The relationships between microstructure and deformation of SiC particulate reinforced Al-6061
- Univ. of Oxford (United Kingdom). Dept. of Engineering Science
The microstructure, mechanical properties and fracture mechanisms of particulate reinforced metal matrix composites have been studied. The intention is to investigate the dependence of mechanical properties on the matrix microstructure, on the size, shape and distribution of the reinforcement, and on the effect of the heat treatment of the composites. The model materials chosen are SiC particulate reinforced Al 6061. The materials have 0, 5, 10, 20 % by volume of SiC particles. with diameters of 3, 10, 30 {mu}m. They were heat treated to natural aged (NA), peak aged (PA) and over aged (OA) conditions. The compressive strength of NA specimens increased with increasing particle volume fraction provided that the particle size was less than a limiting value, and the PA specimens had the largest compressive strength but did not show any significant effect of particle size or volume fraction. The tensile strength and stiffness of the composites increased with increasing particle volume fraction in all heat treatments provided that it was over a limiting value. The PA specimens had the highest tensile strength, but the NA specimens had the highest elongation and ratio of tensile-to-yield strength. Qualitative fractographic techniques were used to examine the fracture surface of the specimens before and after each mechanical test. The presence of brittle particles in the aluminum matrix induced a significant hydrostatic stress state in the matrix during plastic deformation, which led to microvoid nucleation and growth at the matrix near the interface. The pressure level on the particle surface also induced particle cracking, then accelerating the matrix void coalescence to fracture the specimen, thus playing an important factor in the overall failure.
- OSTI ID:
- 143663
- Report Number(s):
- CONF-930246-; ISBN 0-87339-251-5; TRN: IM9413%%173
- Resource Relation:
- Conference: Advanced composites `93: international conference on advanced composite materials (ICACM), Wollongong (Australia), 15-19 Feb 1993; Other Information: PBD: 1993; Related Information: Is Part Of Advanced composites 1993; Chandra, T. [ed.] [Univ. of Wollongong (Australia)]; Dhingra, A.K. [ed.] [DuPont, Wilmington, DE (United States)]; PB: 1464 p.
- Country of Publication:
- United States
- Language:
- English
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