The crack initiation and propagation behavior of a third-generation single crystal superal-loy DD33 with V-notches of different orientations([100],[210]and[110])during thermal fatigue tests:sam-ples were hold at different high-temperatures(1000℃,1100℃ and 1200℃ respectively)for 60 s and then quick quenching into water as one cycle,was investigated by OM,SEM and EDS.The results show that the thermal fatigue properties of DD33 show obvious anisotropy tested at different high-temperatures.The initiation and propagation behavior of thermal fatigue cracks in samples with different notch orienta-tions show the dependence of crystallographic orientation.At 1000℃/1100℃/1200℃,the[100]orientated specimens exhibit the best thermal fatigue performance.The thermal fatigue performance of the[210]ori-ented sample is the worst at 1100℃,while the thermal fatigue performance of the[110]oriented sample is the worst at 1000℃ and 1200℃.The thermal stress,oxidation,and the operation of slip systems result in the difference in crack growth rate of samples with different notch orientations.
维普
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