Abstract
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.
Highlights
In the environment of fission/fusion reactors, metallic materials suffer from the bombardment of high energy particles which results in the formation of irradiation-induced defects, such as interstitials, vacancies, dislocation loops, stacking fault tetrahedra (SFTs), etc. [1,2,3]
The mechanical properties of metallic materials could be dramatically degraded by these defects, which is termed as the irradiation effects on mechanical properties including irradiation hardening, embrittlement, creep, and so on [4,5,6]
It can be found that the indentation creep strain decreases with the applied load when the load is less than 15 mN
Summary
In the environment of fission/fusion reactors, metallic materials suffer from the bombardment of high energy particles which results in the formation of irradiation-induced defects, such as interstitials, vacancies, dislocation loops, stacking fault tetrahedra (SFTs), etc. [1,2,3]. In the environment of fission/fusion reactors, metallic materials suffer from the bombardment of high energy particles which results in the formation of irradiation-induced defects, such as interstitials, vacancies, dislocation loops, stacking fault tetrahedra (SFTs), etc. The mechanical properties of metallic materials could be dramatically degraded by these defects, which is termed as the irradiation effects on mechanical properties including irradiation hardening, embrittlement, creep, and so on [4,5,6]. A deep understanding of irradiation effects is vital to the development of advanced structural materials for nuclear reactors. Ion irradiation does have some drawbacks, such as limited penetration depth (several micrometers), and making it quite difficult to characterize mechanical properties of ion irradiated materials through conventional mechanical tests [9,10,11].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
