Most metals are classified as being either cast or wrought. This classification is somewhat misleading since even the wrought product is initially cast and therefore subject to chemical inhomogenieties during solidification. Dendritic microstructures are common in almost all engineering alloys; a dendritic microstructure for a cast aluminum bronze is shown in Fig. 1.
It should be noted that the alloy can be segregated to either the dendrite core or to the interdendritic regions depending upon the liquidus and solidus lines of the phase diagram (Fig. 2). The first liquid to solidify (center of the dendrite) will be alloy rich if the alloy addition raises the melting temperature, whereas the alloy will be segregated to the interdendritic regions if the alloy addition lowers the melting temperature.