铸造工艺对铝合金铸件共晶组织的影响

EFFECTS OF CASTING PROCESS ON THE EUTECTIC MICROSTRUCTURE OF ALUMINUM ALLOY CASTING

研究了A356铝合金金属型重力铸造成形试样的微观组织形貌与铸造条件之间的关系,并通过组织分析和冷却速度的计算机模拟,研究了共晶含量与冷却速度之间的关系。结果表明,随着冷却速度的提高,凝固组织中的共晶含量增多,而且初生相组织的形态也由粗大的树枝晶逐步向蔷薇状枝晶演变。通过计算机模拟可较为准确地了解铸件各部位的冷却情况,并为预测铸件不同位置的组织和性能提供参考,为在工业生产中研发形状复杂、要求各异的零件奠定必要的基础。

The relation between the structure aluminum alloy casting was investigated. The quantitative morphology and casting conditions of A356 relation between eutectic content and cooling condition was studied by structure analyzing and computer simulating with different cooling rate. The results showed that with the increasing of cooling rate, the eutectic content in the solidification structure was increased, and the morphology of primary phase developed from coarse dendrite to rosette dendrite. The cooling condition in different positions during casting could be precisely predicted by computer simulation, which could be a kind of reference for the prediction of the microstructure and property in the different locations. These could lay the necessary foundation for the development of casting parts with complex shape and different requirements.