摘要
以水冷铜模金属型重力铸造的方法,制备细晶Al-7%Si和Al-17%Si合金,利用ProCAST模拟凝固过程冷却曲线,并通过实测二次枝晶臂间距(SDAS)计算铸件局部冷却速度,结合微观组织形貌分析,研究了冷却速度对初晶硅及共晶硅组织的细化效果。结果表明:模拟的冷却曲线与实测二次枝晶臂间距对应的铸件局部冷却速度变化趋势相符,平均冷却速度属于亚快速凝固范围,随着冷却速度的提高初生相组织越细小,比共晶组织的细化效果更明显。通过实验与计算机模拟相结合更准确地了解冷却速度与铸件组织的关系,为进一步调整浇注工艺优化模具设计从而提高铸件组织性能提供了可行的方案。
This article with the purpose of making fine-grained A1-7%Si and Al-17%Si alloy investigated the relations between the structure morphology and cooling rate. Cooling curves were simulated with the help of finite element analyze software ProCAST and sub-cooling rates are calculated by the actual SDAS values. The results show that these simulated curves are well in agreement with the actual SDAS values obtained from experiments. Furthermore, the average cooling rate during the solidification process is in the range of sub-rapid solidification and the faster cooling rate, the shorter dendrite arm, the better refinement effects. However, the refinement effects on primary phrase are better than that on eutectic silicon. Through experiments combined with the computer simulation more accurate relations between cooling rate and casting conditions are clear, which also provides a possible pattern to improve the alloy microstructure and properties with optimizing the design of casting mould.
出处
《铸造》
CAS
CSCD
北大核心
2013年第10期973-978,共6页
Foundry
基金
国家自然科学基金青年科学基金项目(51201071)
