Temperature-Time-Transformation Curve and Viscous Flow Deformation of Zr_(55)Cu_(30)Al_(10)Ni_5 Bulk Glassy Alloy

摘要

The temperature-time-transformation curve of a Zr_(55)Cu_(30)Al_(10)Ni_5 bulk glassy alloy was obtained by isothermal DSC measurements. High temperature compression tests were carried out to investigate the viscous flow behavior of the ZR_(55)Cu_(30)Al_(10)Ni_5 bulk glassy alloy. The influence of four process parameters (temperature, time, initial stress, strain rate) on viscous flow deformation of the bulk glassy alloy was studied. X-ray diffractometry (XRD) was used to examine a glassy state of the glassy alloy samples subjected to viscous flow deformation. Appropriate parameters of viscous flow leading to a good deformation process were proposed. The relative displacement over 80 percent was obtained by compressing for 200 s at 723 K. under a pressure of 160 MPa with a strain rate of 1.32 X 10~(-2) s~(-1). The XRD results showed the absence of crystal peaks after viscous flow deformation under the condition being suggested.