Investigation of boron carbide particles and mechanical milling time on the microstructure and mechanical properties of Al2024-B4C nanocomposite

In this study، mechanical milling was used to synthesize nanostructured Al2024 and Al2024-B4C nanocomposite powders in attrition mill under argon atmosphere up to 50 h. The mechanically milled powders were extruded at an extrusion ratio of 10:1. X-ray diffraction (XRD)، tensile and hardness tests were used to characterize the powders and hot extruded samples. The morphology of the mechanically milled powders was also investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Results showed that the addition of B4C particles accelerate the milling process، leading to a faster work hardening rate and fracture of aluminum matrix. Furthermore، the results revealed a lower elongation، higher strength and hardness for Al2024-B4C nanocomposite in contrast to the coarse grained Al2024 and nanostructured Al2024 matrix.