Calculate the critical radii of the homogeneous core formed when pure Al and Ni solidify, in terms of m. Assume that AT (subcooling=0.2 Tm).
Calculate the number of atoms in the critical size nucleus for both metals at this subcooling.
+ Metal
Surface Energy J/cm^2 93x10^-7 255x10^-7
Solidification Latent Heat (HJ/cm^-3) -1066 -2660
Melting Temperature Tm (°C) 660 1453
Lattice Constant at 20°C (nm)
Al Ni
0.405 0.352