Numerical Simulation of Grain Growth of Directionally Solidified DZ4125 Alloy under Varied Blade Orientations

Abstract

The ProCAST simulation software is used to simulate the temperature field and the mushy zone of the blade under different blade orientations, and then grain growth was investigated based on them. It is found that the temperature field and the mushy zone of the blade samples in the parallel orientation are stably horizontally distributed at the same height, while the perpendicular orientation has a degree of inclination. In the heat preservation zone, the sample temperature close to the furnace wall is higher than that of the sample temperature near the center (referred to here as the Center-Side), and the temperature field is inclined upwards. However, in the cooling zone, the temperature field is inclined downwards because the temperature near the furnace wall (referred to here as the Wall-Side) is lower than that of the Center-Side. The grain growth of the blades with parallel orientation is superior as single crystal blade castings are formed. The blade samples in a perpendicular orientation have a certain heterocrystal tendency. The grain growth of the mutated cross-section of the blade samples is summarized using variable cross-section samples. Heterocrystals are used to be formed at the edge plate of complex structure, the mutation section and the end of spiral crystal separator.

Fig. 9 Schematic diagram of grain growth in the second variable-section platform.