Cryomilling and spark plasma sintering of nanocrystalline magnesium-based alloy

The microstructure characteristics of nanocrystalline magnesium-based alloy processed by cryomilling and spark plasma sintering were investigated. The as-received and cryomilled powders and the consolidated bulk material were characterized by scanning and transmission electron microscopies, x-ray diffraction, and electron dispersive spectroscopy techniques. The cryomilled powders resulted in an average grain size of 25 nm. After spark plasma sintering, a bimodal grain size distribution with coarse grains around 500 nm and fine grains of 52 nm, which is one of the smallest grain sizes reported in bulk nanostructured Mg alloys, was found. Our results suggest this novel process as a viable method to provide new opportunities for the development of nanostructured Mg-based alloys.