中文摘要：

The influences of particle size on the mechanical properties of theparticulate metal matrix composite are obviously displayed in the experimental ob-servations. However, the phenomenon can not be predicted directly using the conven-tional elastic-plastic theory. It is because that no length scale parameters are involvedin the conventional theory. In the present research, using the strain gradient plas-ticity theory, a systematic research of the particle size effect in the particulate metalmatrix composite is carried out. The roles of many composite factors, such as: theparticle size, the Young’s modulus of the particle, the particle aspect ratio and vol-ume fraction, as well as the plastic strain hardening exponent of the matrix material,are studied in detail. In order to obtain a general understanding tor the compos-ite behavior, two kinds of particle shapes, ellipsoid and cylinder, are considered tocheck the strength dependence of the smooth or non-smooth particle surface. Finally,the prediction results will be applied to the several experiments about the ceramicparticle-reinforced metal-matrix composites. The material length scale parameter ispredicted.

英文摘要：

The influences of I,article size on the mechanical properties of the particulate metal matrix composite;are obviously displayed in the experimental observations. However, the phenomenon can not be predicted directly using the conventional elastic-plastic theory. It is because that no length scale parameters are involved in the conventional theory. In the present research, using the strain gradient plasticity theory, a systematic research of the particle size effect in the particulate metal matrix composite is carried out. The roles of many composite factors, such as: the particle size, the Young's modulus of the particle, the particle aspect ratio and volume fraction, as well as the plastic strain hardening exponent of the matrix material, are studied in detail. In order to obtain a general understanding for the composite behavior, two kinds of particle shapes, ellipsoid and cylinder, are considered to check the strength dependence of the smooth or non-smooth particle surface. Finally, the prediction results will be applied to the several experiments about the ceramic particle-reinforced metal-matrix composites. The material length scale parameter is predicted.