الفهرس 
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Abstract
Metal-matrix composites (MMCs) are attracting considerable interest worldwide because of their superior mechanical and tribological properties. This study describes multifactor based on the experiments that were applied to investigate aluminium matrix composite reinforced with 5, 10 and 15 wt.% alumina or iron particles. Mechanical mixing technique was used for the fabrication process. Sintering was carried out in a vacuum furnace at 600 °C for 1 hr. The sintered products have been characterized by X-ray diffraction (XRD), optical and scanning electron microscopes. The effects of alumina or iron percentage on the density, microstructure, thermal conductivity, hardness and compression strength has been investigated, also the effect of iron particles addition on the magnetic properties of Al composites was studied. The results showed that sample containing 5wt.% Alumina is near fully dense. Also it has the highest hardness and compression strength values. This is due to the strengthening effect of the alumina ceramic oxide. XRD patterns for Al2O3- Al composites didn’t refer to any new phase rather than Al and Al2O3. Samples containing 5, and 10wt.% Fe indicated the presence of Al and Fe peaks only, while sample containing 15wt.% Fe revealed Al and Al13Fe4 intermetallic peaks. The results showed that both densification and thermal conductivity of the composites decreased by increasing the iron content. The presence of iron in the composite improved the compressive strength and the hardness. The strengthening was understood in the view of grain refinement of the matrix, the uniform distribution of the Fe particles, and the formation of Al13Fe4 intermetallic. The measured magnetization values were 0.3816 emu/g for 5wt.% Fe sample and increased up to 0.6597 for 10wt.%, then decreased to 70.20 x 10-3 for 15wt.%Fe sample. This can be explained by the formation of the diamagnetic Al13Fe4 intermetallic compound between Al and Fe in the higher Fe content sample which was detected by XRD analysis.