Mechanical characteristics of Al‐CaCO3/Zn composites
Effect of CaCO3 particle (100μm) addition on the mechanical properties of aluminium‐0.5% Si alloy has been investigated. Samples are produced using conventional stir casting method and homogenized at 5500C for four hours. Mechanical properties studied are tensile strength, tensile elongation, hardness and fracture strength. Cast samples containing 25wt%CaCO3 and 5wt%Zn exhibit the highest tensile strength (134.3MPa) owing to a breakdown of grain structure caused by the dissolution of CaAl2 and AlFeSi into the α‐aluminium matrix. Samples containing 5wt%CaCO3and 5wt%Zn have superior hardness (131.1MPa) due to high volume fraction of precipitates in the microstructure. The microstructure shows the presence of AlFeSi, Mg2Si and CaAl2intermetallics in the α‐ aluminium matrix. Keywords: CaCO3 particles, composites, precipitates, Intermetallics.