Kyushu University, Motooka 744, 819-0395 Fukuoka, Japan.
Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
Science. 2017 Mar 10;355(6329):1055-1057. doi: 10.1126/science.aal2766.
Fatigue failures create enormous risks for all engineered structures, as well as for human lives, motivating large safety factors in design and, thus, inefficient use of resources. Inspired by the excellent fracture toughness of bone, we explored the fatigue resistance in metastability-assisted multiphase steels. We show here that when steel microstructures are hierarchical and laminated, similar to the substructure of bone, superior crack resistance can be realized. Our results reveal that tuning the interface structure, distribution, and phase stability to simultaneously activate multiple micromechanisms that resist crack propagation is key for the observed leap in mechanical response. The exceptional properties enabled by this strategy provide guidance for all fatigue-resistant alloy design efforts.
疲劳失效给所有工程结构以及人类生命带来了巨大的风险，这促使设计中采用了较大的安全系数，从而导致资源的低效利用。受骨骼优异的抗断裂韧性的启发，我们探索了在亚稳相辅助多相钢中的抗疲劳性。我们在此表明，当钢铁微观结构呈层次状和叠层状，类似于骨骼的子结构时，可以实现卓越的抗裂性。我们的研究结果表明，调整界面结构、分布和相稳定性，以同时激活多种抵抗裂纹扩展的微观机制，是实现力学性能飞跃的关键。这种策略所赋予的优异性能为所有抗疲劳合金的设计工作提供了指导。
