Mischmetal as an alloying addition to amorphous materials and glass formers

The present paper reports the results on full or partial replacement of Y and the rare-earth (RE) elements in Al-Y-Ni-Co, Mg-Ni-Y, Ge-Al-La and Ge-Cr-Al-RE rapidly solidified alloys by Mischmetal (Mm). The alloys studied were produced by the melt-spinning technique and examined by X-ray diffractometry and differential scanning calorimetry. Mechanical properties were also examined. Full replacement of Y/RE metals by Mm reduces the width of the supercooled liquid region in the Al and Mg-based glass formers and changes primary crystallization mechanism of Al-based metallic glass while partial replacement of Y by Mm in the Al₈₅Y₈Ni₅Co₂ metallic glass does not change its primary crystallization behavior and width of the supercooled liquid region. Mg-Ni-Mm metallic glasses show high mechanical strength of about 600 MPa which is however lower than that of the Mg-Ni-Y alloys. Al₈₅Ni₅Y₄Mm₄Co₂ metallic glass shows high tensile strength of 1120 MPa which is comparable with 1250 MPa obtained for Al₈₅Y₈Ni₅Co₂. Mm addition did not worsen glass formation in the Ge-Cr-Al-RE alloys. Ge₇₀Cr₁₆Al₁₀Mm₄ alloy contains the highest possible Ge content in the amorphous single phase so far obtained by rapid solidification.