Effect of substitution of rare earth by mischmetal on the devitrification process of Al–X–Ni–Co (X = Y, Ce, Mm) alloys

The effect of substitution of Ce or Y by mischmetal (Mm) on the glass transition and the kinetics of crystallization of quaternary Al–Ni–Co–(Ce, Y, Mm) alloys was studied using isothermal and non-isothermal calorimetry and X-ray experiments. The alloy containing Mm shows more similarity to Ce containing alloy in all the studied properties than to Y containing alloy. The glass transition is less evident for Ce and Mm containing alloys than for the alloy containing Y. For the two former alloys, the first and the second crystallization stages are strongly overlapped and yield a fully crystallized alloy. Whereas for Y alloy, the first and the second stages are well resolved and the primary crystallization yields nanosized α-Al particles embedded in a residual amorphous matrix.