Kang Jinwu, Wang Jiwu, Shangguan Haolong, Zheng Lele, Deng Chengyang, Hu Yongyi, Yi Jihao
School of Materials Science and Engineering, Key Laboratory for Advanced Materials Processing Technology, Tsinghua University, Beijing 100084, China.
School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China.
Materials (Basel). 2020 Mar 31;13(7):1596. doi: 10.3390/ma13071596.
The author-proposed skeletal sand mold, which mainly includes a shell, air cavities and a truss support structure, has been experimentally proven to be very useful in controlling the cooling of casting at local areas and at different periods of the casting process. The modeling and simulation of the casting process using a skeletal sand mold were systemically analyzed. Complicated casting/mold and mold/air boundaries, and the thermal and mechanical behavior of the skeletal sand mold during the casting process were highlighted. A numerical simulation of the casting process of a stress frame specimen using a skeletal sand mold was performed. The temperature, stress and displacement fields of the casting and skeletal sand mold were obtained and compared with those using a traditional sand mold. The simulated results were validated with experiments. Using the skeletal sand mold, the cooling rate of the casting can be greatly improved due to the significant heat release from mold surface to environment. The residual stress and deformation of the casting can be reduced because of the decreased stiffness of this kind of mold. Although the skeletal sand mold is susceptible to cracking, it can be avoided by filleting in the conjunctions and increasing the shell thickness.
作者提出的骨架砂型，主要包括壳体、气孔和桁架支撑结构，已通过实验证明在控制铸件在局部区域以及铸造过程不同阶段的冷却方面非常有用。系统地分析了使用骨架砂型进行铸造过程的建模与模拟。突出了复杂的铸件/铸型和铸型/空气边界，以及铸造过程中骨架砂型的热行为和力学行为。对使用骨架砂型的应力框架试件的铸造过程进行了数值模拟。获得了铸件和骨架砂型的温度、应力和位移场，并与使用传统砂型的情况进行了比较。模拟结果通过实验进行了验证。使用骨架砂型，由于铸型表面向环境的大量散热，铸件的冷却速率可大大提高。由于这种铸型的刚度降低，铸件的残余应力和变形可以减少。尽管骨架砂型容易开裂，但可以通过在连接处倒圆角和增加壳体厚度来避免。
