The dynamically changing and combining boundary condition in LMC and the microstructure evolution were simulated by a self-developed software Teccast.Macro-micro structure simulation of blade was conducted at different directional solidification process.The results reveal that the narrower mushy zone can be obtained by LMC compared to the mushy zone in HRS

especially in the thick position.Because of larger temperature gradient and less concave mushy zone by LMC

stray grain can be avoided at higher withdrawal rate.To improve the product efficiency of the hollow SX blade

higher withdrawal rate can be adopted within the range limited by thermal stress.