“Short Range Order in Cu-Hf-Based Amorphous Alloys Studied By PAC”

L. C. DAMONTE; A.F.PASQUEVICH; L. A.MENDOZA-ZÉLIS; I.FIGUEROA VARGAS; H.DAVIES; I.TODD

Foz de Iguazú, Brasil

Conferencia; XIV International Conference on Hyperfine Interactions (HFI+NQI 2007),; 2007

UNLP-CBPF-

Copper-based ternary metallic glasses are promising for practical applications since they have high glass forming ability (GFA) and interesting combinations of mechanical properties, such as high strength, good ductility, and low cost. The Cu-Hf-Ti[1-2] system is of particular interest since the addition of Ti to binary Cu-Hf alloys improves the GFA while maintaining the high strength of the glassy phase[3]. Amorphous binary alloy samples of various copper content and ternary alloys, with various Ti substitutions for Hf, were prepared by melt-spinning. The short range order in binary and ternary amorphous alloys is investigated by means of perturbed angular correlation (PAC). The results for the as-quenched alloys indicate that the short range order can be described by a dense packing of atoms (DRP). The thermal evolution of electric field gradient (EFG) is also studied in all the samples. The intermediate and final phases, identified by PAC and X-ray diffraction, are the expected ones from the equilibrium phase diagram. These results are expected to contribute to establishing a relationship between the mechanical properties and the short range order in these amorphous alloys. [1] A. Inoue, W. Zhang, T. Zhang, K. Kurosaka, J. Mater. Res., 16 (2001) 2836. [2] I. A. Figueroa, H.A. Davies, I. Todd, J Alloys Comp., 434 (2007) 164. [3] I. A. Figueroa, P. A. Carroll, H.A. Davies, H. Jones and I. Todd, To be published.