In-situ studies and simulation of equiaxed solidification in Al–20Cu alloy

The equiaxed solidification of Al–20Cu alloy under different cooling rates was investigated using in-situ synchrotron X-ray radiography. The results showed that mean grain size increases rapidly at the early stage of solidification, then reaches the final grain size gradually. And the change of final mean grain size with cooling rate follows d = 4132.3 × R ^−0.86. In addition, the evolution of grain size in Al–20Cu alloy was also simulated by ProCAST software. The experimental and simulation results indicated that, in the range of the cooling rate (5.0–7.5 K min⁻¹), the major factor influencing the final grain size is the maximum nucleation density, while the nucleation undercooling has an insignificant effect on the final grain size.