Numerical Simulation Software Development On Three-Dimensional Temperature Field Of Casting Solidification Process

Numerical simulation enables foundrymen to make virtual castings using computer techniques. Research on that metallic melts transforms from liquid to solid state based on heat transfer theory is an important discipline in casting solidification. Numerical simulation of Temperature field is the basis on predicting solidification shrinkage, gas porosity, lack of fill, laps, hot cracks, macrosegregation and micro-segregation. This dissertation implements a software kit that contains mesh generation, temperature field simulation and data visualization technologies. A fast mesh generation method with "Slice Method" to generate regular and irregular veridical hexahedron meshes of casting and mold is developed. There are fewer limitations of hardware and software to operate this simulation. At the same time, it works at a quick rate in most conditions, such as general simple shape and arbitrary figure. This kind of mesh is needed for applying finite difference method for calculating the temperature field during casting solidification. The Searching algorithms which it can draw precise outline of original entity figure have been developed. It is well known that all mesh generation cannot provide the same figure as the original. So searching a more accurate and fast division is the objective of mesh generation research. This paper presented a technique to avoid the odd point, which moving the dividing plane little and restoring the position. A more precise model to calculate casting solidification temperature field has been built. Using the specific heat method and temperature restoring method, temperature field of two-phase alloy can be simulated more precisely. Visualization of the simulation result was realized. The advanced graphic display technology provides powerful method to observe the simulation data. The fine color graphics can illustrate the solidification result directly and factually. The perfect visualization adds the humanization and convenience of operation. An experiment has been conducted and compared with the simulation result. The experiment is based on the sand mold of Al-Si alloy. From the cooling curve of special point and temperature field of cross-sectional, the comparison is basically satisfactory.