The right combination

Abstract

In the simplest sense, a composite is an object made up of two or more distinct parts. A common example is a composite image that may come from a series of photographs that together tell a bigger story than could be achieved with only one image. Within materials science, composite materials are put together from two or more components that remain distinct or separate within the final product. They can be as simple as a matrix material that envelops a reinforcing material, as when concrete surrounds steel bars that help prevent the concrete from failing under tension. Beyond this simple construct, composite forms now include layered structures and reinforcing agents that act in all three dimensions. The challenge is that the options for making a composite are almost limitless, but only a few combinations of materials will combine synergistically, and the design criteria may not be obvious. To design a material that will absorb more energy before breaking, a weaker reinforcing material may be added. When this composite fails, it may form a much larger number of cracks, and it is the additional crack length that makes the material tougher. ..