Phase evolution in Al–Ni–(Ti, Nb, Zr) powder blends by mechanical alloying

Mechanical alloying of Al-rich Al–Ni–ETM (ETM = Ti, Nb, Zr) elemental powder blends by planetary ball milling yielded amorphous and/or nanocrystalline products after ball milling for suitable duration. Powder samples collected at different stages of ball milling have been examined by X-ray diffraction, differential scanning caloremetry and high-resolution transmission electron microscopy to examine the solid-state phase evolution. Powder blends having nominal composition of Al80Ni10Ti10 and Al80Ni10Nb10 yielded predominantly amorphous products, while the other alloys formed composite microstructures comprising nanaocrystalline and amorphous solid solutions. The amorphous Al80Ni10Ti10 alloy was mixed with different amounts of Al powder, and subjected to warm rolling after consolidation within the Al-cans with or without intermediate annealing for 10 min at 500 K to obtain sheet of 2.5 mm thickness. Notable improvement in mechanical properties has been achieved for the composite sheets in comparison to the pure Al.