Structural transformation and rheological processes in
bulk metallic glass Zr41Ti14Cu12.5Ni10Be22.5①
bulk metallic glass Zr41Ti14Cu12.5Ni10Be22.5①
(State Key Lab of Die and Mould Technology, Department of Materials
Science and Engineering,
Huazhong University of Science and Technology, Wuhan 430074, China)
Science and Engineering,
Huazhong University of Science and Technology, Wuhan 430074, China)
Abstract: The temperature dependence of strain and strain rate of the Zr41Ti14Cu12.5Ni10Be22.5 (Vit1) bulk metallic glass (BMG) under constant heating condition was derived from the static extension method with a dynamic thermal mechanical analyzer (DMA). A few strain rate peaks, which corresponds to the glass transition and multistep crystallization in the differential scanning calorimeter (DSC) examination, were observed in the curves of the relation between strain rate and temperature. The onset of viscous flow and the end of glass transition are interrelated, the first and second strain rate peaks correspond with the first and second crystallization transition processes, respectively. The influence of stress on strain and strain rate was researched. It is found that the rheological behaviour of BMG Vit1 changes from elasticity to anelasticity, finally to the Newtonian viscous flow along with increasing temperature.
Key words: bulk metallic glass; glass transition; crystallization; rheological behavior