Comprehensive study on filling and solidification process of alloy centrifugal casting

In addition, some researchers also consider the filling flow process and cooling solidification process of liquid metal in the numerical simulation of centrifugal casting, which is closer to the actual situation than studying the filling process or the solidification process alone, but it puts forward higher requirements for computing resources and takes a longer time.

Zagrski used CFD software FLUENT to simulate the centrifugal casting process of aluminum matrix composites. The effects of casting temperature, room temperature, mold speed and mold size, density of matrix phase and reinforcement phase on the structure of the composites were discussed. When using FLUENT software, two-phase flow transient model, VOF model and discrete phase model are used.

Xu and song used finite volume method to simulate the flow and solidification process of molten metal in centrifugal casting process of work roll. The effects of casting position and casting method on temperature field were investigated. The results show that casting at the center position is better than casting at both ends of the mold, and the temperature field obtained by movable casting is more uniform. They used a kind of body fitted grid technology when dividing the grid, which changed the stepped grid at the boundary into a smooth ring grid and improved the calculation accuracy. Their numerical simulation process took 30 s, the focus of the study was only to simulate the liquid metal flow and the temperature change of the outer wall of the mold at the filling stage, and did not consider the solidification process of the casting after the filling.

Kharicha et al. Developed a numerical model based on shallow water equation to simulate the two-dimensional average flow dynamics of liquid metal diffusion filling in horizontal centrifugal casting. In order to consider the centrifugal force, Coriolis force, shear force between molten metal and mold, and gravity, the shallow water equation was improved. In addition, the natural vibration caused by the poor roundness of the mold and bending deformation is also considered in the model.

To sum up, the process of centrifugal casting includes two links: filling and cooling solidification of liquid metal. Researchers at home and abroad have done a lot of work to investigate the centrifugal casting process and optimize the casting process parameters, including numerical simulation and experimental research. In the numerical simulation, different methods are used and many factors are considered, but the research on the mold vibration of centrifugal casting machine is rare. However, in the horizontal centrifugal casting machine, mold vibration has a great influence on the centrifugal casting process and the final product quality, so it is necessary to include this factor into the numerical model.

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