Multiplication process of dislocations at a crack tip revealed by using HVEM tomography.

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H04147
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: Kyushu University
• Principal Investigator: Tanaka Masaki 九州大学, 工学研究院, 准教授 (40452809)
• Co-Investigator(Kenkyū-buntansha): 森川 龍哉 九州大学, 工学研究院, 助教 (00274506) ; 東田 賢二 九州大学, 工学研究院, 教授 (70156561)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 転位 / 破壊 / 亀裂

Outline of Final Research Achievements

The structure of crack tip dislocations in a micro-cantilever specimen were investigated after bending tests. The micro-cantilever was machined in a grain which is in a fully annealed high nitrogen austenitic stainless steel. A notch was introduced at the root of the cantilever by using focused ion beam, then bending load was applied at the edge of the cantilever using s nano-indenter. The state of stress at the notch tip was investigated using finite element method. High-voltage electron microscopy observation revealed dislocation arrays on the slip plane on which the resolved shear stress is the highest, and cross slip of dislocations.

Free Research Field

結晶塑性学