Alloying effects of iridium on glass formation and glass-forming ability of the Zr-Cu-AI system

摘要

Alloying effects of iridium on the glass formability (GFA) of the Zr-Ir-Cu-Al system have been investigated, and several new bulk metallic glasses (BMGs) with high GFA have been successfully developed. Additions of Ir in the Zr-Cu-Al system can yield a beneficial distribution in atomic sizes, but the strong chemical interaction of the Zr-Ir atomic pair limits the maximum addable Ir contents and the resultant GFA. Our analyses indicate that the optimum composition for alloying elements is determined by not only topological but also chemical factors. Phase competition upon solidification, rather than effects from individual affecting factors, dictates the GFA of BMG systems.