Crystalline to amorphous transition in solids upon high-pressure torsion

Highlights: • Ti–Ni, Zr and Fe-based alloys were deformed using HTP processing. • Ability to deformation-induced amorphization (DIA) of these alloys was studied. • Amorphization is determined by mechanical, thermodynamic and concentration factors. • The smaller stability of phases the higher their ability to deformation amorphization. • There is the difference between of DIA and to thermal amorphization in the nature. - Abstract: The amorphization behavior of the crystalline multicomponent Ni₅₀Ti₃₀Hf₂₀, Ti₅₀Ni₂₅Cu_25, Zr₅₀Ni₁₈Ti₁₇Cu₁₅, and Fe₇₈B_8.5Si₉P_4.5 alloys upon severe plastic deformation (SPD) has been studied. It is shown that the crystalline to amorphous transition is determined by the ability of the crystals to accumulation of deformation defects under mechanical action, by the thermodynamic stability of the crystalline phases contained in the alloy, and by the possibility of the diffusion processes necessary for the change in the chemical composition of the crystalline and amorphous phases upon deformation. It is found that the susceptibility to amorphization upon SPD does not coincide with the tendency of the alloys to amorphization upon melt quenching