No abstract

No abstract

In order to investigate very high cycle fatigue properties of Zr55Al10Ni5Cu30 bulk amorphous alloy, rotating bending fatigue tests were conducted at room temperature by using 5 different series of Zr55Al10Ni5Cu30 alloy. The differences of material processing conditions are manufacturer, product year, material size and minimum diameter of specimen. Although all specimens fractured from surface, duplex S-N characteristics were observed for each series of the material. Time strength distributions at N=104 for short life region and at N=107 for long life region were well approximated by normal distribution. The entire S-N property accepting the normalized stress amplitude by the time strength at N=104 or N=107 has shown more clearly duplex S-N characteristics. In addition, P-S-N properties were also estimated from the standard deviation of time strength distributions at N=104 or N=107. Based on the observation of fracture surface by scanning electron microscope (SEM), it is confirmed that every fracture surface was consisting of typical three regions such as multi-facet region, stable crack growth region and instantaneous fracture region.