Solidification and microstructure are important indexes to evaluate the mechanical properties
and qualities of casting. Directional solidification describes solidification that occurs from the
farthest end of the casting. This study is devoted to show the directional solidification effect of
copper-aluminum alloy (95%Al,5%Cu) on hardness and microstructure.. This was achieved by
varying the temperature of water flowing from the base in three different temperatures (0,10,20 )ºC
by using a chilling base. It was concluded that the difference in the solidification of the three
samples was due to the different cooling rates applied and as a result of low temperature of
sample, which the chilling base temperature was (0ºC) compared with the rest of the samples
which led to soften the dendrites crystals, and highest hardness reading obtained due to low
temperature of the cooling base of sample.