Statistical investigation on influence of grain size on effective strengths of participate reinforced metal matrix composites

摘要

In this paper, a numerical technique is presented for evaluating the influence of particle size in particulate reinforced metal matrix composites (PRMMCs) on two critical material parameters, namely, the ultimate strength and endurance limit. To demonstrate this technique a representative PRMMC material, tungsten carbide-cobalt hard metal (WC-Co), was selected. As a typical random heterogeneous material, WC-Co demonstrates a noteworthy randomness in its composite structure. In order to take this characteristic into consideration, a novel numerical approach is adopted in this work, which is a conjunction between so-called direct methods (DMs) and statistical analyses. As the approach requires a large number of samples to be evaluated, numerical efficiency in solving optimization problems resulted from DM is a critical issue. For the purpose of comparison with the lower bound formulation, a numerical scheme formulated from the upper bound method is selected in this work. Overall, the study clarifies how the material strength of WC-Co with a fixed binder content is influenced by the reinforcement WC particle size and shows how the proposed approach can be used as a viable means for investigating the relationship between properties and structural characteristics of PRMMC materials. (C) 2019 Elsevier B.V. All rights reserved.