(1. 吉林大学 材料科学与工程学院， 长春 130025;
2. 吉林大学 地面机械仿生技术教育部重点实验室， 长春 130025)
摘 要: 建立了金属液中第二相粒子在离心加速条件下的运动规律理论模型，并根据该理论模型分析了金属液中第二相粒子的相互作用规律。结果表明：在离心加速场中粒子一直处于加速状态，不会达到匀速运动状态；粒子直径越大、密度越大，在同样时间内，粒子移动的距离越远；在传输过程中，不但有因尺寸不同引起的粒子追逐现象，而且有因密度不同引起的追逐现象，该现象是引起粒子碰撞、聚集及尺寸大(或密度大)粒子偏聚到试样外侧的主要原因。径向上初始位置不同的两个粒子，其间距随时间延长逐渐增大。如果在径向一条直线上有多个同间距的粒子，离心移动一段时间后，虽然任意两相邻粒子的间距比开始态增大，但各相邻粒子间距在新的时刻仍是相等的。
关键字: 离心加速场； 梯度功能材料； 粒子； 理论模型；两相流
（1. College of Materials Science and Engineering， Jilin University，
Changchun 130025， P.R.China;
2. Education Ministry Key Laboratory for TerrionMachine Bionics Engineering,
Jilin University, Changchun 130025, P.R.China）
Abstract:The theoretical model of movement behavior of second phase particle in metal melt in centrifugal field was set up. The factors affecting the movement behavior of particles were analyzed with this model. The results show that the particles are in the state of accelerated motion， and can not reach the state of equal velocity motion in centrifugal field. The bigger particle diameter， and the bigger particle density， the longer the distance of particle motion will be. The phenomenon that particle runs after particle exists because of not only the difference of particle diameter but also the difference of particle density during the transport， which is the main reason that particles collide and accumulate and big particles or particles with big density segregate to the specimen outside. The distance between two particles whose initial position at radial direction is different increases gradually with time. For some particles whose space length is the same at a radial straight line， the distances between any two near particles are still equal after particles move for a moment though it is longer than that at initial position.
Key words: centrifugal field； functional gradient material； particle； theoretical model； two-phase fluid
