铝基梯度复合材料凝固过程SiC颗粒运动的温度场-流动场耦合数值模拟及实验研究
Coupling simulation of the solidification of functionally graded materials by centrifugal casting and experimental validation
李婧
点击：2175次 下载：0次
作者单位：重庆大学材料科学与工程学院
中文关键字：离心铸造 梯度功能材料 场耦合 数值模拟
英文关键字：Centrifugal casting; Functional graded material; Temperature-flow field coupling
中文摘要：基于当前离心铸造颗粒增强铝基梯度复合材料流动场的数值模拟技术集中在将基体粘度值考虑为不变的背景下，提出了必须将基体的粘度值考虑为温度的函数这一思想，并结合实验得到温度-粘度近似函数。模拟过程为计算铸件的温度场，然后通过温度-粘度函数计算瞬时粘度，最后带入流动场计算颗粒的分布场。通过该方法分别完成了以ZL104合金和ZL109合金为基体的离心铸造SiC颗粒增强梯度功能材料凝固过程场耦合数值模拟。另外，实际浇注实验，分别得到了以ZL104合金和ZL109合金为基体的SiC颗粒增强零件试样，通过进行试样的颗粒偏聚层厚度和颗粒体积分数的测定，并与定粘度模拟值以及变粘度耦合模拟值在颗粒层厚度、颗粒体积分数等方面的对比分析，证实了场耦合思想与实际凝固过程更具契合性。
英文摘要：Recent numerical research of the flow field of particle-reinforced, aluminum matrix graded materials during centrifugal casting have been conducted assuming a constant matrix viscosity. However, matrix viscosity should be considered as a temperature-dependent variable. Based on the general multiphase model of Gao (2007), we developed a viscosity-temperature function and performed a numerical investigation of the solidification process during centrifugal casting of SiC-reinforced, aluminum matrix graded materials using the field coupling method. The method determines the instantaneous temperature field at the beginning of each time step, computes the viscosity field using a viscosity-temperature function and derives the instantaneous flow field. The coupling model predictions of the particle volume fraction distribution during solidification are validated with experimental data.