Hemispherical bubbles growth on electrochemically charged aluminum with hydrogen

Rozenak, P.

doi:10.1016/j.ijhydene.2007.01.009

Cited by 18 publications

(11 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hydrogen (H) bubble formation, and the consequent hydrogen embrittlement it often results, posts a great threat to the structural integrity and mechanical properties of metals, promoting extensive studies of it over the years. [1][2][3][4] Several mechanisms, including "loop punching" and "vacancy clustering", have been proposed to explain the hydrogen bubble growth. [4] While these mechanisms are quite distinct in nature, they all require a nucleation process for the respective hydrogen bubble growth to occur.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen bubble nucleation by self-clustering: density functional theory and statistical model studies using tungsten as a model system

Hou¹,

Kong²,

Sun³

et al. 2018

Nucl. Fusion

View full text Add to dashboard Cite

Low-energy hydrogen irradiation is known to induce bubble formation in tungsten, while its atomistic mechanisms remain little understood. Using first-principles calculations and statistical models, we studied the self-clustering behavior of hydrogen in tungsten. Unlike previous speculations that hydrogen self-clusters are energetically unstable owing to the general repulsion between two hydrogens, we demonstrated that hydrogen self-cluster becomes more favorable as the cluster size increases. We found that hydrogen atoms would form two-dimensional platelet-like structures along {100} planes. These hydrogen self-clustering behaviors can be quantitative understood by the competition between long-ranged elastic attraction and local electronic repulsion. Further statistical analysis showed that there exists a critical hydrogen concentration above which hydrogen self-clusters are thermodynamically stable and kinetically feasible. Based on this critical hydrogen concentration, the plasma loading conditions under which hydrogen self-clusters form were predicted. Our predictions showed excellent agreement with experimental results of hydrogen bubble formation in tungsten exposed to low-energy hydrogen irradiation. Finally, we proposed a possible mechanism for the hydrogen bubble nucleation via hydrogen self-clustering. This work provides mechanistic insights and quantitative models towards understanding of plasma-induced hydrogen bubble formation in plasma-facing tungsten.

show abstract

Section: Introductionmentioning

confidence: 99%

Hydrogen bubble nucleation by self-clustering: density functional theory and statistical model studies using tungsten as a model system

Hou¹,

Kong²,

Sun³

et al. 2018

Nucl. Fusion

View full text Add to dashboard Cite

show abstract

“…There are few works in the literature studying the effects of hydrogen on metal surfaces, but bubble formation (blisters) was studied in detail in aluminum layers in [28]. Despite the different materials, we think the mechanism described can be adapted also to devices tested in this work, constituted by gold and Al/Ti/Al alloy layers.…”

Section: Discussionmentioning

confidence: 91%

Accelerated testing of RF-MEMS contact degradation through radiation sources

Tazzoli

Barbato

Giliberto

et al. 2010

2010 IEEE International Reliability Physics Symposium

View full text Add to dashboard Cite

This work aims to propose a novel method to\ud accelerate the lifetime of ohmic RF-MEMS switches by means of radiation exposure. Experimental results of proton and γ-ray irradiation were compared to cycling stresses, obtaining similar\ud degradation in electrical performances. Electrical measurements,\ud RF simulations, and AFM analysis of surface roughness were\ud carried out to verify the proposed method

show abstract

“…Various kinds of treatments have been found to be able to introduce cavity, bubbles or blisters in different metals, such as high energy/high dose proton implantation, quenching in H2/H2O gas, and cathodic reaction [1,3,4]. However, the initiation of cavity, dynamic evolution of bubbles/blisters, and how the mechanical properties of metals decay are still not well understood.…”

mentioning

confidence: 99%

In situ S/TEM Observation of Hydrogen Bubbles Formation and Evolution in Aluminium Nanoparticles

Liu

Zhu²

2017

Microsc Microanal

View full text Add to dashboard Cite

The formation of voids and successive growth of hydrogen bubbles in solid metals have attracted extensive attention, mainly because the existence of such bubbles and/or blisters can significantly deteriorate the mechanical properties of the host metals [1,2]. Various kinds of treatments have been found to be able to introduce cavity, bubbles or blisters in different metals, such as high energy/high dose proton implantation, quenching in H2/H2O gas, and cathodic reaction [1,3,4]. However, the initiation of cavity, dynamic evolution of bubbles/blisters, and how the mechanical properties of metals decay are still not well understood. In this work, we employ in situ environmental scanning/transmission electron microscopy (S/TEM) experiments to investigate the formation and evolution of hydrogen bubbles in Aluminium (Al) nanoparticles (NPs) dynamically.The in situ experiments were carried out in Protochips Atmosphere TM TEM environmental gas cell in a probe aberration corrected FEI Titan G2 60-300 kV S/TEM operated under 200 keV. High purity 5% H2 (with balancing gas Ar) was introduced into the cell as hydrogen source. The gas pressure in the environmental cell could be controlled from 1 Torr to 700 Torr by using Atmosphere TM manifold. Under the irradiation from high energy electron beam, hydrogen molecules were ionized to generate atomic H to facilitate its entrance through the surface native Al2O3 layer on Al NPs. Once the cavity at the interface of Al2O3 shell and Al core has nucleated, hydrogen gas bubbles grow by absorbing more hydrogen atoms, which is very similar with the hydrogen bubbles formation in Al pillar as reported in ref [5]. Figure 1 shows the STEM high-angle annular dark-field (HAADF) images from a cluster of Al NPs before and after exposure to hydrogen environment, indicating the formation of hydrogen bubbles at the Al2O3/Al interface. This phenomenon is also confirmed in the bright field TEM imaging, as shown in Figure 2a. After continuing beam irradiation on Al NPs in hydrogen environment, the size of hydrogen bubbles keep increasing and the neighbouring bubbles merge to bigger bubbles. Moreover, the Al core starts to become porosity, as shown in Figure 2b. The generation of porosity inside solid Al core can be attributed to the formation of H-vacancies clusters, and the aggregation of these clusters to form pores inside the solid Al. The effects of beam intensity, hydrogen pressure, and size of NPs on the evolution of hydrogen bubbles and porosity will also be discussed.

show abstract

Hemispherical bubbles growth on electrochemically charged aluminum with hydrogen

Cited by 18 publications

References 19 publications

Hydrogen bubble nucleation by self-clustering: density functional theory and statistical model studies using tungsten as a model system

Hydrogen bubble nucleation by self-clustering: density functional theory and statistical model studies using tungsten as a model system

Accelerated testing of RF-MEMS contact degradation through radiation sources

In situ S/TEM Observation of Hydrogen Bubbles Formation and Evolution in Aluminium Nanoparticles

Contact Info

Product

Resources

About