Research on the influence of structure parameters on the fractional shrinkage of wheel shape casting

In the investment casting process, different parts of the casting always have various macroscopic structures. Different distribution of internal stress appears in these different parts in the casting, which let each part have different shrinkage distribution. As the design of die cavity can be based on computer-aided design model and fractional shrinkage in the casting process, it can be of benefit for the die cavity design if the fractional shrinkage can be predicted based on structural parameters of the computer-aided design model. Compared to the traditional die-repair method, it is favorable to achieve fast die-repairing and reduce trial-manufacture cost. As an initial study, a wheel shape casting is designed and it is divided into three parts. Fractional shrinkage of these parts is analyzed to research shrinkage rule. The research methods are casting simulation and experiment. The same process parameters are used in the two methods. The simulated and measured results of fractional shrinkage distribution in the corresponding parts show the same trend. It can be concluded that the simulated result can also reflect the fractional shrinkage distribution effectively. Besides, structural parameters that can influence fractional shrinkage are chosen. Then, the mapping model between these structural parameters and fractional shrinkage is built by regression method. Furthermore, the predicted values of the mapping model are compared with measured values. The result shows that the mapping model has a good performance in predicting fractional shrinkage of different parts in wheel shape casting.