Anomalous Temperature Dependence of Crystalline-to-Amorphous Transformation Induced by High-Pressure Torsion in Zr₅₀(Cu,Al)₅₀

Abstract

Martensite phases of Zr 50 Cu 50 and Zr 50 Cu 44 Al 6 were deformed by high-pressure torsion (HPT) at different temperatures ranging from 253 to 473 K. Microstructural observations revealed that the crystalline-to-amorphous transformation induced by HPT showed remarkable temperature dependence: an increase in deformation temperature up to 473 K significantly increased the fraction of the amorphous structure. This result suggests that the lattice instability near martensitic transformation temperature promotes crystalline-to-amorphous transformation, which is coherent to the generalized Lindemann criterion of defect-induced amorphization.

Characterisation of precipitates formed in high-pressure torsion treated Mg-3.4at.%Zn alloy

“…This load was maintained for 30 s before and during the application of rotational strain at a rotation speed of 1 RPM. Previous studies on a Zr 50 (Cu, Al) 50 alloy under similar deformation conditions found that frictional heating only increased the anvil temperature adjacent to the sample to ∼306 K [12]. The temperature increase for the present material is expected to be significantly less and insufficient to facilitate precipitation during HPT.…”

Pronounced Structural Rejuvenation in Zr₅₀Cu₄₀Al₁₀ Metallic Glass Strained by Torsional Straining at Elevated Temperature

“…Changing HPT conditions, such as rotation speed and deformation temperature, may result in interesting phenonmena. Our previous study reported the proper increasing deformation temperature during HPT processing facilitates the transformation from crystalline to amorphous phase in ZrCuAl alloys, 11) but the effect on the Zr-based BMGs is still not clear. In the present study, the deformation temperature was changed during HPT processing and the thermal behaviors were analysized to quantify the structure change in Zr 50 Cu 40 Al 10 BMG.…”