THE INTERRELATION OF THE SIZES AND PHASE COMPOSITION OF ZR-BASED BULK AMORPHOUS ALLOYS

Bulk amorphous Zr-based alloys are promising for their high mechanical properties and thermal stability. The predominate component of Zr in the alloy significantly improves its strength, ductility, corrosion resistance and melting point, which is important when creating various structural materials. The obtainment bulk of Zr-based alloys with an amorphous structure is not a trivial goal, but requires an ad hoc approach as the high degree of Zr oxidation and the necessary high rates of melt cooling limit realization of the amorphous state. At an insufficient cooling rate during quenching, the crystalline phases are formed, which causes change in the properties of the material itself, which in turn affects the field of practical application. Therefore, it is very important to have an idea about the change in a structure during manufacture since many properties of materials are structurally dependent.During the work, the amorphous, partially crystalline and crystalline samples of the amorphized alloy of Zr₅₅Cu₃₀Al₁₀Ni₅ composition were obtained by levitation melting and quenching into copper moulds of variable diameter. The crystalline phases formed during quenching depending on the sizes of the sample and position in it were identified. Small differences between the values of interplanar spacing of the formed phases and the tabulated ones, which can be associated with partial substitution of atoms that leads to anisotropic lattice distortions were revealed and explained. In addition, during the work, differences in the phase composition after quenching and under decomposition of the amorphous phase during heating of the alloy of this composition were also revealed.

bulk amorphous alloys, Zr-based alloys, levitation melting, X-ray diffraction