scholarly journals Fundamental Mechanisms for Irradiation-Hardening and Embrittlement: A Review

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1132 ◽  
Author(s):  
Xiazi Xiao
Keyword(s):  
Material Properties ◽  
Interaction Process ◽  
Experimental Equipment ◽  
General Introduction ◽  
Irradiation Hardening ◽  
Testing Conditions ◽  
Defect Interaction ◽  
Dislocation Defect ◽  
Induced Defects ◽  
Irradiation Induced Defects

It has long been recognized that exposure to irradiation environments could dramatically degrade the mechanical properties of nuclear structural materials, i.e., irradiation-hardening and embrittlement. With the development of numerical simulation capability and advanced experimental equipment, the mysterious veil covering the fundamental mechanisms of irradiation-hardening and embrittlement has been gradually unveiled in recent years. This review intends to offer an overview of the fundamental mechanisms in this field at moderate irradiation conditions. After a general introduction of the phenomena of irradiation-hardening and embrittlement, the formation of irradiation-induced defects is discussed, covering the influence of both irradiation conditions and material properties. Then, the dislocation-defect interaction is addressed, which summarizes the interaction process and strength for various defect types and testing conditions. Moreover, the evolution mechanisms of defects and dislocations are focused on, involving the annihilation of irradiation defects, formation of defect-free channels, and generation of microvoids and cracks. Finally, this review closes with the current comprehension of irradiation-hardening and embrittlement, and aims to help design next-generation irradiation-resistant materials.

scholarly journals Texture evolution and mechanical behaviour of irradiated face-centred cubic metals

2018 ◽  
Vol 474 (2210) ◽  
pp. 20170604 ◽  
Author(s):  
L. R. Chen ◽  
X. Z. Xiao ◽  
L. Yu ◽  
H. J. Chu ◽  
H. L. Duan
Keyword(s):  
Mechanical Behaviour ◽  
Crystallographic Texture ◽  
Texture Evolution ◽  
Polycrystalline Materials ◽  
Irradiation Hardening ◽  
Cubic Metals ◽  
Physically Based ◽  
Induced Defects ◽  
Irradiation Induced Defects ◽  
Good Agreement

A physically based theoretical model is proposed to investigate the mechanical behaviour and crystallographic texture evolution of irradiated face-centred cubic metals. This model is capable of capturing the main features of irradiated polycrystalline materials including irradiation hardening, post-yield softening and plasticity localization. Numerical results show a good agreement with experimental data for both unirradiated and irradiated stress–strain relationships. The study of crystallographic texture reveals that the initial randomly distributed texture of unirradiated metals under tensile loading can evolve into a mixture of [111] and [100] textures. Regarding the irradiated case, crystallographic texture develops in a different way, and an extra part of [110] texture evolves into [100] and [111] textures. Thus, [100] and [111] textures become dominant more quickly compared with those of the unirradiated case for the reason that [100] and [111]-oriented crystals have higher strength, and their plastic deformation behaviours are more active than other oriented crystals. It can be concluded that irradiation-induced defects can affect both the mechanical behaviour and texture evolution of metals, both of which are closely related to irradiation hardening.

scholarly journals Hardening and Creep of Ion Irradiated CLAM Steel by Nanoindentation

Crystals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Ying Liu ◽  
Wenbin Liu ◽  
Long Yu ◽  
Lirong Chen ◽  
Haonan Sui ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Primary Creep ◽  
Steady State Creep ◽  
Indentation Creep ◽  
Metallic Materials ◽  
Irradiation Hardening ◽  
Clam Steel ◽  
Large Numbers ◽  
Induced Defects ◽  
Irradiation Induced Defects

Ion irradiation, combined with nanoindentation, has long been recognized as an effective way to study effects of irradiation on the mechanical properties of metallic materials. In this research, hardening and creep of ion irradiated Chinese low activation martensitic (CLAM) steel are investigated by nanoindentation. Firstly, it is demonstrated that ion irradiation results in the increase of hardness, because irradiation-induced defects impede the glide of dislocations. Secondly, the unirradiated CLAM steel shows indentation creep size effect (ICSE) that the indentation creep strain decreases with the applied load, and ICSE is found to be associated with the variations of geometrical necessary dislocations (GNDs) density. However, ion irradiation results in the alleviation of ICSE due to the irradiation hardening. Thirdly, ion irradiation accelerates nanoindentation creep due to the large numbers of irradiation-induced vacancies whose diffusion controls creep deformation. Meanwhile, owing to the annihilation of vacancies, ion irradiation has a significant influence on the primary creep while only negligible influence has been observed for the steady-state creep.

