中国有色金属学报(英文版)
中國有色金屬學報(英文版)
중국유색금속학보(영문판)
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
2014年
1期
192-198
,共7页
李希彬%芦凤桂%崔海超%唐新华
李希彬%蘆鳳桂%崔海超%唐新華
리희빈%호봉계%최해초%당신화
脉冲电流%凝固%细化机制%晶核迁移%数值模拟
脈遲電流%凝固%細化機製%晶覈遷移%數值模擬
맥충전류%응고%세화궤제%정핵천이%수치모의
electric current pulse%solidification process%grain refinement mechanism%migration behavior%numerical simulation
建立凝固过程的数学模型来揭示自由晶核的迁移行为。模拟结果表明:在脉冲电流作用下,大多数形成于熔体上表面的晶核将往下迁移并随机分布于 Al 熔体内部,提供更多的形核质点,进而细化凝固组织晶粒。同时,研究在施加脉冲电流(ECP)时晶核尺寸对晶核分布和细化的影响。小尺寸的晶核同周围熔体一同运动,迁移距离较短;而大尺寸的晶核在脉冲电流作用下以较快的速度相对于周围熔体运动,有利于熔体内部晶粒的细化。该研究有利于加深对脉冲电流细化凝固组织机理的认识。
建立凝固過程的數學模型來揭示自由晶覈的遷移行為。模擬結果錶明:在脈遲電流作用下,大多數形成于鎔體上錶麵的晶覈將往下遷移併隨機分佈于 Al 鎔體內部,提供更多的形覈質點,進而細化凝固組織晶粒。同時,研究在施加脈遲電流(ECP)時晶覈呎吋對晶覈分佈和細化的影響。小呎吋的晶覈同週圍鎔體一同運動,遷移距離較短;而大呎吋的晶覈在脈遲電流作用下以較快的速度相對于週圍鎔體運動,有利于鎔體內部晶粒的細化。該研究有利于加深對脈遲電流細化凝固組織機理的認識。
건립응고과정적수학모형래게시자유정핵적천이행위。모의결과표명:재맥충전류작용하,대다수형성우용체상표면적정핵장왕하천이병수궤분포우 Al 용체내부,제공경다적형핵질점,진이세화응고조직정립。동시,연구재시가맥충전류(ECP)시정핵척촌대정핵분포화세화적영향。소척촌적정핵동주위용체일동운동,천이거리교단;이대척촌적정핵재맥충전류작용하이교쾌적속도상대우주위용체운동,유리우용체내부정립적세화。해연구유리우가심대맥충전류세화응고조직궤리적인식。
A mathematical model considering free nuclei was developed to reveal the migration behavior of the free nuclei. Numerical simulation results show that most of the nuclei on the top surface of the melt move downwards and distribute randomly inside the Al melt, which induces more nucleation sites resulting in grain refinement. At the same time, the effect of nuclei size on the nuclei distribution and refinement employing electric current pulse (ECP) was also investigated. The smaller nuclei migrate a short distance with the Al melt at lower speed. But for the larger nuclei, the migration downwards with higher speed benefits the refinement of interior grains of the melt. The research results help to better understand the refinement process and provide a more reasonable explanation of the grain refinement mechanism using ECP.