金属熔体本征过冷度与熔化熵的耦合关系  

Correlations between molar fusion entropy and the intrinsic undercoolability of liquid metals

作　　者：李晨辉[1] 徐明沁[1] 韩秀君[1] 李建国[1] 

机构地区：[1]上海交通大学材料科学与工程学院先进材料凝固实验室,上海200240

出　　处：《上海大学学报（自然科学版）》2015年第1期1-11,共11页Journal of Shanghai University:Natural Science Edition

基　　金：国家重点基础研究发展计划(973计划)资助项目(2011CB012900)

摘　　要：利用气动悬浮和熔融玻璃净化法对液态纯铁的过冷能力进行研究,分别获得了340和281 K的最大过冷度,表明在气动悬浮无容器凝固条件下液态纯铁的形核更接近于均质形核.根据经典形核理论和Spaepen界面能公式,建立了金属熔体本征过冷度(即均质形核对应的过冷度)与熔化熵之间的耦合关系方程.并根据该方程预测了一系列金属熔体的本征过冷度,对比结果表明预测值与实验值具有较好的一致性.High undercoolings up to 340 K and 281 K for pure liquid iron are achieved using aerodynamic containerless levitation and a glass fluxing method, respectively. This implies that the nucleation of liquid iron under aerodynamic containerless solidification condition is closer to homogeneous nucleation. Based on the classical nucleation theory and Spaepen＇s expression for solid/liquid interracial energy, a correlation equation between intrinsic undercooling, namely, the undercooling corresponding to homogeneous nucleation and molar entropy is derived. From this equation, intrinsic undercoolings for a series of liquid metals can be predicted. Good agreement exists between the predicted and experi- mental results.

关 键 词：金属熔体 过冷能力 热物性参数 液固界面能 

分 类 号：TG111.4[金属学及工艺—物理冶金]