STRUCTURAL COMPARISON OF AMORPHOUS, NANOCRYSTALLINE AND MICROCRYSTALLINE Al_(90)Fe_7Nb_3 ALLOYS

摘要

This work presents the structural comparison of Al_(90)Fe_7Nb_3 alloys obtained by different techniques: (i) partly amorphous powder alloy produced by mechanical milling and their consolidation by hot extrusion (cylindrical bar), (ii) from millimeter portion by casting centrifuged system (square shape), and (iii) from millimeter portion by melt-spinning (ribbon shape). The cylindrical consolidated alloy presented an Al matrix with Al_3Nb and Al_(13)Fe_4 nano-phases (intermetallic compounds), the square consolidated alloy resulted in the same structure composed of Al matrix with Al_3Nb and Al_(13)Fe_4 in micro-phase scale. On the other hand, the ribbon alloy exhibits an amorphous matrix with primary Al nanocrystals (fcc-Al phase).