Effect of TiC Particles Volume Fraction on the Mutual Diffusion of Al and Mg during Fabrication of Al-4.5wt%Mg/TiC via Mechanical Alloying Process

Abstract

In this work the effects of volume fraction at different milling times and impact forces, defined as the ball-to-powder weight ratio (BPR), on the elemental diffusion during mechanical alloying process of Al-4.5wt%Mg/TiC composite were evaluated and compared with the TiC free samples (Al-4.5wt%Mg alloy). X-ray diffraction patterns of the monolithic and composite samples imply the fact that a higher level of mutual diffusion of constituents, Al and Mg, happened in the matrix in the presence of TiC particles. This effect of the reinforcing particles can be attributed to the increased densities of dislocation and vacancy caused by the presence of TiC particles within the matrix-giving rise to increasing the micro-strain, lattice parameter and decreasing the crystallite size. Scanning electron microscopy (SEM) was used not only to study the morphology of the powders but also to show the fact that the TiC powders were distributed during MA process. The TEM and HRTEM results showed that powder produced in this work has a nanosize.