Mechanism of Reduction in Grain and Particle Sizes of Nix-Fe100x Nanopowder by Mechanical Alloying

Abstract

Ball milling with high energy for mechanical alloying was followed to make Ni-Fe alloy powders from elemental Ni and Fe powders having the sizes of 80 µm (Ni) and 25 µm (Fe). Preparations were carried out at room temperature with various duration of time ranging from 2 to 100 hours using ball milling with high energy. Analyses based on X-ray diffraction pattern and particle size analyzer were used for characterization of powders. During ball milling, it was observed that the reduction of grain size and particle size occurred in a stepped fashion. This observation indicates that the reduction in grain size and particle size occurs in a successive cyclic fashion, contrary to the expectation of concurrent reduction.