大高径比铸件挤压铸造技术研究

Research on the Squeeze Cast Technology of the Castings with Large Ratio of Height to Thickness

用试验和计算机模拟的方法,研究了高径比为7的铸件凝固过程中的温度分布;研究了铸件中的缩松和铸件力学性能分布特点。结果表明,增加大高径比铸件挤压铸造的比压、提高铸型的预热温度不能有效地减少铸件内的缩松缺陷;采取措施使铸件顺序凝固,并使挤压力有效地作用在液体金属上,可以消除大高径比铸件内的缩松,获得高力学性能的铸件。

In the castings with the ratio of height to thickness being 7, the temperature distribution during solidification was studied by the methods of experiment and computer simulation. And the shrinkage porosity distribution in the castings and the mechanical properties of the castings were also researched. The experimental and simulated results show that increasing squeeze force, or enhancing temperature of the mold cannot reduce the porosities in the castings. When castings solidify as a sequence manner and the squeeze force effectively acts on the surface of the liquid metal, the porosities in the castings are eliminated and mechanical properties are increased.