about the strengthening mechanism of the composites, which is attributed to many factors. When the composites are rapidly cooled down from elevated temperature, the high density dislocation generates in the aluminum matrix adjacent to SiC particulates due to the great difference in the coefficients of thermal expansion (CTE) of SiC and Al. Volgelsang et al conducted in-situ observations on the generation process of the dislocation using HVEM. It is indicated that the dislocation density in the discontinuous SiC reinforced aluminum matrix composites is an order of magnitude greater than that of the aluminum matrix. On the basis of the experimental observations, Arsenault suggested the theory of dislocation strengthening and suggested that the high dislocation density was one of main factors for composite strengthening. A theoretical model was established, and the dislocation density which was calculated using the model was in fair agreement with the measured values. However, systematic experimental verification about the dislocation strengthening mechanism of the composites is lacking. In this paper the silicon carbide particulate and whisker reinforced pure aluminum composites were employed as model materials to understand the precipitation strengthening due to the existence of alloy elements.

• OSTI ID: 6400351
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 29:2; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
360603* -- Materials-- Properties
ALLOYS
ALUMINIUM ALLOYS
CARBIDES
CARBON COMPOUNDS
COMPOSITE MATERIALS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DISLOCATIONS
EXPANSION
FATIGUE
HARDENING
HEAT TREATMENTS
LINE DEFECTS
MATERIALS
MECHANICAL PROPERTIES
MONOCRYSTALS
QUENCH HARDENING
REINFORCED MATERIALS
SILICON CARBIDES
SILICON COMPOUNDS
THERMAL EXPANSION
WEAR RESISTANCE
WHISKERS