Rolling On The Zr-based Amorphous Alloy In The Heating Cheng Zhongjing Dynamics,

Plastic deformation can induce the BMG crystallization as well as heating. In project application, amorphous alloys will occur plastic deformation inevitably. After plastic deformation, microstructure of the alloys will be changed and make an important effect on material property. In this article we take the Zr-base (Zr₆₀Al₁₅Ni₂₅) and (Zr₆₅Al_7.5Ni₁₀Cu_12.5Ag₅) bulk amorphous alloy as the object in our study, by using XRD, DSC to study the effect of rolling deformation on the crystallization kinetics in the thermal process, respectively and discuss the crystallization mechanism in plastic deformation process. Main conclusion as follows:During rolling process in the room temperature, with the distortion increasing, reversible change of atomic configuration has appeared in Zr₆₀Al₁₅Ni₂₅ bulk amorphous alloy and after the rolling its thermal stability reduced. Microstructure change of the Zr₆₀Al₁₅Ni₂₅ caused in rolling process has a main effect on nucleating and growing mechanism in low temperature zones (733K), but almost has no influence on crystallization mechanism in high temperature zones (738K,743K). When the rolling deformation is low(20%), the disorder of configuration in the Zr₆₀Al₁₅Ni₂₅alloys strengthened, which cause the crystallization activation energy increased, and make the crystallization of Zr₆₀Al₁₅Ni₂₅ alloys become quite difficult; On the contrary, the crystallization will become easy. When the rolling deformation is high (90%), due to the appearance of nano crystallization and phase separation, the crystallization activation energy increase substantially.During rolling process in the room temperature, the microstructure of Zr₆₅Al_7.5Ni₁₀Cu_12.5Ag₅) bulk amorphous alloys also has reversible change. When the rolling deformation is very big (95%), massive ordered atom clusters (Icosahedron) formed in the shear bands and near the region. After the plastic deformation, the Arami index (n) is about 1.5².0, which indicate that the rolling deformation almost have no influence on the crystallization mechanism during the heating process. After the rolling, the I phase separates out during the heating process, it is mainly because of the ordered atom clusters which around the shear zone growing up directly in the Zr₆₅Al_7.5Ni₁₀Cu_12.5Ag₅ bulk amorphous alloy. Simultaneously, the crystallization activation energy reduced, it mainly because of the formation of ordered atom clusters around the shear bands, and it is to the benefit of nucleating and I phase growing during rolling deformation. And result in the reduction of crystallization activation energy consequently.