(1. 吉林大學(xué) 材料科學(xué)與工程學(xué)院， 長春 130025;
2. 吉林大學(xué) 地面機(jī)械仿生技術(shù)教育部重點(diǎn)實(shí)驗(yàn)室， 長春 130025)
摘 要: 建立了金屬液中第二相粒子在離心加速條件下的運(yùn)動(dòng)規(guī)律理論模型，并根據(jù)該理論模型分析了金屬液中第二相粒子的相互作用規(guī)律。結(jié)果表明：在離心加速場(chǎng)中粒子一直處于加速狀態(tài)，不會(huì)達(dá)到勻速運(yùn)動(dòng)狀態(tài)；粒子直徑越大、密度越大，在同樣時(shí)間內(nèi)，粒子移動(dòng)的距離越遠(yuǎn)；在傳輸過程中，不但有因尺寸不同引起的粒子追逐現(xiàn)象，而且有因密度不同引起的追逐現(xiàn)象，該現(xiàn)象是引起粒子碰撞、聚集及尺寸大(或密度大)粒子偏聚到試樣外側(cè)的主要原因。徑向上初始位置不同的兩個(gè)粒子，其間距隨時(shí)間延長逐漸增大。如果在徑向一條直線上有多個(gè)同間距的粒子，離心移動(dòng)一段時(shí)間后，雖然任意兩相鄰粒子的間距比開始態(tài)增大，但各相鄰粒子間距在新的時(shí)刻仍是相等的。
關(guān)鍵字: 離心加速場(chǎng)； 梯度功能材料； 粒子； 理論模型；兩相流
（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
