Research on foreign casting numerical simulation technology in 1970s

In the 1870s, many researchers from Michigan University led by R.D. pehlke and Marrone simulated the solidification process of “t” and “L” low carbon steel samples and deep barrel copper alloy castings with flange edges. During their research, they used the alternating implicit difference method and saulyev explicit difference method, drew the comparison curve between the measured temperature and the simulated temperature, and obtained the isotherm and isochron of the temperature field.

Since then, they have done a lot of research work in the numerical calculation model, the thermophysical parameters of castings and molds, the formation law of air gap at the casting / mold interface and heat transfer mode, made a detailed evaluation on the numerical calculation method and the description of the principle of casting solidification process, and published many influential papers.

Japanese scholars represented by Dazhong Yixiong and shinyama Yingfu also carried out in-depth and detailed research on the simulation of casting solidification process. They use the direct difference method to simulate the casting. This method not only has relatively clear physical meaning and flexible element division, but also is easy to express the castings with complex shape, which provides a feasible way to three-dimensional.

The prediction of shrinkage cavity and porosity of castings and their causes are deeply studied by Dazhong Yixiong, and several common defect discrimination methods such as isochronous solidification curve method and transmittance gradient method are reasonably reviewed.

Xinshan Yingfu is active in the research on the prediction of shrinkage cavity and porosity position of steel castings. He used the finite difference method to establish a set of discrimination method for shrinkage cavity and porosity of steel castings according to the temperature gradient method and g / R method. The prediction results of this method are consistent with the actual defects. These research results have laid a solid foundation for researchers all over the world to study the numerical simulation of casting solidification process, and set off a worldwide upsurge of numerical simulation of casting solidification process.