通过对复杂几何形腔PIM充模流动过程的数值模拟，给出了充模流动过程中模腔内粘度的变化和分布情况，分析了模腔内粘度的最终分布与PIM缺陷形成的关系。模拟结果表明，由于模腔接近充满时压力急剧升高构成无梯度压力场，导致模腔内粘度的最终分布复杂。在充模流动中心区域会形成较高粘度的小区域，分析了这些高粘度小区域的形成及其形状大小的变化过程。指出在流动中心区域形成的高粘度小区域可能使PIM充模流动过程产生粉末-粘结剂两相分离和成形坯件中粉末分布不均的现象。
The variations and distributions of viscosity in PIM filling process are given by numerical simulation of PIM filling process for intricate part. The relation between the final distribution of viscosity and the defects in PIM are analyzed. The results of the simulation showed that the pressure in the cavity heightens sharply at the near end of the filling stage, and then the distributions of velocity and viscosity change rapidly accordingly. As a result of these changes, the distribution of viscosity at the end of the filling stage is very complicated. There are some small areas which viscosity is higher than nearby areas’ in the melt flowing central region. And the process of forming the high viscosity areas and the changing of their geometrical shape are studied. It shows that the powder-binder separation or the density gradients in the component may occur during PIM process.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%