Phase competition of Cu64Zr36 and its effect on glass forming ability of the alloy.

In the present paper, crystallization behavior and glass forming ability (GFA) of Cu64Zr36 bulk metallic glass (BMG) were studied based on the crystal phase competition. Electrical resistivity and X-ray diffraction results indicate that Cu64Zr36 glass underwent a two-stage crystallization process, during which Cu10Zr7 and Cu51Zr14 crystals precipitate at first and then there are only Cu10Zr7 and Cu8Zr3 phases at the end of the second stage. Intriguingly, it was found that it is the competing phase Cu10Zr7 that weakens GFA of the Cu64Zr36 alloy, because the Cu10Zr7 precipitate is fully restrained in the cast rod when substituting Zr with 7.5at%Ti and thereby its diameter with fully amorphous structure is enlarged from 1 mm to 2 mm. [ABSTRACT FROM AUTHOR]