Bulk Nanostructured Al-Si-Ni-Mishmetal Alloys Produced by High-Pressure Hot Compaction

Nanocrystalline Al-based alloys containing silicon (Si), rare earth metal (RE) and late transition metal (Ni), combine high tensile strength and good wear resistance. The aim of this work was to manufacture high strength bulk nanocrystalline alloys from Al-Si-Ni-Mm system. Bulk nanostructured alloys were produced by ball-milling of nanocrystalline ribbons followed by high-pressure (7.7 GPa) hot compaction (320ºC). Nanocrystalline ribbons of investigated alloys were produced by melt-spinning technique. The crystallization process was studied using differential scanning calorimeter. The phase compositions of the ribbons were characterized by X-ray diffraction, scanning and transmission electron microscopy. Vickers hardness of nanostructured compacted samples, measured with the load of 1 kG, achieved values five times higher than that of commercial 4xxx series Al alloy.