title: Bone-like crack resistance in hierarchical metastable nanolaminate steels.
abstract: 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.
authors.affiliation: Kyushu University, Motooka 744, 819-0395 Fukuoka, Japan. koyama@mech.kyushu-u.ac.jp mm_wang@mit.edu tasan@mit.edu.
authors.forename: Motomichi
authors.identifier: 0000-0002-5006-9976
authors.initials: M
authors.lastname: Koyama
authors.affiliation: Kyushu University, Motooka 744, 819-0395 Fukuoka, Japan.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany. koyama@mech.kyushu-u.ac.jp mm_wang@mit.edu tasan@mit.edu.|Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Meimei
authors.identifier: 0000-0001-8698-2719
authors.initials: M
authors.lastname: Wang
authors.affiliation: Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Ponge
authors.affiliation: Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
authors.forename: Dierk
authors.initials: D
authors.lastname: Raabe
authors.affiliation: Kyushu University, Motooka 744, 819-0395 Fukuoka, Japan.
authors.forename: Kaneaki
authors.initials: K
authors.lastname: Tsuzaki
authors.affiliation: Kyushu University, Motooka 744, 819-0395 Fukuoka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Noguchi
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA. koyama@mech.kyushu-u.ac.jp mm_wang@mit.edu tasan@mit.edu.
authors.forename: Cemal Cem
authors.identifier: 0000-0002-3617-9386
authors.initials: CC
authors.lastname: Tasan