A third-generation synchrotron radiation imaging technique combined with a high-resolution fast-readout CCD(Charge Coupled Device) system was applied to study the dendrite growth of metallic alloy with high resolution images.As one of the first group users of Shanghai Synchrotron Radiation Facility(SSRF)

we acquired a series of animated images of dendrite growth at different cooling rates

using the in-line holography imaging method.At an increased cooling rate

the dendrite grew in an equiaxed manner

the nucleation rate became higher

and the secondary DAS(dendrite arm spacing) reduced greatly.In addition

the formation of microsegregation was affected greatly by the cooling rate.