GLASS-TRANSITION AND VISCOUS-FLOW BEHAVIOR OF AMORPHOUS FE-CR-P, FE-V-P, FE-MO-P ALLOYS

The glass transition and viscous flow behavior of Fe(83-x)M(x)P17 (M = Cr, V or Mo) amorphous alloys was examined using DSC and TMA to clarify the effect of M-substitution on the ideal glass transition temperature (T(gi)), onset temperature of crystallization, viscosity and displacement during a TMA test under an applied stress of 2.5-20 MPa. All the samples exhibit minimum viscosity at the steady state viscous flow temperature. The higher the stress level, the lower the T(gi). The decrease in T(gi) seems to be attributed to a decrease in the free volume and defects in the amorphous alloys. We observed mid-contraction phenomena due to the structural relaxation effected by an external applied stress. The stress level at which the viscous flow occurs increases in the order: chromium, vanadium, molybdenum.