|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Fatigue in Materials: Fundamentals, Multiscale Modeling and Prevention
||A 3-D Understanding of the Anisotropy in Fatigue Crack Nucleation in an AA7075 T651 Al Alloy Plate
||Yan Jin, Lin Yang, Pei Cai, Jiagang Xu, Wei Sun, Donovan Leonard, Fuqian Yang, Yang-Tse Cheng, Tongguang Zhai
|On-Site Speaker (Planned)
Four-point bend fatigue tests were conducted along L-T, L-S, T-L and T-S planes in an AA7075-T651 plate, respectively, at room temperature, 20 Hz, R=0.1, in air. In L-T and L-S planes, Fe-containing pre-cracked particles were the predominant sites for fatigue crack initiation; whereas, in T-S and T-L planes, Si-bearing particles became the crack nucleation sites. By cross-sectioning these particles using FIB, it was found that thicker particles were more likely to lead to the propagating fatigue cracks, and that those Si-bearing particles that formed cracks were all associated with pores. It was also found that fatigue cracks did not always follow the primary slip planes in the grains where the particles were located, and that Fe-containing particles were protruded on the mechanically polished surface, while Si-bearing particles were intruded, which was consistent with hardness measurements showing that Si-bearing particles were softer than Fe-containing ones in the alloy.
||Planned: Publication Outside of TMS (Indicate publication title and publisher if known.)