薄壁件差压铸造的充型特点及影响因素

Characteristics of Filling Process and Factors of Differential-pressure Cast for Thin-wall Castings

以水模拟实验模拟高强韧铝合金大型薄壁件的差压充型过程 ,研究了铸件壁厚、内浇口形状和数量对充型过程流体形态的影响。实验结果表明 ,铸件壁厚对临界加压速度和临界充型速度影响很大 ,铸件壁越薄 ,临界加压速度和临界充型速度也越大 ;内浇口形状和数量对充型平稳性影响不显著。在此基础上 ,对某一大型薄壁舱体件进行了差压铸造浇注工艺设计和差压充型过程数值模拟 ,数值模拟结果说明 ,以水模拟实验提供的工艺参数所制订的差压铸造浇注工艺方案 ,实现了平稳逐层充型 。

Filling process of differential-pressure cast for thin-wall castings of aluminum alloy is simulated with the hydraulic simulation method. The effects on filling fluid pattern was taken by the figure and amount of the ingate and the wall width of castings are researched. It is shown that the wall width of castings has obvious effect on critical pressure increase rate and critical filling rate, the thinner the wall width of castings is, the bigger the critical pressure increase rate and critical filling rate are; but the figure and the amount of the ingate has no obvious effect on the stationarety of filling. On the basis mentioned above, it is carried out that numeric simulation of filling process of differential-pressure cast and the process design of defferential -pressure cast to some large-scale thin-wall cabin-shape parts, and the result showes that are the smooth and stepwise filling,and the project of differential pressure cast is instituted by the process parameters, which is provide by the hydraulic simulation method. It provides the reference for the produce of this kind of castings.