Characterization of Crack Nucleation in Titanium Alloys with Metastable Microstructures

亚稳态钛合金中裂纹形核的表征

• 批准号: 20F40737
• 负责人: 陳 強
• 金额: $ 1.41万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2020
• 资助国家: 日本
• 起止时间: 2020-11-13 至 2023-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-20F40737/
• 关键词: Titanium alloy; Metastable; Electron Beam Welding; Fatigue; Crack nucleation; Slip deformation; Twinning; Recrystallization; Phase transformation; Titanium Alloy; Crack Nucleation

Definitive evidence for the nanostructured process within FGA is provided by a multi-scale characterization of the nanograin orientation, grain rotation, and the lattice strain up to atom scale by utilizing the transmission Kikuchi diffraction (TKD) and aberration-corrected scanning transmission electron microscope. Direct aging treatment can be used to optimize the mechanical properties of the weldment by decomposition of the thermal martensites and precipitation of the nano lamellar alpha structure within the coarse beta grain, thereby enhancing the crack nucleation resistance. Cracking interfaces of the oxidation domain and topmost nanograins facilitate surface degradation, thereby promoting the stress mismatch along the contact area boundary and giving rise to the formation of macrocrack thereafter with the assistance of oxygen pick-up at the crack tip.

FGA内的纳米结构过程的确定证据是通过利用透射kikuchi衍射（TKD）和比较校正的扫描扫描传输电子显微镜的多尺度表征，纳米重点，谷物旋转和晶格应变至原子尺度的晶格。直接老化处理可用于通过热块状的分解来优化焊接的机械性能，以及在粗β晶粒内的纳米层状α结构的沉淀，从而增强裂纹成核的耐药性。氧化结构域和最高纳米的裂纹界面有助于表面降解，从而促进了沿着接触区域边界的应力不匹配，并在裂纹尖端的氧气拾取后促进了麦克罗克（Macrocrack）的形成。

项目成果

Slip-driven and weld pore assisted fatigue crack nucleation in electron beam welded TC17 titanium alloy joint

• DOI: 10.1016/j.ijfatigue.2021.106525
• 发表时间: 2022-01
• 期刊: International Journal of Fatigue
• 影响因子: 6
• 作者: Hanqing Liu;Jun Song;Haomin Wang;Chuanli Yu;Yaohan Du;Chao He;Qingyuan Wang;Qiang Chen

Crack initiation and short crack propagation of friction stir welded TC17 alloy joint

• DOI: 10.1016/j.ijfatigue.2022.107426
• 发表时间: 2022-11
• 期刊: International Journal of Fatigue
• 影响因子: 6
• 作者: Jun Song;Hanqing Liu;J. Cui;Yong-jie Liu;Lang Li;Yao Chen;Qingyuan Wang;Qiang Chen

Sichuan university/Chengdu university(中国)

四川大学/成都大学（中国）

Effects of local microstructure on crack initiation in super martensitic stainless steel under very-high-cycle fatigue

• DOI: 10.1016/j.ijfatigue.2022.107019
• 发表时间: 2022-10-01
• 期刊: INTERNATIONAL JOURNAL OF FATIGUE
• 影响因子: 6
• 作者: Li, Xue;Dai, Yajun;Wang, Qingyuan
• 通讯作者: Wang, Qingyuan

University of Oxford(英国)

牛津大学（英国）