Özet:

The influence of desert date (Balanites Aegyptiacus) shell particulates on the physical and mechanical characteristics of aluminium matrix composites was studied. Desert date-shell particulates in varied weight percentages were added to molten A356 alloy by stir casting method for the production of the composites. The microstructure of the specimens produced was examined using optical and scanning electron microscopes. Furthermore, physical (density) and mechanical properties (tensile strength, hardness, and impact energy) were evaluated at room temperature. The composition of desert date-shell particulates was determined using an X-ray fluorescence (XRF) spectrometer. The result confirmed SiO2, to be the major constituent of the desert date (Balanites Aegyptiacus) shell particulates while Al2O3, CaO, Fe2O3, MgO, and minor oxides were in traces. The microstructure revealed networks of eutectic Si and precipitates of Mg2Si inter metallic compound in α-A356 matrix with desert dates shell particulates. It also revealed the particle sizes, particles distribution in the matrix and grain boundaries and good bonding of the particulates with the alloy matrix. The density of the composites decreased continuously with increase in desert date shell particles additions. The composite containing 115-µm particulates exhibited the highest tensile strength of 182.52 MPa at 9 wt. % reinforcement, which is 18 % higher than that of the unreinforced cast A356 alloy. It exhibited the highest hardness 85.59 HVF at 12 wt. % reinforcement, which is 22 % higher than that of the unreinforced cast A356 alloy. The composites demonstrated a progressive reduction in impact energy as reinforcement increased.

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