A Study on the Relationship between Evaluation of Formabilily and Deformation Modes of a Zr-Based Bulk Amorphous Alloy in an Undercooled Liquid Region

摘要

In the present study, the macroscopic formability of a Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10)Be_(22.5) bulk metallic glass was examined through an extrusion tests in a laboratory scale within undercooled liquid state after rapid heating. From the result of compressive deformation tests, basic processing map based on dynamic materials model (DMM) could be constructed to evaluate feasible forming conditions. The formability determined by macroscopic failure matched a good correspondence with the iso-efficiency contour in processing map. Empirical deformation map providing the boundaries among three different deformation modes could be overlapped the processing map and found to present a proper forming condition. In addition, the effect of specimen size and heating rate on the optimal forming condition of this metallic glass system could be discussed.