Irradiation Damage and Embrittlement in RPV Steels Under the Aspect of Long Term Operation: Overview of the FP7 Project LONGLIFE

2010 ◽  
Author(s):  
Eberhard Altstadt ◽  
Frank Bergner ◽  
Hieronymus Hein
Keyword(s):  
Cluster Formation ◽  
Irradiation Damage ◽  
Irradiation Embrittlement ◽  
Irradiation Hardening ◽  
Term Operation ◽  
Weld Material ◽  
Project Structure ◽  
Induced Defects ◽  
Irradiation Induced Defects

The increasing age of the European NPPs and envisaged lifetime extensions up to 80 years require an improved understanding of RPV irradiation embrittlement effects connected with long term operation (LTO). Phenomena which might become important at high neutron fluences (such as late blooming effects and flux effects) must be considered adequately in the safety assessments. Therefore the project LONGLIFE was initiated within the 7th Framework Programme of the European Commission. The project aims at: i) improved knowledge on LTO phenomena relevant for European reactors; ii) assessment of prediction tools, codes, standards and surveillance guidelines. In the paper, we give an overview of the project structure and the related tasks. Furthermore we present two examples for the experimental evidence of LTO relevant phenomena: the first example is related to the flux dependence of defect cluster formation in a neutron irradiated weld material. We have found that the size of the irradiation induced defects exhibits a flux effect whereas the mechanical properties are almost independent of the flux. The second example refers to the acceleration of irradiation hardening after exceeding a threshold fluence. This effect was observed by means of both small angle neutron scattering (SANS) and tensile testing for low Cu RPV steels irradiated at a temperature of 255 °C. These examples demonstrate that LTO irradiation effects have to be investigated in more detail to guarantee the applicability of the embrittlement surveillance guidelines beyond 40 years of operation.

C ions irradiation induced defects analysis and effects on optical properties of TiO2 Nanoparticles

2021 ◽  
Vol 863 ◽  
pp. 158635
Author(s):  
Afsheen Farooq ◽  
Samson O. Aisida ◽  
Abdul Jalil ◽  
Chang-Fu Dee ◽  
Poh Choon Ooi ◽  
...  
Keyword(s):  
Optical Properties ◽  
Tio2 Nanoparticles ◽  
Defects Analysis ◽  
Induced Defects ◽  
Irradiation Induced Defects

Self-annihilation of electron-irradiation-induced defects in InAsxP1−x∕InP multiquantum well solar cells

2007 ◽  
Vol 90 (23) ◽  
pp. 233111 ◽  
Author(s):  
Aurangzeb Khan ◽  
A. Freundlich ◽  
Jihua Gou ◽  
A. Gapud ◽  
M. Imazumi ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electron Irradiation ◽  
Induced Defects ◽  
Irradiation Induced Defects ◽  
Multiquantum Well

Study of Compensation Defects and Electron Irradiation-Induced Defects in Undoped SI-InP by Positron Lifetime Spectroscopy

2008 ◽  
Vol 607 ◽  
pp. 134-136
Author(s):  
Y.J. Zhang ◽  
Ai Hong Deng ◽  
You Wen Zhao ◽  
J. Yu ◽  
X.X. Yu ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Positron Lifetime ◽  
Deep Level ◽  
High Concentration ◽  
Positron Annihilation Lifetime ◽  
Donor Type ◽  
Positron Lifetime Spectroscopy ◽  
Transient Spectroscopy ◽  
Induced Defects ◽  
Irradiation Induced Defects

Positron annihilation lifetime (PAL) spectroscopy，photo-induced current transient spectroscopy (PICTS) and thermally stimulated current (TSC) have been employed to study the formation of compensation defects and their evolvement under iron phosphide (IP) ambience or pure phosphide (PP) ambience. In the formation of IP SI-InP, the diffusion of Fe atoms suppresses the formation of some open-volume defects. As to PP SI-InP, VInH4 complexes dissociate into acceptor vacancies VInHn(n-3)(n=0,1,2,3), which compensate residual donor type defects and make the sample semi-insulating. Electron irradiation-induced deep level defects have been studied by TSC in PP and IP SI-InP, respectively. In contrast to a high concentration of irradiation-induced defects in as-grown and PP annealed InP, IP SI-InP has a very low concentration of defects.

Low temperature annealing of electron irradiation induced defects in 4H-SiC

2004 ◽  
Vol 85 (17) ◽  
pp. 3780-3782 ◽  
Author(s):  
Antonio Castaldini ◽  
Anna Cavallini ◽  
Lorenzo Rigutti ◽  
Filippo Nava
Keyword(s):  
Low Temperature ◽  
Electron Irradiation ◽  
Low Temperature Annealing ◽  
Induced Defects ◽  
Irradiation Induced Defects
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