Displacement Behavior Study of the Shear Stress Effect on the Early Viscous Flow Nature of Fe-B-Nb-Y Metallic Glassy Powder in Spark Plasma Sintering

Abstract

(Fe_0.72B_0.24Nb_0.04)_95.5Y_4.5 metallic glassy powders were fabricated with a gas-atomizing method and then densely consolidated by the spark plasma sintering (SPS) technique. Densification behavior during the SPS procedure enables us to understand the thermal behavior and viscous deformation profiles of glassy particles. The glassy powders were consolidated under various temperatures to determine the effect of applied stress on the viscous densification behavior. Consequently, viscous densification commenced under a preset stress of 600 MPa at a flow temperature of T_f=663 K, which is approximately 248 K lower than that under a stress of 32 kPa, as shown by thermo-mechanical analysis (TMA). Furthermore, even below T_g, SEM images demonstrated fine imprintability on the glassy powders during this stress-enhanced viscous densification.