Anisotropic mechanical of the composite alloys: Al-Sn; Al-Bi and Al-Pb determined at macro levels and their relationship with anisotropic microstructural parameters in variable growth rates of solidification is the basis of the current finding. The mechanical parameters are found generating an identical form of Weibull distribution curve with the variation of anisotropic growth. It follows from the physical understanding of the curve that anisotropic microstructural parameters follow the Weibull distribution. Evidentially, there occurs a relationship between mechanical and microstructural parameters. The relationship is critically analyzed in view of the curve which has two cut-off points corresponding to a lower strength limit in the slow and fast growth regions and an upper strength limit in the moderate growth region. The latter is equivalent to the theoretical strength of lamellae, as microstructural parameters obey Gauss distribution, in the absence of any surface flaws which are responsible for the reduced strength. The physical signification to be drawn from the experimental results is that the variation of an anisotropic mechanical property over the entire experimental range of growth velocity, furnishes an evidence of its dependence as linear, nonlinear and linear respectively, in the slow, moderate and fast growth regions of solidification. Moderate super anisotropic growth velocity (~2.90 x 10-7m3s-1) strengthens the microstructural of binary composite phases two to three fold stronger than those resulting in from their respective isotropic growth observed in an icebath (~273 K) and manifold superior to its constituent phases irrespective of growth mode. Growth habits and thermal stability of composite phases are ascertained using SEM and DSC. X-ray diffraction studies affirm composite alloy to be a terminal solidus solution of physically distinct and mechanical separable phases
