In this paper the relationship between the surface relaxations and the electron density distributions of surface states of Cu（100）, Cu（110）, and Cu（111） surfaces is obtained by first-principles calculations. The...In this paper the relationship between the surface relaxations and the electron density distributions of surface states of Cu（100）, Cu（110）, and Cu（111） surfaces is obtained by first-principles calculations. The calculations indicate that relaxations mainly occur in the layers at which the surface states electrons are localized, and the magnitudes of the multilayer relaxations correspond to the difference of electron density of surface states between adjacent layers. The larger the interlayer relaxation is, the larger the difference of electron density of surface states between two layers is.展开更多
In the present work, the effects of Ni atoms and vacancy concentrations （0.1%, 0.5%, 1.0%） on the formation process of Cu solute clusters are investigated for Fe-1.24%Cu-0.62%Ni alloys by molecular dynamics （MD） s...In the present work, the effects of Ni atoms and vacancy concentrations （0.1%, 0.5%, 1.0%） on the formation process of Cu solute clusters are investigated for Fe-1.24%Cu-0.62%Ni alloys by molecular dynamics （MD） simulations. The presence of Ni is beneficial to the nucleation of Cu precipitates and has little effect on coarsening rate in the later stage of aging. This result is caused by reducing the diffusion coefficient of Cu clusters and the dynamic migration of Ni atoms. Additionally, there are little effects of Ni on Cu precipitates as the vacancy concentration reaches up to 1.0%, thereby explaining the embrittlement for reactor pressure vessel （RPV） steel. As a result, the findings can hopefully provide the important information about the essential mechanism of Cu cluster formation and a better understanding of ageing phenomenon of RPV steel. Furthermore, these original results are analyzed with a simple model of Cu diffusion, which suggests that the same behavior could be observed in Cu-containing alloys.展开更多
基金Project substantially supported by the National Natural Science Foundation of China （Grant No 60471034） and partially by the National Natural Science Foundation of China and the Science Foundation of China Academy of Engineering Physics （Grant No 10576004）.
文摘In this paper the relationship between the surface relaxations and the electron density distributions of surface states of Cu（100）, Cu（110）, and Cu（111） surfaces is obtained by first-principles calculations. The calculations indicate that relaxations mainly occur in the layers at which the surface states electrons are localized, and the magnitudes of the multilayer relaxations correspond to the difference of electron density of surface states between adjacent layers. The larger the interlayer relaxation is, the larger the difference of electron density of surface states between two layers is.
基金supported by the National Natural Science Foundation of China(Grant No.51301102)the Science and Technology Commission of Shanghai Municipality,China(Grant No.15ZR1416000)
文摘In the present work, the effects of Ni atoms and vacancy concentrations （0.1%, 0.5%, 1.0%） on the formation process of Cu solute clusters are investigated for Fe-1.24%Cu-0.62%Ni alloys by molecular dynamics （MD） simulations. The presence of Ni is beneficial to the nucleation of Cu precipitates and has little effect on coarsening rate in the later stage of aging. This result is caused by reducing the diffusion coefficient of Cu clusters and the dynamic migration of Ni atoms. Additionally, there are little effects of Ni on Cu precipitates as the vacancy concentration reaches up to 1.0%, thereby explaining the embrittlement for reactor pressure vessel （RPV） steel. As a result, the findings can hopefully provide the important information about the essential mechanism of Cu cluster formation and a better understanding of ageing phenomenon of RPV steel. Furthermore, these original results are analyzed with a simple model of Cu diffusion, which suggests that the same behavior could be observed in Cu-containing alloys.
