Microstructure morphologies during the transient solidification of hypomonotectic and monotectic Al–Pb alloys

摘要: Abstract The solidification cooling rate ( T ), growth v temperature gradient G interphase spacing λ ) and diameter d of the Pb-rich phase have been experimentally determined for a hypomonotectic Al–0.9 wt%Pb monotectic Al–1.2 wt%Pb alloys directionally solidified under unsteady-state heat flow conditions. It is shown both cases that, from cooled bottom casting up to certain position along length, microstructure was characterized by well-dispersed droplets in aluminum-rich matrix, followed region morphological transition (with formed fibers) finally mixture fibers strings pearls positions closer top casting. has also observed that such microstructural anticipated alloy with higher solute content. correlation between morphology can be synthesized as follows: alloy,  > 1.0 mm/s  > 1.1 mm/s are proposed.