Numerical simulation of microstructure and strength prediction for short-fiber-reinforced metal-matrix composites

作者：Jiang XY^*; Gao Q; Kang GZ

来源：Composites Science and Technology, 1998, 58(10): 1685-1695.

• short-fiber composites
• metal-matrix composites
• microstructure
• strength
• computational simulation

In this paper, the microstructure of a short-fiber-reinforced metal-matrix composite (MMC) material is simulated by computer. The real distribution of short fibers in an Al-Mg5.5 metal-matrix composite is obtained from experimental observation, and the length of ';Saffil'; short Al2O3 fiber in the metal matrix is also obtained. It is found that the distribution of short fibers is approximately 2-D random distribution. Numerical microstructural pictures are compared with experimental SEM photographs. In the simulation, the fiber orientation, fiber diameter, fiber length and fiber location are considered. The microstructural effects of average fiber length and diameter and their distributions on the macroscopic strength of metal-matrix composite materials are analyzed for different fiber volume fractions. The short-fiber orientation coefficient, xi(a), short-fiber diameter coefficient, xi(d), and short-fiber length coefficient, xi(l), are obtained from microstructural distributions of fibres in MMC materials. Considering these coefficients xi(a), xi(d) and xi(l), an improved formula for the macroscopic strength of short-fiber-reinforced composite materials is given. The results from the improved strength formula show good agreement with direct microstructural calculations and experimental values. It is found that the average lengths of short fibers in composite materials may be markedly shortened in the manufacturing process, which may substantially affect the strength of composite materials.

• 出版日期1998
• 单位西南交通大学