The influence of inclusion on high cycle fatigue behavior of an advanced P/M superalloy
The high cycle fatigue (HCF) behavior was investigated in an advanced P/M nickel base superalloy,which was used as aero-engine turbine disc.Load-controlled axial fatigue testing was performed at room temperature (25℃) and 650℃ on specimen taken from a hot isostatic pressing (HIP) disc (Φ180×50 mm).The stress ratio is -1 and 0.1 with test frequency at 140-150Hz.A stress-life (S-N) curve was established where some tests were performed at single stress levels.It is observed that there is some variability in cycles to failure at each stress level,suggesting that different failure mechanisms control the fatigue performance of the separate populations.SEM observations were conducted on fractured surface.It is found that the fatigue cracks initiated mainly from nonmetallic inclusions and then propagated to failure.In addition,the size and the location of inclusions have great influences on HCF lives of the specimens.
Fatigue crack High cycle fatigue Nonmetallic inclusion P/M superalloy S-N curve
Huichen Yu Weibin Guo Ying Li Xueren Wu
Beijing Institute of Aeronautical Materials,Beijing 100095,China
国际会议
成都
英文
279-284
2009-10-16（万方平台首次上网日期，不代表论文的发表时间）