Abstract
The stray crystal in the platform region is one of the common main defects in single-crystal superal-loy blades.The simple and effective method to eliminate this defect is urgent to be explored.This work found that the Cusp magnetic field can effectively inhibit the stray-crystal formation in the platform.The tendency of stray-crystal formation decreases as the magnetic-field strength increases at a certain with-drawal rate and temperature-gradient.The suppressing effect decreases as the withdrawal rate or the temperature-gradient increases.Finally,the inhibiting mechanism on the stray-crystal formation from the Cusp magnetic field is proposed based on the experiments and the numerical simulation.The magnetic-field application strengthens the flow velocity and changes the flow structure near the liquid-solid in-terface,and further reduces the radial temperature difference.Accordingly,the secondary dendrites in the heat-conduction undercooled zone expands towards the corner in a faster speed,which reduces the stray-crystal formation in the platform corner.This study provides an effective and simple method for decreasing the stray-crystal formation during the preparation of single-crystal with platform region.
基金项目
National Natural Science Foundation of China(51871142)
Independent Re-search and Development Project of State Key Laboratory of Ad-vanced Special Steel,Shanghai Key Laboratory of (SKLASS2020-Z04)
Science and Technology Commission of Shanghai Municipality(19DZ2270200)
NETL
NSTL
维普
万方数据