Philosophical magazine. A/Philosophical magazine. A. Physics of condensed matter. Structure, defects and mechanical properties · 1992 · 26 citations · 5 references
Natural SciencesMaterials EngineeringMaterials ScienceMaterials CharacterizationMetallic MaterialsMetallurgyAlloysAluminum OxidesMetal MaterialsMetal Matrix CompositesNanomaterial CharacterizationPhysical MetallurgyAluminium AlloysAluminum-containing AlloysAmorphous RegionsEnergy Dispersive X-ray SpectroscopyEnergy-dispersive X-ray SpectroscopyHeat Treatment EffectsHigh-resolution Electron MicroscopySpecific Orientation
Abstract The structural characterization of the whisker-matrix interface in a β-Si3N4 whisker-Al alloy 6061 composite was investigated by high-resolution transmission electron microscopy (HRTEM). It was shown that there existed a nearly amorphous layer (2–3 nm thickness) between the whiskers and the Al matrix. Mg segregation at the whisker-Al interface was revealed by energy-dispersive X-ray analysis. HRTEM observations indicated that MgO and MgAl2O4 nanocrystalline particles were easily formed at the whisker-Al interface in the composite owing to Mg segregation at the interface during the manufacturing of the composite. The Mg2Si particles (strengthening phase in the matrix) precipitated preferentially at the whisker-Al interface when the composite had been given a T6 heat treatment. Specific orientation relationships between the MgAl2O4 or Mg2Si particles and the β-Si2N4 whiskers were found. The problems associated with characterizing the microstructure of a whisker-matrix interface in an Al alloy composite reinforced by whiskers are also discussed.
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