Fatigue property in Ni-based bulk metallic glass

Abstract

Fatigue test was carried out on Ni-based bulk metallic glass (BMG) for which there is still no reports on fatigue strength. Test alloy rods with a diameter of 2 mm were prepared in Ni60Zr20Nb 15Al5 at% systems by copper mold casting method. The tensile strength (σB) was 2.9 GPa. The test specimens were machined to hourglass shape type with a minimum diameter of 0.9 mm. The specimens were tested at a stress ratio of 0.1 and a frequency of 10 Hz. The fatigue limit (σW) and fatigue ratio (σw/ σB) in the Ni-based BMG showed high values of 1.68 GPa and 0.58, respectively. The tendency that the σw increased with increasing the σB in BMGs was indicated in the Ni-based BMG. In addition, the fatigue fracture toughness in the Ni-based BMG showed a high value of 14 MPa-m1/2. © 2011 The Japan Institute of Metals.