Mechanically Alloyed Magnesium Based Nanostructured Alloy Powders for Biomedical Applications

Mechanical alloying (MA) is one of the most commonly used methods in preparing metallic materials. We are especially interested in its ability to produce nanostructured materials. MA has rarely been used in producing nanostructured magnesium base alloys due to the process complexity and flammable nature of the alloy. In this work, high energy ball milling of elemental powders, Mg, Zn and Zr, was investigated for the MA of ZK50 alloy. Crystallite size, lattice strain, as a function of total milling energy (required for complete alloying) were characterized using X-ray diffraction. Scanning electron microscopy was employed to determine the influence of milling time on powder morphology. Consolidation of the milled powders into thin sheets was conducted via hot pipe rolling at 0.4 T_m. Results showed that complete alloying was achieved at 45 milling hours which was associated with particle size reduction to 600 nm and crystallite size of 8.8 nm.