欢迎您！东篱公司
退出
-
申报数据库
-
立项数据库
-
成果数据库
-
项目获奖数据库
中文摘要：
要采用基于溶质扩散控制模型CA方法对Ti44Al合金定向凝固初始阶段变速冷却过程中胞／枝晶转变过程进行了数值模拟．模拟结果表明，在胞／枝转变过程中，存在胞一枝混合生长区，在一些胞晶相邻面无二次枝晶生长．在给定的冷却速率下，枝晶臂间距大于胞晶臂间距；而在过渡区，枝晶间距达到最大．另外，晶核数量对柱状晶间距产生影响，随着植入晶核数量的增加，柱状晶间距非均匀化程度明显减小．出现过渡区的原因与枝晶生长所引起固／液界面前沿成分波动有关．模拟与实验结果吻合较好．
英文摘要：
The CA method based on solute diffusion controlled model was adopted to simulate cell to dendrite transition of Ti44Al alloys at the initial stage of directional solidification with different velocities. The simulation results show that during cell/dendrite transition the mixed structure is composed of cells and dendrites, in which the secondary dendrites are absent at facing surface of some parallel closely spaced dendrites. The dendrite spacing is larger than cellular spacing at a given rate. The colmnnar grain spacing sharply increases to a maximum as solidification advanced to coexistence zone. In addition, the simulation also revealed that the increase in the number of the seeds decreased the non-uniform degree of the colmnnar grain spacing. The main influence factor affecting cell/dendrite transition is slight fluctuations of liquid composition at growth front. The simulation results also are in reasonable agreement with experiment observation at low cooling rate.
同期刊论文项目
同项目期刊论文
Numerical simulation and experimental investigation of two filling methods in vertical centrifugal c
Microstructure and properties of pure titanium processed by equal-channel angular pressing at room t
位置：