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ABSTRACT: The particle/matrix interfaces in SiCp/AZ91 composite fabricated by stir casting were investigated using transmission electron
microscope (TEM) equipped with ultra-thin window energy dispersive X-ray analysis (EDAX) system. Chemical reactions indeed
occurred at the interfaces. According to EDAX results, the interfacial reaction products are considered to contain Al4C3, MgO, and Mg2Si phases. The interfaces can be classified into three types (interfaces I, II, and III) according to morphological features
of the interfaces: (1) for interface I, interfacial reaction products were in direct contact with the surface of SiCp; (2)
for interface II, interfacial reaction products were not in direct contact with the surface of SiCp; (3) for interface III,
interfacial reaction products were not observed at the interfaces, i.e., interface III was simply formed by the two surfaces
of SiCp and matrix. Mg17Al12 and Al8Mn5 precipitate phases heterogeneously nucleated at the particle/matrix interfaces.
Journal of Materials Science 05/2012; 44(11):2759-2764. · 2.02 Impact Factor
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ABSTRACT: A ceramic coating was synthesized on the surface of SiCw/AZ91 magnesium matrix composite by means of microarc oxidation (MAO) technique. Scanning electron microscope (SEM) was employed to characterize the surface morphology and cross-section microstructure of the coating. The phase structure and the chemical composition of the ceramic coating were analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the coating was evaluated by immersion test and electrochemical method. The results showed that the corrosion rate of the coated SiCw/AZ91 composite was decreased greatly compared with that of the bare composite because of the protective microarc oxidation coating.
Materials Letters.
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ABSTRACT: The texture of the Mg/Al laminated composite fabricated by accumulative roll bonding was measured by neutron diffraction. The texture type of the Mg layer was typical rolling texture and the dominant texture of the Al layer was β-fiber rolling texture with scatter around the ideal orientations. The significant waviness structure caused by the shear band reduced both the intensity and the sharpness of the rolling texture of both Mg and Al layers.
Scripta Materialia.
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ABSTRACT: SiCp/AZ91 magnesium matrix composite was fabricated by stir casting. The as-cast ingots were cut into cylindrical billets, and then forged at different temperatures (320, 370, 420, 470 and 520 °C) at a constant RAM speed of 15 mm/s with 50% reduction. The microstructure evolution of the composites during forging was investigated by optical microscope, scanning electron microscope, and transmission electron microscope. The texture of the forged composites was measured by neutron diffraction. Mechanical properties of the composite at different forging temperatures were tested by tensile tests at room temperature. It was found that a strong basal plane texture formed during forging, and the intensity of basal plane texture weakened as forging temperatures increased. The particle distribution in the composite was significantly improved by hot forging. Typical microstructures were obtained after forging at different temperatures and the composite with different microstructures offered different mechanical properties during tensile test.
Materials Science and Engineering: A.
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Magnesium 8th International Conference on Magnesium Alloys and Their Applications (2009),282-287.
