期刊
NEW JOURNAL OF PHYSICS
卷 21, 期 -, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/1367-2630/ab1c3b
关键词
atom probe tomography; surface electric field; titanium hydride/deuteride; H/D quantification
资金
- China Scholarship Council (CSC)
- MPG
- Big Max network of the Max Planck Society
- BMBF through the Laplace Project
- [ERC-CoG-SHINE-771602]
Atom probe tomography (APT) has been increasingly used to investigate hydrogen embrittlement in metals due to its unique capacity for direct imaging ofHatoms interacting with microstructural features. The quantitativeness of hydrogen measurements by APT is yet to be established in views of erroneous compositional measurements of bulk hydrides and the influence of spurious hydrogen, e.g. residual gas inside the analysis chamber. Here, we analyzed titanium deuteride (approx. 65.0 at%-66.6 at% D) in lieu of hydride to minimize the overlap with residual gas, both with laser pulsing and high-voltage (HV) pulsing. Strategies were deployed to prevent Hpick-up during specimen fabrication, including preparing specimens at cryogenic temperature. The measured composition of deuterium by APT with laser pulsing decreases significantly with the applied laser pulse energy, which is interpreted with regards to the strength of the corresponding surface electrostatic field, as assessed by the evolution of charge-state ratio. In contrast, compositional analyses withHVpulsing are roughly independent of the applied experimental parameters, although approx. 15 at%-20 at% off the nominal composition. Aided by plotting paired mass-to-charge correlations, the mechanisms of composition bias in both pulsing modes are discussed. A special emphasis is placed on the local variations of the measured composition as a function of the local electric field across the specimen's surface, which is not uniform due to asymmetric heat distribution related to the localized laser absorption and the faceted nature of surface caused by the crystallographic structure. Our investigations demonstrate the challenges of quantitative analysis of solute deuterium by APT but nevertheless provide insight to achieving the best possible experimental protocol.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据