Role of rare-earth elements in glass formation of Al-Ca-Ni amorphous alloys

Effects of different rare-earth (RE) elements (i.e., Y, Ce, La and Yb) on the glass forming-ability (GFA) of Al-Ca-Ni alloy system were systematically investigated. The optimum addition content of all the four RE is 1 at.% and ytterbium is the most effective as far as the GFA is considered. Our analysis confirmed that proper additions of Yb could not only impede the formation of the competing alpha-Al clusters, but also enhance the liquid stability (i.e., lower the liquidus temperature). Although additions of Y, Ce and La in the Al88Ca7Ni5 can also retard the alpha-Al precipitation, nevertheless, it seemed that their large atomic size difference with Ca could destabilize the original liquid stability (i.e., increase the liquidus temperature). (C) 2011 Elsevier B. V. All rights reserved.