Computer Simulation of 3-D Random Distribution of Short Fibers in Metal Matrix Composite Materials

In this paper, the microstructure of “Saffil”-Al₂O₃ short fiber reinforced Al-Mg5.5 metal matrix composite material is simulated by computer. In the simulation it is taken into account of that the lengths, diameters, orientations, and locations of short fibers, etc. For the 3-D randomly distributed short fibers in composite materials, the typical distributions of short fiber microstructures on different planes are obtained for different short fiber volume fractions. The microstructural effects of average fiber length, diameter and their standard deviations on the overall strength of metal matrix composite materials are analyzed. From the short fiber microstructural distribution in metal matrix composite materials, the short fiber diameter coefficient ξ_d and short fiber length coefficient ξ₁ are obtained for different standard deviations σ_d and σ_l, respectively. The short fiber orientation coefficient ξ_a is obtained, also. The results of these coefficients may be useful to the manufacture and use of short fiber reinforced composite materials. Considering these coefficients ξ_a ξ_d and ξ_l, the improved formula is given for the direct calculation of overall strength of short fibers reinforced composite materials. The improved formula may reflect the microstructural characteristics of short fibers reinforced composite materials.