低压铸造下凝固过程缩孔缩松的预测方法研究

摘要

基于铸件铸型的传热学基础,详细研究了低压铸造下铸件缩孔缩松缺陷的形态,考虑到低压铸造补缩具有重力补缩和压力补缩双重性质的规律,以及压力对临界固相率的影响,提出了一种新的预测低压铸造下缩孔缩松预测的方法,并建立了数学模型.该预测技术基于中北大学特种液态成形技术研究中心所开发的EasyCast软件进行研究,并集成到该软件中.最后将模拟结果与实验结果进行对比,显示该模型能够较好地表现低压铸件的缩孔缩松.%According to the theory of heat transfer, a new prediction method of shrinkage and dispersed shrinkage was presented through detailedly analyzing the shape of shrinkage and dispersed shrinkage under low-pressure casting. The rules of the low-pressure casting feeding which is dual-property of both gravity feeding and low pressure feeding were considered, as well as the effect of the pressure on critical solid fraction, and the mathematic model was built. The prediction technology was based on the self-developed EasyCast software. The comparison between the simulated and experimental results show that this prediction technology can truly exhibit the shrinkage and dispersed shrinkage of casting.