Liquid-liquid demixing and microstructure of CoaCuaZr alloys with low Zr content

Liquid-liquid phase separation and its effect on the microstructure has been investigated along the quasi-binary line (Co40Cu60)100-xZrx with xANB=ANB2, 4, 6, 9 and additionally for (Co50Cu50)94Zr6 and (Co60Cu40)94Zr6. The elemental distributions and the microstructures were analyzed by scanning electron microscopy and energy dispersive X-ray spectroscopy for samples that were (i) processed by thermal cycling in alumina crucibles at 10, 20 and 30ANBK/min with simultaneous differential thermal analysis, (ii) rapidly quenched by single-roller melt spinning and (iii) quenched after having been electromagnetically levitated at various temperatures. The metastable miscibility gap of the binary CoaCu system with phase separation into Co- and Cu-rich liquids transforms into a stable miscibility gap for Zr contents 3ANB