Numerical simulation of dendritic growth during directional solidification considering peritectic phase

In the present paper, numerical models for microstructure evolution during directional solidification process of Ti-Al alloy were developed on the basis of modified cellular automaton (MCA) method, which took into account the peritectic reaction and peritectic transformation. The models were applied to the simulation of the formation of petitectic phase and the competitive growth of columnar dendrites with different preferred growth orientation during directional solidification process of Ti-47A1 (atomic fraction, %) alloy using liquid metal cooling (LMC) method. Simulations of microstructure evolution during directional solidification were performed at the thermal gradient of 40 K/cm and 80 K/cm, and simulated results were compared with corresponding experiments of Ti-47Al-2Cr-2Nb. Simulated and experimental results show that columnar grains were well aligned along the growth direction from the bottom up to the upper part of the ingot at 80 K/cm, and compared with columnar grains obtained at the thermal gradient of 40 K/cm, the primary dendrite arm spacing decreased.