· Metodos de moldeo y materiales ·
Shankargoud Nyamannavar*, M. Ravi and K. Narayan Prabhu*
Regional Research Laboratory, India , *National Institute o f Technology, India
67th World Foundry Congress
In the present work, a comparative study of microstructure evolution in Sr
modified Al-7Si-0.3Mg alloy isothermally held at semi-solid state under
conditions of (i) cooling from liquid state and (ii) partial melting from solid
state to the semi-solid temperature was carried out. The effect of cooling
rate (0.01 to100 K/s ) on the microstructure during solidification of semisolid
alloy is studied. Partial melting of alloy results in the fine and more
spherical solid phase compared to cooling of the same alloy from liquid
state . Chemical modification of the eutectic silicon by Sr addition was
found to remain same for both cooling the melt from liquid as well as
partial melting from solid state, contrary to the reported results . The
morphology of eutectic silicon corresponding to the liquid entrapped in
solid phase is finer compared to that in interconnected liquid channel.
