Effects of Changes in Chemistry on Flex Bending Fatigue Behavior of Al-Based Amorphous Alloy Ribbons

摘要

The effects of changes in composition on the flow behavior and flex bending fatigue behavior of a series of Al-Gd-Ni-Z (X = Fe or Co) amorphous alloy ribbons have been determined at 1 Hz at room temperature. It has been shown that the addition of Fe, Co, and Fe/Co combination into these materials increases the strength, T_g, and T_(x1) in addition to the activation energy for crystallization. The lowest strength (i.e., 880 MPa) base alloy Al_(87)Gd_6Ni_7 exhibited the best low-cycle fatigue (LCF) and worst high-cycle fatigue (HCF) behavior, whereas the higher strength alloys (-1100 MPa) Al_(85)Gd_6Ni_7Fe_2 and Al_(85)Gd_6Ni_7Fe_1Co_1 exhibited worse LCF and better HCF behavior. The ratio of the stress amplitude at the fatigue limit at 1 x 106 cycles to uniaxial failure strength ranged from 0.25 to 0.37 (240 to 397 MPa), much higher than conventional aluminum alloys. These results are also compared with those obtained on other amorphous alloy ribbons.