Ultrasonic Fatigue of Ti40Zr10Cu34Pd14Sn2 Glassy Alloy

In this work, ultrasonic fatigue behavior of the Ti40Zr10Cu34Pd14Sn2 glassy alloy was investigated at 20 kHz at a stress ratio of R = −1. The number of cycles to failure in the S-N curve obtained in this work did not decrease again even after 107- 108 cycles unlike previous findings for some steels. The fatigue endurance limit and the fatigue rate were σw = 762 MPa and σw/σB = 0.37, respectively. Fish-eye type inertial crack initiation, reported in many papers on giga-cycle fatigue testing, was not observed. A tendency for the fatigue strength of the Ti40Zr10Cu34Pd14Sn2 glassy alloy specimens to be divided into two groups was observed, that is, specimens with a short fatigue lifetime (<106 cycles) with distinct cast defects as crack initiation sites and the other specimens with a long fati-gue lifetime (>106 cycles). This may have been caused by accidental nucleation of micro-defects such as impurities, voids and precipitates in the glassy rod specimens during the casting