The size-dependent solidification undercooling was investigated for single micro-sized particles of pure Sn employing differential scanning calorimeter(DSC).The particles were obtained from a solvent-encapsulation rem...The size-dependent solidification undercooling was investigated for single micro-sized particles of pure Sn employing differential scanning calorimeter(DSC).The particles were obtained from a solvent-encapsulation remelting and quenching(SERQ) process.Because of the basically unchanged spherical shape of the measured single particles during a series of continuous heating and cooling processes,it allows studying the independent effect of particle size on undercooling.Applying classical nucleation theory in conjunction with available thermodynamic data yields an increasing undercooling with decreasing particle size.The theoretical description is in good agreement with the experimental data.展开更多
The undercooling of the single micro-sized droplet of Sn-3.0Ag-0.5Cu(wt%)alloy has been studied via the newly developed fast calorimetric scanning technique,by which the fast heating and cooling treatment for a single...The undercooling of the single micro-sized droplet of Sn-3.0Ag-0.5Cu(wt%)alloy has been studied via the newly developed fast calorimetric scanning technique,by which the fast heating and cooling treatment for a single droplet can be realized,with the maximum heating or cooling rate being 1×104K/s.Owing to the nearly spherical shape of the single droplet upon heating and cooling and the resul-tant geometric stability,the influence of the droplet size on the solidification process could be elimi-nated.As a result,the puzzled issue on how to separate the mutual effects of droplet size and cooling rate in the field of rapid solidification has been primarily solved,making it possible to study separately the effect of droplet size and cooling rate.Meanwhile,the in-situ observation on deep undercooling could be actualized in this condition,differing from that obtained only by theoretical calculation.The results showed that the undercooling was increased with the increasing cooling rate,and the maximum in-situ measured undercooling reached 116.9K.The undercooling of the single droplet,however,was increased abruptly when cooled at the rate of 2×103K/s.The undercooling increased slightly as the cooling rate was increased continuously to 1×104K/s,implying the infeasibility for gaining large undercooling only by increasing the cooling rate.展开更多
基金supported by the National Natural Science Foundation of China (50971086)Robert Bosch Foundation (32.5.8003.0025.0/MA01)+1 种基金AM Foundation of STCSM (08520740500)EZ acknowledges support from an European Union funded Marie Curie EST fellowship
文摘The size-dependent solidification undercooling was investigated for single micro-sized particles of pure Sn employing differential scanning calorimeter(DSC).The particles were obtained from a solvent-encapsulation remelting and quenching(SERQ) process.Because of the basically unchanged spherical shape of the measured single particles during a series of continuous heating and cooling processes,it allows studying the independent effect of particle size on undercooling.Applying classical nucleation theory in conjunction with available thermodynamic data yields an increasing undercooling with decreasing particle size.The theoretical description is in good agreement with the experimental data.
基金Supported by the Robert Bosch Foundation(Grant No.32.5.8003.0025.0/MA01)the National Natural Science Foundation of China(Grant No.50571057)+1 种基金the National High-Tech Research and Development Program of China("863" Project)(Grant No. 2006AA03Z339)the Shanghai Rising-Star Program(Grant No.06QA14020)
文摘The undercooling of the single micro-sized droplet of Sn-3.0Ag-0.5Cu(wt%)alloy has been studied via the newly developed fast calorimetric scanning technique,by which the fast heating and cooling treatment for a single droplet can be realized,with the maximum heating or cooling rate being 1×104K/s.Owing to the nearly spherical shape of the single droplet upon heating and cooling and the resul-tant geometric stability,the influence of the droplet size on the solidification process could be elimi-nated.As a result,the puzzled issue on how to separate the mutual effects of droplet size and cooling rate in the field of rapid solidification has been primarily solved,making it possible to study separately the effect of droplet size and cooling rate.Meanwhile,the in-situ observation on deep undercooling could be actualized in this condition,differing from that obtained only by theoretical calculation.The results showed that the undercooling was increased with the increasing cooling rate,and the maximum in-situ measured undercooling reached 116.9K.The undercooling of the single droplet,however,was increased abruptly when cooled at the rate of 2×103K/s.The undercooling increased slightly as the cooling rate was increased continuously to 1×104K/s,implying the infeasibility for gaining large undercooling only by increasing the cooling rate.
