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The consistent symmetry relations computed from the heterogeneous nucleation data of the non-ideal benzoic acid -salicylic acid eutectic system verifies the validity of nucleation theory. The kinetics of crystal growth from the molten state of the system follows the dislocation mechanism. Anomalous behaviour of both viscosity and activation energy for the eutectic melt confirms the essence of specific interactions animating molecular clusters rich in predominating eutectic phase. Micromorphology of the system obeys the HuntJackson model. The plot between a mechanical property and variable anisotropic growth velocity for the eutectic composite evidentially complies with the Weibull probability distribution curve. The curve is perused with 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 aspect reveals the theoretical strength of the eutectic crystallites. The strength-growth relationship explicated thereby is linear, optimum and linear respectively in the slow, moderate and fast growth regions of solidification. The moderate anisotropic growth (~2.96 x 10) is of greater interest by virtue of its attribute to unifying and organizing the crystallites parallel to each other in the growth direction. The eutectic composite material obtained by this process attains remarkable superiority in the mechanical properties over its isotropic growth in an ice bath (~273 K), and its constituent phases. The co-relation between excess thermodynamic functions indeed predicting the liquidus character and the microstructural parameters inevitably structuring the morphology is presented.

The present investigation reveals the relationship between excess thermodynamic functions and the growth habits of the eutectic phases from the melt by continuous melt-growth technique. Excess thermodynamic functions computed for different compositions of the benzoic acid -cinnamic acid eutectic system have been found consistent with the criteria of spontaneity and Planck formulation, and their reliability has been ascertained by the application of Guggenheim lattice theory. The results on the kinetics of anisotropic growth of the eutectic phases from the melt, evidentially evince the dislocation mechanism. Evidences have been obtained for a parabolic variation of mechanical strength with growth velocity of the eutectic material grown anisotropically from the melt at different intervals, which offer supporting complement to the dislocation mechanism governing the dependence of growth velocity on supercooling ∆T in the solidus -liquidus interface in a form : V = k(∆T ) 2 . A moderate anisotropic growth region has been explored by unique results of strength properties and microscopic results as well, to growing a layer of lamellae in a unidirectional lamina. An anisotropic eutectic composite lamellae lamina developed by moderate growth velocity (7.3 x 10 -8 m 3 s -1 ), is of greater interest offering optimum hardness, approximately varying between three-and eight fold average increase in different modes of the mechanical strength in comparison to its isotropic growth carried out in an ice-bath (~273K), and manifold superior to its constituent phases irrespective of the growth mode. The directional lamina of uniform microstructural parameter lamellae, indicates that there is a perfect lamella-matrix equilibrium for which excess thermodynamic functions do vanish.