【作者】 曹流； 廖敦明； 胡柏乐； 张影； 孙飞； 陈涛；

【Author】 CAO liu;LIAO Dun-ming;HU Bo-le;ZHANG Ying;SUN Fei;Chen Tao;College of Materials Science and Engineering, Huazhong University of Science and Technology;

【机构】 华中科技大学材料成形及模具技术国家重点实验室；

【摘要】 浇不足是铸造生产中常见的缺陷,目前实验手段只能测量和分析铸件最终的浇不足缺陷分布,难以直接观测浇不足缺陷的形成和演变过程,准确预测浇不足缺陷的关键在于处理凝固过程中流动行为的转变。在已有的处理流动行为转变的基础上,提出一随固相率变化的浇不足缺陷计算模型,即高固相率区采用临界固相率方法,低固相率区采用变粘度方法,中等固相率区采用多孔介质拖拽模型。计算了一组多壁厚铜合金低压铸造工艺,对比分析了模拟和实验铸件充型高度,结果对应较好,证明了所提出的浇不足缺陷计算模型的准确性。更多还原

【Abstract】 Misrun is a common defect in casting production. The current experiment measures can only be used for analyzing the final distribution of misrun defect, the formation process of which is difficult to be observed directly. The key to predict the defect accurately is the way to handle the conversion of flow behavior during the solidification process. On the basis of the existing methods for treating the conversion of flow behavior, a calculation model for misrun defect based on solid-fraction is developed. The critical solid-fraction method is adopted for mushy region with high solid-fraction, the variable viscosity method for mushy region with low solid-fraction, and the porous media drag-based model for mushy region with middle solid-fraction. A set of low pressure die casting crafts with different wall thickness are simulated, and the casting filling height of simulation results coincide with the experiment results, which certifies the accuracy of the adopted model.更多还原