With the excellent irradiation resistance due to the chemical complexity,high entropy alloys have attracted considerable attention in the design of nuclear structural materials.However,their performance under successi...With the excellent irradiation resistance due to the chemical complexity,high entropy alloys have attracted considerable attention in the design of nuclear structural materials.However,their performance under successive bombardments remains elusive.In this study,we have investigated the irradiation resistance of equiatomic CoCrCuFeNi HEA compared with Ni metal using molecular dynamics simulations.The evolution of defects such as point defects,defect clusters and dislocations after 400 times of bombardments is examined.The results show that CoCrCuFeNi has fewer point defects than Ni does.Moreover,CoCrCuFeNi has smaller interstitial clusters size,lower interstitial-type Frank partial dislocation density,shorter average interstitial-type Frank partial dislocation length and higher average vacancy formation energy.These findings suggest that CoCrCuFeNi has superior radiation resistance under successive bombardments due to its high entropy effect.展开更多
Tungsten has promising applications in high-radiation,high-erosion and high-impact environments.Laser peening is an effective method to enhance the surface mechanical properties of tungsten materials.However,the ultra...Tungsten has promising applications in high-radiation,high-erosion and high-impact environments.Laser peening is an effective method to enhance the surface mechanical properties of tungsten materials.However,the ultrafast dynamic mechanism of defect evolutions induced by laser shockwave in tungsten lattice is unclear.Here,we investigated the evolutions and interactions of various defects under ultrafast compressive process in tungsten lattice using molecular dynamic method.The results confirm the brittleness of tungsten and reveal that void can reduce the yield strain and strength of the tungsten lattice by accelerating defect mesh extension and promoting the dislocation nucleation around itself.Dislocation density is increased with compressive strain rate.Meanwhile,dislocation multiplication and motion reduce the elastic stage and play a dominant role during the plastic deformation of tungsten lattice.Additionally,void can disrupt the dislocation displacement and promote the pinning effect on dislocations by defect mesh extension.展开更多
基金The work is supported by the Fundamental Research Funds for the Central Universities(No.FRF-IDRY-20-008)Q.Peng acknowledges the support provided by the Deanship of Scientific Research(DSR)at King Fahd University of Petroleum and Minerals(KFUPM)for funding this work through project No.DF201020.
文摘With the excellent irradiation resistance due to the chemical complexity,high entropy alloys have attracted considerable attention in the design of nuclear structural materials.However,their performance under successive bombardments remains elusive.In this study,we have investigated the irradiation resistance of equiatomic CoCrCuFeNi HEA compared with Ni metal using molecular dynamics simulations.The evolution of defects such as point defects,defect clusters and dislocations after 400 times of bombardments is examined.The results show that CoCrCuFeNi has fewer point defects than Ni does.Moreover,CoCrCuFeNi has smaller interstitial clusters size,lower interstitial-type Frank partial dislocation density,shorter average interstitial-type Frank partial dislocation length and higher average vacancy formation energy.These findings suggest that CoCrCuFeNi has superior radiation resistance under successive bombardments due to its high entropy effect.
基金financially support from the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA25040201)the National Natural Science Foundation of China(Grant No.51727901)support provided by the Deanship of Scientific Research(DSR)at King Fahd University of Petroleum&Minerals(KFUPM)(Grant No.DF201020)
文摘Tungsten has promising applications in high-radiation,high-erosion and high-impact environments.Laser peening is an effective method to enhance the surface mechanical properties of tungsten materials.However,the ultrafast dynamic mechanism of defect evolutions induced by laser shockwave in tungsten lattice is unclear.Here,we investigated the evolutions and interactions of various defects under ultrafast compressive process in tungsten lattice using molecular dynamic method.The results confirm the brittleness of tungsten and reveal that void can reduce the yield strain and strength of the tungsten lattice by accelerating defect mesh extension and promoting the dislocation nucleation around itself.Dislocation density is increased with compressive strain rate.Meanwhile,dislocation multiplication and motion reduce the elastic stage and play a dominant role during the plastic deformation of tungsten lattice.Additionally,void can disrupt the dislocation displacement and promote the pinning effect on dislocations by defect mesh extension.
