Papers by Keyword: Bulk Amorphous Metal

Abstract: In order to investigate the mechanical behavior of newly developed materials such as bulk amorphous metals, it is essential to use small-size specimens. An instrumented impact testing apparatus was devised which could provide a load-displacement curve on subsize Charpy specimens under impact loading without oscillations. The impact fracture behaviors of Zr-based bulk amorphous metals (BAM) were investigated by using the instrumented impact tester using both V-notched and precracked subsize Charpy specimens. It was found that most of the fracture energy absorbed was used in the process of crack initiation through the development of shear bands.

Abstract: The impact fracture behavior of Zr-based bulk metallic glass was investigated by an instrumented impact tester using subsize Charpy specimens. Influences of loading rate and notch shape on the fracture behavior of amorphous Zr-Al-Ni-Cu alloy were examined. As a result, the maximum load and absorbed fracture energy under impact loading were lower than those under quasi-static loading. A large part of the absorbed fracture energy in the Zr-based BMG was consumed in the process for crack initiation and not for crack propagation. In addition, fractographic characteristics of BMGs were investigated. Fractured surfaces under impact loading are smoother than those under quasi-static loading. The absorbed fracture energy appeared differently depending on the appearance of the shear bands developed. It can be found that the fracture energy and fracture toughness of Zr-based BMG are closely related with the extent of shear bands developed during fracture.