Multicomponent Si-based amorphous alloys produced by melt spinning and their crystallization behaviour

By the addition of some definite transition metals Ni, Cr and Zr to the Si-Al-Fe system, the maximum Si content for formation of an amorphous single phase was extended to 50 and 55 at% Si. The Si-based amorphous alloys are characterized by high values of electrical resistivity (11.7-12.3 μΩm) and hardness (∼ 930 HV). Their crystallization temperatures exceed 700 K, which is higher by about 100 K than those for Si₄₅Al-Fe-Cr and Si₄₅Al-Fe-Ni quaternary alloys. During heat treatment of an amorphous Si₅₅Al₂₀Fe₁₀Ni₅Cr₅Zr ₅ alloy at the temperature above the crystallization temperature, a 6-component Si₁₀Al₄Fe₂NiCrZr phase with a tetragonal structure having lattice parameters a=0.6890 nm and c=0.9402 nm is formed as a main constituent phase. The difficulty of the precipitation of the multicomponent crystalline phase with the large volume of unit cell during rapid solidification is presumed to be the main reason for the formation of the Si-based amorphous phase.