Evaluating Microstructure and High-Temperature Shear Behavior of Hot Extruded Al-Al₁₃Fe₄ Nanocomposite

Abstract

The microstructure and mechanical properties of extruded aluminum matrix composites reinforced with novel Al 13 Fe 4 complex metallic alloy (CMA) nano-particles were investigated. The large grained structure of the hot pressed matrix was refined after addition of Al 13 Fe 4 CMAs, the effect being more pronounced for Al-5 mass% Al 13 Fe 4 composite. The hot pressed specimens were subjected to uniaxial hot extrusion process (with a 9 : 1 ratio at 400°C). This had a great effect on the microstructural evolution of the composites. High-temperature shear punch test (SPT) was employed to investigate the effects of 110 mass% Al 13 Fe 4 additions on the microstructure and mechanical properties of the asextruded Al/Al 13 Fe 4 composite. The shear behavior of the alloys was investigated in the temperature range of 25350°C. Al-5 mass% Al 13 Fe 4 nanocomposite had the highest shear strength among all the materials tested at high temperature (150, 250 and 350°C), mainly due to the semiideal dispersion of the thermally stable Al 13 Fe 4 nano-particles, and the refined microstructure of the extruded specimen, which results in pronounced enhancement in mechanical properties. These thermally resistant particles are believed to increase the resistance of the composite against the applied shear stress in the deformation zone during the subjection of the material to SPT.