title: Crack tip shielding observed with high-resolution transmission electron microscopy.
abstract: The dislocation shielding field at a crack tip was experimentally proven at the atomic scale by measuring the local strain in front of the crack tip using high-resolution transmission electron microscopy (HRTEM) and geometric phase analysis (GPA). Single crystalline (110) silicon wafers were employed. Cracks were introduced using a Vickers indenter at room temperature. The crack tip region was observed using HRTEM followed by strain measurements using GPA. The measured strain field at the crack tip was compressive owing to dislocation shielding, which is in good agreement with the strain field calculated from elastic theory.
authors.affiliation: Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Damar Rastri
authors.initials: DR
authors.lastname: Adhika
authors.affiliation: Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan masaki@zaiko.kyushu-u.ac.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Department of Hydrogen Energy Systems, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Daio
authors.affiliation: Department of Materials Science and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Higashida
keywords: HRTEM; brittle-to-ductile transition; dislocation shielding effect; fracture toughness; geometric phase analysis