Influence of Rapid Shear-Rate Changes on Microstructure Formation during Semi-Solid Processing
The solidification behavior of the semi-solid slurry with rapid shear-rate changes was investigated by using succinonitrile-5at.%water transparent alloy and Sn-15wt.%Pb alloy on a self-made apparatus. The results showed that the rapid changes of shear-rate improved the nucleation and promoted the globular growth of solidification microstructure in the stirred melt. The increase of shear-rate was in favor of promoting the grain growth with globular shape to a certain extent, however, when the shear-rate was beyond a critical value, the further increase of the shear-rate will lead the disappearance of the globular crystals. Thus, the microstructure of semi-solid processing could be refined by a controlled stirring process.
C.G. Kang, S.K. Kim and S.Y. Lee
X. Lin et al., "Influence of Rapid Shear-Rate Changes on Microstructure Formation during Semi-Solid Processing", Solid State Phenomena, Vols. 116-117, pp. 155-158, 2006