Effect of microalloying on the formation and stability of the Ti-Zr-Ni icosahedral quasicrystal

The influence of small additions of Cu, Ag, Au, Pt, Pb, and Si on the formation and stabilization of Ti-Zr-Ni icosahedral quasicrystal (i-phase) are discussed. Among these elements, only the addition of Ag improved the stability and formability of the i-phase, significantly. A small amount of supercooling and the nucleation and growth of only the i-phase from the liquid during levitation melting experiments signal the presence of well developed extended icosahedral short range order (ISRO) in the liquid. These results are explained in terms of a better atomic size ratio of Ag to Zr to form ISRO.