A new approach to predicting compositional regions of facilitated glass formation in the Gd-Ni-Al system

Abstract

Efficient search for new compositions of amorphous alloys and significant savings in labor and material costs for the ones production require the development of reliable theoretical methods for predicting the glass-forming ability of multicomponent metal alloys. We introduce a new model for predicting the compositions of bulk amorphous metallic glasses (BMGs) and ribbons with its test application to the Gd-Ni-Al system. The proposed model parameters Θx−y(x),Θx−y(y) make it possible to forecast the location of glass-forming compositions by finding the minimum result of multiplying the PHSS parameter by the geometric coefficient Γ1,2,3(x), Γ1,2,3(y). The compositions of Gd-Ni-Al system with the best glass-forming ability (GFA), namely Gd49Ni29Al22 (BMG) and Gd40Ni51Al9 (ribbon), have been successfully determined using these parameters. The correlation between the geometric factors Γ1,2,3(x), Γ1,2,3(y) and effective packing density is shown. Amorphous alloys can be formed only at certain content of the Gd-Ni-Al system components, under which the geometric factors Γ1,2,3(x), Γ1,2,3(y) are close to the radius ratios central atom 1/central atom 2 and central atom 2/central atom 1, respectively. The results of this work open up prospects for developing reliable theoretical methods of new metal glasses prediction.