Study on mechanism of hydrogen embrittlement through a use of characteristic strength properties of submicron materials

2015 Fiscal Year Final Research Report

• Project/Area Number: 25709003
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Materials/Mechanics of materials
• Research Institution: Kansai University
• Principal Investigator: TAKAHASHI Yoshimasa 関西大学, システム理工学部, 准教授 (20611122)
• Research Collaborator: TANAKA Nobuo 名古屋大学, 未来材料システム研究所, 教授 (40126876) ; MUTO Shunsuke 名古屋大学, 未来材料システム研究所, 教授 (20209985) ; KONDO Hikaru 関西大学, 大学院理工学研究科, 博士前期課程学生 ; AIHARA Kazuya 関西大学, 大学院理工学研究科, 博士前期課程学生 ; ASANO Ryo 関西大学, 大学院理工学研究科, 博士前期課程学生 ; ASHIDA Itaru 関西大学, 大学院理工学研究科, 博士前期課程学生
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 水素脆性 / 格子脆化説 / サブミクロン材料 / 電子顕微鏡 / 強度評価

Outline of Final Research Achievements

The hydrogen-enhanced decohesion (HEDE) theory, which is claimed to be one of the fundamental mechanisms of the so-called hydrogen embrittlement (HE), is experimentally investigated by utilizing the characteristic mechanical properties of submicron-scale materials (e.g. high yield strength, low dislocation density). Submicron specimens are fabricated from (i) a grain boundary (GB) in a polycrystal and (ii) a thin-film layered material. They are fractured either along the GB or interface in a transmission electron microscope (TEM) equipped with an environmental cell. Brittle GB fracture, which is also accompanied by plasticity, is observed only in a hydrogen environment. The strength against interfacial fracture is eminently reduced in a hydrogen environment. These results strongly suggest that the HEDE and its influence on fracture are present regardless of the material scale.

Free Research Field

材料力学