Research status of interfacial heat transfer coefficient in sand mold casting in China

The study of interfacial heat transfer coefficient in China is relatively late. Inspired by foreign scholars, Hao Weiwei, Chen Jiayu and Liu Baicheng of Tsinghua University began to study it for the first time in 1988. They mainly study the inverse calculation of heat conduction in the solidification process, measure the temperature field data of sand mold castings and designated positions inside the mold through thermocouples, measure the change process of interfacial gap layer between sand mold castings and mold during solidification with displacement sensors, and inverse calculate the interfacial heat transfer coefficient by Beck method.

Zhang Liqiang of Hunan University studied the interfacial heat transfer coefficient between A356 aluminum alloy and copper mold by inverse algorithm. He will inverse the damping coefficient of the process μ、 time step Δ T and convergence error value ∆ TCR are considered at the same time, and the interfacial heat transfer coefficient of A356 aluminum alloy solidified in copper mold is calculated. It is found that there are two peaks in the interfacial heat transfer coefficient during solidification.

Hao Jianhua et al. Studied the heat transfer coefficient of the inner and outer interfaces of A356 annular aluminum alloy sand mold castings during solidification in the metal mold. The results show that the heat transfer coefficient of the outer interface decreases with the increase of cooling time, while the cross-sectional heat transfer coefficient of the inner interface increases with the increase of cooling time.

Zhu Liping and Xie Jinting studied the effects of different mold thickness and interfacial gap in different directions on interfacial heat transfer coefficient. The results show that the thicker the mold thickness is, the smaller the interfacial heat transfer coefficient is. At the same time, the interface heat transfer coefficient at the horizontal gap is much smaller than that at the vertical gap. They also found that even in the same direction, the gap size will change even if the measurement positions of mold and sand mold castings are different, resulting in the change of interfacial heat transfer coefficient, indicating the uneven phenomenon of interfacial gap.

In short, with the rapid development of casting CAE technology, the requirements for CAE technology are increasing day by day. The accuracy and integrity of material thermophysical parameters, initial conditions and boundary conditions determine the accuracy of sand mold casting simulation. Many research teams have carried out a lot of research work on the interface heat transfer coefficient in the boundary of sand mold casting, and have made a lot of research progress, which is of great significance to promote the development of casting CAE Technology in many aspects.

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