Microstructural details of hydrogen diffusion and storage in Ti-V-Cr alloys activated through surface and bulk severe plastic deformation
Microstructural details of hydrogen diffusion and storage in Ti-V-Cr alloys activated through surface and bulk severe plastic deformation
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DOI：
10.1016/j.ijhydene.2019.07.058
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发表时间：
2020-02-14
影响因子：
7.2
通讯作者：
Grosdidier, Thierry
中科院分区：
文献类型：
--
作者：
Novelli, Marc;Edalati, Kaveh;Grosdidier, Thierry
采用表面机械磨损处理(SMAT)和高压扭转(HPT)技术，对经表面和体相大塑性变形处理的Ti25V50Cr25和Ti10V75Cr15合金氢化循环后得到的颗粒进行了组织观察。由于氢扩散路径的不同，生成的颗粒在形貌和断裂方式上也不同。具有梯度组织的微细加工样品的断裂模式主要是晶内断裂，而纳米晶HPT加工的样品主要是沿晶断裂。氢从表面晶界开始扩散，形成富钛贫钒区。粉末主要含有β-VH单氢化物和部分伽马-VH2二氢化合物，电子背散射衍射(EBSD)分析表明，两相之间存在(100)(Beta)//(110)(Gamma)和[001](Beta)//[001](Gamma)取向关系，其角偏差接近2.5°。(C)2019氢能出版有限责任公司。爱思唯尔有限公司出版。保留所有权利。
Structural observations were carried out on particles obtained after hydrogenation cycling of the Ti25V50Cr25 and Ti10V75Cr15 alloys processed by surface or bulk severe plastic deformation using the surface mechanical attrition treatment (SMAT) and high-pressure torsion (HPT) techniques, respectively. The produced particles differ in morphologies and fracture mode due to the differences in hydrogen diffusion paths. The fracture mode for the SMAT-processed samples with the gradient microstructure was mainly intragranular, whereas it was intergranular for the nanograined HPT processed samples. Hydrogen diffusion, which initiated at the grain boundaries on the surface, created Ti-rich and V-lean areas. The powders contained mainly beta-VH monohydride and partly gamma-VH2 dihydride, and an orientation relationship of (100)(beta)//(110)(gamma) and [001](beta)//[001](gamma) with an angular deviation of similar to 2.5 degrees was observed between the two phases using the electron backscattered diffraction (EBSD) analysis. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.