Metal Reinforcement With Inorganic Fibers

With a few exceptions, metal matrix composites (MMCs) are still in a development stage although it is well known that the presence of inorganic fibers in a metal matrix has a major effect on the properties of the metal. The reinforcement and manufacturing costs are inevitably too high for the potential markets, such as that of automotive engines [29-33]. 

Hierarchy can be described in analogy to rope (stretched polymer molecules in domains that make up nanofibers, combined to microwhiskers, bundled into fibers that are spun into yarn that is twined to make up the rope). Wood and tendon are biological examples that have six or more hierarchical levels. Compared to these, fiber-reinforced matrix composites made up of simple massive fibers embedded in a metallic, ceramic, or polymer matrix are primitive. Hierarchical inorganic materials, as discussed in Chapter 7, can be made with processes for fractal-like solid products spinodal decomposition, diffusion-limited growth, particle precipitation from the vapor, and percolation. Fractal-like solids have holes and clusters of all sizes and are therefore hierarchical if the interactions... 

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