Rotating-beam fatigue properties and effect of Ni element additive in bulk glassy Zr50CU40Al10 alloys

We examined Wohler curves of Zr50Cu40Al10 and Zr50Cu30Ni10Al10 bulk glassy alloys using a. rotating-beam fatigue test to evaluate the effect of adding a Ni element on fatigue strength. As a result, we found that the fatigue limit was increased from 250 Mpa to 500 MPa by adding 10 at% Ni instead of Cu to a Zr50Cu40Al10 bulk glassy alloy. A Zr50Cu40Al10 bulk glassy alloy exhibits a wide fatigue-fractured region With striation-like marks up to 80% in response to low applied stress (near the fatigue limit). However, adding Ni limits the fatigue-fractured region to half of the whole fractured surface. We also observed fatigue-fmcture surfaces OfZr(50)Cu(40)Al(10) and Zr50Cu30Ni10Al10 bulk glassy alloys to estimate the fatigue-fracture toughness. The fatigue fracture toughness decreases suddenly around N = 10(3) to 10(4), similar to Wohler curves.