Manufacturing and Fracture Behavior of Large Scale Multilayered Metal-Ceramic Nanocomposites

Uniform and multilayered nanocomposites are of growing interest due to their desirable mechanical properties and their performance under high stress, wear, and impact conditions. Composite structures offer an opportunity to combine the useful properties from multiple materials. Controlled variations in composition and microstructure within a composite material allow for tunable local variations in properties. The simplest version of such a variation is to periodically change the composite volume fraction to create a multilayered composite material. Such structures would have hard layers to maintain strength and softer layers to allow for greater plasticity and prevent brittle failure. We are able to manufacture uniform and layered composites of nickel matrices embedded with alumina nanoparticles using electrodeposition. In this method a rotating disk electrode (RDE) is used to directly control the rate of particle incorporation. Uniform composites are made by holding a constant RDE rotation rate while layered composites are manufactured by periodically varying the rotation rate during deposition. We have demonstrated this novel manufacturing process for large-scale samples, several square centimeters in area and hundreds of microns thick, while maintaining submicron microstructural resolution.