Temperature, strain and strain rate dependence of serrated flow in bulk metallic glasses

被引：24

作者：

Dalla Torre, Florian H.

Dubach, Alban

Nelson, Adrienne

Loeffler, Joerg F.

机构：

[1] ETH, Dept Mat, Lab Met Phys & Technol, CH-8093 Zurich, Switzerland

[2] Univ Cambridge, Dept Mat Sci & Met, Cambridge CB2 3QZ, England

来源：

MATERIALS TRANSACTIONS | 2007年 / 48卷 / 07期

关键词：

bulk metallic glasses; serrated flow; deformation kinetics; shear band relaxation; strain rate sensitivity;

D O I：

10.2320/matertrans.MJ200782

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

New findings on the inhomogeneous plastic deformation of bulk metallic glasses (BMGs) have shown a disappearance of serrated flow below a critical temperature or above a critical strain rate. This correlates with a change in the strain rate sensitivity (SRS) from negative to positive values. suggesting a change in the deformation mechanism. In addition, a change in the SRS correlating with the increase in the stress drop magnitude is observed with increasing strain. Results on the serration and flow dependence for the binary BMG Cu50Zr50 show close phenomenological similarities with the Portevin - Le Chatelier or dynamic strain aging effect known for crystalline solids. An alternative model for the appearance and disappearance of serrated flow based on the structural relaxation of the atomic configuration of shear transformation zones is described.

引用

页码：1774 / 1780

页数：7

共 58 条

[31] Characterization of nanometer-scale defects in metallic glasses by quantitative high-resolution transmission electron microscopy [J].