Papers by Author: Jerzy Latuch

Abstract: The aim of the present work was to compare microstructures and mechanical properties of nano-Al alloys fabricated by two different methods: (i) SPD induced grain refinement, (ii) plastic consolidation of nano-powders or nano-crystalline ribbons. SPD grain refinement has been implemented by hydrostatic extrusion, HE. The ribbons were rapidly solidified using a melt spinning methods. Plastic consolidation of powder and ribbons was conducted by warm extrusion. The results of the studies show that by applying various fabrication routes for a given chemical composition, diverse nano-structures can be obtained, which differ in terms of grain size and shape, grain boundary character and dislocation density. As a result, the alloys also differ significantly in the mechanical properties. The findings are discussed in terms of the possibilities for optimizing properties of the bulk-nano-metals.

Abstract: 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 (320°C). 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.

Abstract: Nanocrystalline Al-Si-Ni-Mm alloys have been intensively investigated in recent years. Nanocrystalline Al - based alloys containing silicon (Si), rare earth metal (RE) and late transition metal (Ni), have high tensile strength and good wear resistance. The aim of the work was to manufacture bulk nanocrystalline Al-Si-Ni-Mm system alloys and determine the influence of hot compaction at high pressure on the microstructure. The bulk nanostructured Al73Si19Ni7Mm1 and Al72Si19Ni7Mm2 alloys were produced by high pressure hot compaction of ball milled nanocrystalline ribbons.