Self-organization of helium precipitates into elongated channels within metal nanolayers

Abstract

Helium bubbles in metals spontaneously form networks of interconnected channels.

Plasma Facing Material by Self-Interstitial Solid Solution Strengthening – Problem, Proposition, and a Solution

“…In physical chemistry sense, He atoms have strong repulsion to W atoms [80,92]. This ultra-low solubility forces He atoms to self-precipitate into small He bubbles [83] that become nucleation sites [90] for further void growth [93] under radiation induced vacancy supersaturations [94], resulting in material swelling [69,86,95] and high temperature He embrittlement [71,96,97], as well as surface blistering [75][76][77][78] under low energy and high flux He bombardment [54,98] at elevated temperatures [99]. This may be mitigated by engineering structures in material which help in outgassing of He.…”

“…ability to contain plasma by inverse or re-radiation due to excellent surface finish), mechanical and aforementioned properties. It is hypothesized that production of surface nanostructure (nanochannels) [83][84][85][86] will help escape of He [60,[87][88][89][90][91] inhibiting formation (nucleation and growth (crystallography) [90] or precipitation and coalescence (physical chemistry)) of bubble and restricts surface degradation. However, this is poorly understood and wrongfully approached.…”

Mechanical behavior of nanocomposites

“…Thermal and irradiation stability, high-temperature strength 22,24,[28][29][30][31] Interfaces with location-dependent energies for interstitials Nanoscale confinement of helium precipitates at misfit dislocation intersections Helium management and outgassing in structural materials for nuclear energy 32,33 Ordered atomic-scale interfacial defect structure to influence deformation twin or glide dislocation nucleation barriers…”

“…Recent works have also explored fatigue and wear resistance, 26,27 and high-temperature strength and radiation behavior. [28][29][30][31][32][33] The defect structure of interphase boundaries at the atomic scale has been shown to correlate with nucleation of glide dislocations and deformation twinning that is relevant to controlling the "twinnability" of interfaces under shock 34 and severe plastic deformation. 25,35 Finally, the morphology of the interfaces in nanocomposites has been shown to be effective in controlling plastic deformability-bicontinuous, intertwined nanocomposites seem to suppress shear localization better than nanolaminates, 36 and hierarchical morphologies can lead to plastic co-deformability in nanocomposites with soft/ hard phases.…”

9R phase enabled superior radiation stability of nanotwinned Cu alloys via in situ radiation at elevated temperature

“…Energetic particle irradiation of metallic materials produces large amounts of point defects (interstitials and vacancies), which can further aggregate into extended defect clusters in the form of dislocation loops [1][2][3][4][5], stacking fault tetrahedrons (SFTs) [6][7][8][9][10][11] or cavities [12][13][14][15][16][17][18][19][20][21][22][23], resulting in microstructural evolution and degradation of mechanical properties [24][25][26][27][28][29]. It has been proposed that the radiation tolerance of materials can be significantly improved by using defect sinks [30][31][32][33][34][35].…”