NUMERICAL SIMULATION OF DIRECTIONAL SOLIDIFICATION OF TURBINE BLADE BY LMC PROCESS

The directional solidified blade castings are wildly used in aero-engines, because the directional solidified microstructure leads to excellent high temperature performance. A very strict process control is needed to avoid stray grains. In recent years, liquid metal cooling (LMC) is used as a new process to manufacture blade castings, and still needs to be improved. The numerical simulation of the LMC process is helpful to optimize the technical parameters and reduce the development cycle and cost. In this paper, a model of a LMC process considering the convection between the shell and the cooling liquid metal was established. Different LMC solidification processes were simulated. The results indicate that higher withdrawing rate or lower cooling liquid metal temperature can obtain higher temperature gradient and lead to thinner mushy zone. However, if the withdrawing rate is too high, the mushy zone becomes concave.