Dendrite growth in nickel-based superalloy with in-situ observation by high temperature confocal laser scanning microscopy and numerical simulation

Abstract Dendrite growth of nickel-based superalloy was investigated by using high temperature confocal laser scanning microscopy (HT-CLSM) and numerical simulation method. The influence of cooling rate on the evolution of dendrite was discussed through in-situ observation experiments and simulation cases. The results indicate that secondary and tertiary dendrites grow luxuriantly at the higher cooling rate and primary dendrite present well growth tendency at the lower cooling rate. The variation of secondary dendrite arm spacing (SDAS) with cooling rate was also analyzed, and the results show that SDAS decrease exponentially with the increasing of cooling rate, which is helpful for designing process parameters to obtain desirable dendrites.