Investigation of the Structural Stability of Nanostructured Al-5.7wt.-Ni Mechanically Alloyed Eutectic Alloy Powders

摘要

In the current research, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were employed to determine the structural stability of nanostructured Al-5.7wt.%-Ni mechanically alloyed (MA) eutectic alloy powders. DSC traces were employed to determine the variation in the amount of stored energy and dislocation density as a function of milling conditions. SEM imaging was employed to investigate the degree of structural stability against grain growth as a function of the isothermal heating of MA milled powder. TEM was utilized to investigate the influence of isothermal heating on the MA nanoscale structured powders resistance to coarsening. It was found that the increasing the milling energy (RPM, ball-to-powder-ratio and time) resulted in increasing the amount of stored energy as well as increasing the dislocation density, which increased the susceptibility for grain growth.