Computer simulation of particle matrix interactions in silicon carbide reinforced aluminium metal matrix composites.

摘要

The present work aims at understanding particle matrix interactions in SiC reinforced aluminium metal matrix composites (MMCs) by means of computer simulation. Firstly, to explore the basic role of hard particles, the stress field around a spherical SiC particle, the stress and the energy gathering capabilities of particle, interfacial characteristics, and the particle size effect have been examined by applying and extending Eshelbyu27s classic approach. Secondly, a new method has been developed to calculate the inhomogeneity problem with an arbitrary shaped particle. This method combines boundary integral equations with a sequence of cutting, straining, and welding procedures to numerically acquire stress and strain distribution at an inhomogeneity. Thirdly, an elastic-plastic FEA has been used to investigate the plastic behaviour of the matrix (i.e. plastic relaxation and plastic accumulation) and its effect on the stress transfer and the stress concentration. Fourth, the influence of the volume fraction, the particle shape, the particle clustering, the particle size, and thermally induced residual stresses on deformation characteristics of Al/(SiC)$sb{m P}$ MMCs has been studied by using FEA and applying the concept of the Flower-Watt unit cell. Fifth, the ductility of MMCs has been discussed. It has been found that the major distinctions between MMCs and unreinforced alloys are the mechanisms of the stress transfer to the particles, the enhanced work hardening in the matrix, and the significant contribution of the triaxial stress to the stored strain energy. These characteristics of the MMCs give them their high strength, high stiffness and low ductility. Source: Dissertation Abstracts International, Volume: 56-01, Section: B, page: 0464. Supervisor: Daniel F. Watt. Thesis (Ph.D.)--University of Windsor (Canada), 1994.