Calculation of mechanical properties of hypothetic eutectic nanocomposites LaB6-MeB2

This effort is to investigate the possibility of developing new eutectic composite materials based on quasi-binary systems LaB6-MeB2 (Me stands for Ti, Zr, Hf, etc.), where reinforcing fibers of MeB2 are nano-size in cross-section while having a comparatively long generatrix. The composites were assumed to be produced by the method of directed solidification of eutectic melts. A model of morphology showed very close agreement to the technological sample that was obtained by directional solidification. Algorithm of calculation of mechanical properties was based on an asymptotic method of averaging by Bakhvalov-Sanches Palencia [Sanches-Palencia, E., Non-Homogeneous Media and Vibration Theory. Springer-Verglag, New York, 1980; Bakhvalov, N. S. and Panasenko, G. P., Averaging of processes in periodic media. Nauka, Moscow, 1984, [in Russian]]. Geometry of a material (a representative cell) are accepted the same as for eutectic alloys, but a ratio of nano-whisker radius and cell size varies in some limits. The numerical experiment shows considerable increase of values of elastic constants for nanocomposites. Fields of thermo-deformations were calculated both for real eutectic systems LaB6-MeB2 and for hypothetical nanocomposites of these systems with different volume fraction of reinforcing whiskers. The macrocomposite results are in good agreement with its experimental observations, and for nanocomposites, the predicted characteristics are very attractive, which offers a solution for modification of technology of directed solidification of eutectic systems for the case of nano-size whisker reinforcements.