the MMCs (Metal Matrix Composites) generally consist of an heterogeneous system where a non-metal phase is dispersed in an alloy. They can be theoretically customized to specific applications by just changing some qualitative-quantitative parameters of the matrix and of the reinforcing phase. Such composites, having a lower density than the matrix, generally show higher mechanical properties, which make them economically competitive for special uses (for example in the aeronautical and automotive fields). In these applications indeed, a decrease in density, obviously leads to a lower fuel consumption and higher performances, which is a very important parameter. However, in order to improve their reliability, their corrosion resistance properties need to be ascertained, through a detailed analysis of the type of material and likely interactions in aggressive environments. In fact, the heterogeneity of the material could compromise its service life owing to corrosion attack. The characteristics of the composite are strictly linked to different factors: porosity, precipitation of intermetallic phases that can be cathodic in respect to the matrix, formation of reaction products at the matrix-particle interface, matrix composition and characteristics of the reinforcement (type, amount, shape, etc.). You should have the physical-mechanical characteristics required of your product or a material to refer to and try, acting on concentration, size, dispersion, etc. of your reinforcing phase (in first is more simple, for obtain anisoptropic characteristic, you can use particles as reinforcing phase), to achieve an equal or better result.