|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Fatigue in Materials: Fundamentals, Multiscale Modeling and Prevention
||3-D Understanding of Fatigue Crack Initiation from Inclusions in Inconel 718 Alloy
||Pei Cai, Yan Jin, Alfonso H.W. Ngan, Tongguang Zhai
|On-Site Speaker (Planned)
Four-point bend fatigue was conducted on Inconel 718 at room temperature, R=0.1 and 20 Hz in air. Multi-site initiation of fatigue cracks was observed at carbide particles, Ti(C,N) and Nb(C,N). The crack initiation rate was found to be a Weibull function of the applied stress. Nb(C,N) particles formed more than 80% of all the particles and presented a tendency to form clusters. Micro-cross sectioning by focused ion beam (FIB) revealed that thicker Nb(C,N) particles in the surface were more likely to be associated with fatigue crack initiation. It was also found that those crack initiating particles often contained micro-pores. By taking into account the effects of micro-pores and particle thickness, crack initiation at the particles was simulated quantitatively using a recently developed microstructure-base model for short fatigue crack growth. The results obtained were consistent with the experimental observation of the crack initiation behaviors in Inconel 718 alloy.
||Planned: Supplemental Proceedings volume