Cyclic Fatigue Fracture of Zr55Al10Ni5Cu30 Bulk Amorphous Alloy with Quenched-in Crystallites

The effects of quenched-in crystallites on the fracture of bulk amorphous alloys under cyclic loading condition were investigated in this paper. For the fully amorphous alloy and specimen with fine crystallites the fatigue crack initiation occurred on the surface. For the specimen with larger crystallites the crack originated from a big broken crystallite near the surface. The average striation spacing on amorphous area is much larger than that on the crystallite. Crack initiation occurred at the crystallites is due to that the brittle crystallites broke easily under cyclic deformation condition. The fine crystallites seemed to be protruded from the amorphous matrix and some bulges appeared on the surface of specimen with fine crystallites under cyclic loading.