Glass formation and microstructure evolution in Al-Ni-RE (RE = La, Ce, Pr, Nd and misch metal) ternary systems

Abstract

Glass formation has been systematically studied in melt-spun Al-rich Al-Ni-RE (RE = La, Ce, Pr, Nd and Mm; Mm = misch metal) alloys by navigating the compositions following the observation of microstructure evolution in the resulting ribbons. The optimum glass-forming regions are similarly located around Al85Ni10RE5 and found in the centre of the composites with primary phase -Al, Al11RE3 and Al3Ni. The similarities in the critical cross-section below which a component is fully amorphous and the optimum compositions in these Al-Ni-RE systems are interpreted in terms of their competing crystalline phases and thermodynamic properties. Interestingly, it is indicated that Ni content is markedly higher than RE content in the best glass-forming alloys, which may be associated with strong interaction between Ni-Al atom pairs and the dense packing due to Ni-centred clusters.