Ca simulation of micro structure of directionally solidified DZ125 superalloy

Directionally solidified microstructures of DZ125 superalloy have been simulated by 2D Cellular Automation method, in which the DZ125 multicomponent superalloy is simplified as a pseudobinary alloy. Taking account of continuous nucleation model and dendritic growth kinetics, an array of dendritic microstructures, interface morphology and the variation of primary dendritic arm spacing with the growth rate are obtained and investigated. The simulation results show that the dendritic competitive growth has the characteristic of tip-splitting and annihilation during directional solidification. With the increase of the growth rate, the interface morphologies of DZ125 superalloy change from cellular to dendritic pattern. The primary dendritic arm spacing decreases gradually from 132μm to 55μm as the growth rate increases from 50μm/s to 500μm/s. These simulation results match well with the observations.