材料期刊网

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。

The theoretical model of movement behavior of s econd 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 p a rticles are in the state of accelerated motion， and can not reach the state of e qual velocity motion in centrifugal field. The bigger particle diameter， an d the bigger particle density， the longer the distance of particle motion wil l 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 accu mu late and big particles or particles with big density segregate to the specimen o utside. The distance between two particles whose initial position at r adial direction is different increases gradually with time. For some particles w hose space length is the same at a radial straight line， the distances between a ny two near particles are still equal after particles move for a moment though i t is longer than that at initial position.