To investigate the effects of material combinations and velocity conditions on atomic diffusion behavior near collision interfaces,this study simulates the atomic diffusion behavior near collision interfaces in Cu-Al,...To investigate the effects of material combinations and velocity conditions on atomic diffusion behavior near collision interfaces,this study simulates the atomic diffusion behavior near collision interfaces in Cu-Al,Al-Al and Cu-Cu combinations fabricated through collision welding using molecular dynamic(MD)simulation.The atomic diffusion behaviors are compared between similar metal combinations(Al-Al,Cu-Cu)and dissimilar metal combinations(Al-Cu).By combining the simulation results and classical diffusion theory,the diffusion coefficients for similar and dissimilar metal material combinations under different velocity conditions are obtained.The effects of material combinations and collision velocity on diffusion behaviors are also discussed.The diffusion behaviors of dissimilar material combinations strongly depend on the transverse velocity,whereas those of the similar material combinations are more dependent on the longitudinal velocity.These findings can provide guidance for optimizing welding parameters.展开更多
It is urgent to establish a series of reasonable and general approaches to qualitatively and graphically characterize the four core effects of multi-principal element alloys(MPEAs)based on the inherent site preference...It is urgent to establish a series of reasonable and general approaches to qualitatively and graphically characterize the four core effects of multi-principal element alloys(MPEAs)based on the inherent site preference.In this contribution,a qualitatively and graphically characterizing approach to the diffusion behavior of interstitial nonmetallic atoms diffusing along the neighboring octahedra in MPEAs was explored intensively.For this purpose,the C atom diffusing along the neighboring octahedra in FCC_CoNiV MPEA with(V1.0000)1a(Co0.4445Ni0.4444V0.1111)3c,a constant ordered occupying configuration predicted in our previous paper,was demonstrated in detail.Six distinct diffusion paths along[110],[101],and[011]directions on XY,XZ,and YZ planes of FCC_CoNiV MPEA with forward and backward diffusion directions were explored one by one,respectively.The diffusion energy barrier,diffusion coefficient,diffusion constant,and activation energy were derived by employing first-principles calculations based on density functional theory alongside the Climbing Image Nudged Elastic Band method.Unlike diffusing behavior in pure metallic elements,the non-periodic diffusion energy barrier waves are revealed for the real FCC_CoNiV MPEA structure.The significant variations in the diffusion energy barriers are influenced by the atomic environment,particularly the interaction between V and C atoms,which enhances the localization of electrons and increases the overall diffusion energy barrier.The energy barriers show similar trends along six paths,but significant variations occur across different octahedral sites.展开更多
基金supported by the Scientific Research Project of Hunan Provincial Department of Education(22C0642).
文摘To investigate the effects of material combinations and velocity conditions on atomic diffusion behavior near collision interfaces,this study simulates the atomic diffusion behavior near collision interfaces in Cu-Al,Al-Al and Cu-Cu combinations fabricated through collision welding using molecular dynamic(MD)simulation.The atomic diffusion behaviors are compared between similar metal combinations(Al-Al,Cu-Cu)and dissimilar metal combinations(Al-Cu).By combining the simulation results and classical diffusion theory,the diffusion coefficients for similar and dissimilar metal material combinations under different velocity conditions are obtained.The effects of material combinations and collision velocity on diffusion behaviors are also discussed.The diffusion behaviors of dissimilar material combinations strongly depend on the transverse velocity,whereas those of the similar material combinations are more dependent on the longitudinal velocity.These findings can provide guidance for optimizing welding parameters.
基金supported by the National Natural Science Foundation of China(50971043 and 51171046)the Key Research and Development Program of China(CISRI-21T62450ZD)+1 种基金the Natural Science Foundation of Fujian Province(2014J01176,2018J01754,and 2021J01590)the Student Research and Training Program(SRTP)of Fuzhou University(27297).
文摘It is urgent to establish a series of reasonable and general approaches to qualitatively and graphically characterize the four core effects of multi-principal element alloys(MPEAs)based on the inherent site preference.In this contribution,a qualitatively and graphically characterizing approach to the diffusion behavior of interstitial nonmetallic atoms diffusing along the neighboring octahedra in MPEAs was explored intensively.For this purpose,the C atom diffusing along the neighboring octahedra in FCC_CoNiV MPEA with(V1.0000)1a(Co0.4445Ni0.4444V0.1111)3c,a constant ordered occupying configuration predicted in our previous paper,was demonstrated in detail.Six distinct diffusion paths along[110],[101],and[011]directions on XY,XZ,and YZ planes of FCC_CoNiV MPEA with forward and backward diffusion directions were explored one by one,respectively.The diffusion energy barrier,diffusion coefficient,diffusion constant,and activation energy were derived by employing first-principles calculations based on density functional theory alongside the Climbing Image Nudged Elastic Band method.Unlike diffusing behavior in pure metallic elements,the non-periodic diffusion energy barrier waves are revealed for the real FCC_CoNiV MPEA structure.The significant variations in the diffusion energy barriers are influenced by the atomic environment,particularly the interaction between V and C atoms,which enhances the localization of electrons and increases the overall diffusion energy barrier.The energy barriers show similar trends along six paths,but significant variations occur across different octahedral sites.
