Novel heating- and deformation-induced phase transitions and mechanical properties for multicomponent Zr50M50, Zr50(M,Ag)50 and Zr50(M,Pd)50 (M = Fe,Co,Ni,Cu) amorphous alloys

Multicomponent alloys of Zr50M50, Zr-50(M,Ag)(50) and Zr-50(M,Pd)(50) (M = Fe,Co,Ni,Cu) can be melt-spun to obtain amorphous ribbons. The maximum thickness for fully amorphous ribbons varies with composi-tion in the range 34-53 mu m. In contrast, fully amorphous ribbons are not obtainable for binary Zr50Ni50 or ternary Zr-50(Ni,Cu)(50) alloys. Heating-induced crystallization occurs through: two stages of amorphous [am] -> [am ' + B2] -> [B2 + B33] for Zr50M50; and [am] -> [ am ' + B2] -> [B2 + AgZr] for Zr-50(M,Ag)(50); and a single stage of [am] -> [B2] for Zr-50(M,Pd)(50), while no B2 phase is formed for the binary and ternary Zr(50)Q(50) (Q = Ni or/and Cu) alloys. As-spun amorphous ribbons have good bending plasticity. Remarkably, Zr50M50 ribbons in tension show 0.22-0.28% plastic elongation and work-hardening (the yield stress is similar to 820 MPa, the fracture stress is similar to 1200 MPa). When cold-rolled at room temperature to 30% reduction in thickness, Zr50M50 ribbons show 10% increase in hardness, while retaining good bending plasticity. Cold-rolling induces precipitation of spheroidal B2 and irregular B33 particles, while deforma-tion in tension induces B2, B33 and also plate-like monoclinic precipitates. The B2 and B33 particles form by polymorphic transformation, and include a high density of internal defects. This novel deformation-induced precipitation has not been recognized for any Zr(50)Q(50) binary or ternary alloys. The new multi-component systems are encouraging for future progress as structural amorphous alloys. (C) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

Multicomponent alloys of Zr50M50, Zr-50(M,Ag)(50), and Zr-50(M,Pd)(50) can be melt-spun to obtain amorphous ribbons with good bending plasticity and tensile properties. Cold-rolling and tension induce precipitation of different phases.