Constant-pressure molecular dynamics simulation and the pair analysis technique have been performed to study the microstructural evolution of aluminium during rapid solidification.The microstructure characteristics of...Constant-pressure molecular dynamics simulation and the pair analysis technique have been performed to study the microstructural evolution of aluminium during rapid solidification.The microstructure characteristics of icosahedral ordering increase with decrease of the cooling rate,whereas the microstructure unit characteristics of hep crystalline structure decrease.There are two kinds of microstructure units which are similar to those in the fee crystal containing interstitialcies.These two kinds of microscopic units are nearly independent of the cooling rate.The microscopic structural unit characteristics of fee crystalline structure do not depend on the cooling rate either.These results may help us understand the microstructure of glass and its stability.展开更多
Molecular dynamics simulation is performed to study the cooling rate effects on the resulting crystallization microstructure of bulk liquid copper(homogeneous nucleation).Our studies reveal that mixtures of the metast...Molecular dynamics simulation is performed to study the cooling rate effects on the resulting crystallization microstructure of bulk liquid copper(homogeneous nucleation).Our studies reveal that mixtures of the metastable hcp phase and most-stable fcc phase,in all sorts of proportion and in various forms such as layering and phase separation,can be obtained by controlling the cooling rate.We have also found that,below the glass forming critical cooling rate,the ratio of the number of fcc-type polyhedra to the number of hcp-type polyhedra at 0K decreases with increase of the cooling rate.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.19874067the Foundation of the Chinese Academy of Sciences(Grant No.KJ952-J1-412).
文摘Constant-pressure molecular dynamics simulation and the pair analysis technique have been performed to study the microstructural evolution of aluminium during rapid solidification.The microstructure characteristics of icosahedral ordering increase with decrease of the cooling rate,whereas the microstructure unit characteristics of hep crystalline structure decrease.There are two kinds of microstructure units which are similar to those in the fee crystal containing interstitialcies.These two kinds of microscopic units are nearly independent of the cooling rate.The microscopic structural unit characteristics of fee crystalline structure do not depend on the cooling rate either.These results may help us understand the microstructure of glass and its stability.
基金the National Natural Science Foundation of China under Grant No.19874067the Foundation of the Chinese Academy of Sciences under Grant No.KJ952-J1-412.
文摘Molecular dynamics simulation is performed to study the cooling rate effects on the resulting crystallization microstructure of bulk liquid copper(homogeneous nucleation).Our studies reveal that mixtures of the metastable hcp phase and most-stable fcc phase,in all sorts of proportion and in various forms such as layering and phase separation,can be obtained by controlling the cooling rate.We have also found that,below the glass forming critical cooling rate,the ratio of the number of fcc-type polyhedra to the number of hcp-type polyhedra at 0K decreases with increase of the cooling rate.
