NanoMicro Composites

In previous work, we have demonstrated that the rate-sensitivity of nanostructured fcc metals increases with decreasing grain size, making these materials more stable and therefore potentially useful in armor applications. However, traditional aluminum based materials, while light, do not have the strength to be effective for vehicular armor applications (the comparative standard being rolled homogeneous armor or RHA). Can one use reduction in grain size to drive up the strength of aluminum-based materials sufficiently to make them competitive? Early work in nanocrystalline aluminum suggested that while the strengthening capacity exists, the ductility of these materials is too low for them to be effective. However, Evan Ma and colleagues at Hopkins showed that a proper choice of grain size distribution could enhance ductility while retaining strength in nanostructured copper.

Long-Range Objectives

· Determine the deformation and failure mechanisms in nano-micro aluminum alloys and their composites subjected to impact rates of loading

· Develop models for the dynamic deformation and dynamic failure of nano-micro composites.

Penetration into new aluminum armor

Lightweight nanomicro aluminum alloys

CRG