Army focused research team on functionally graded armor composites

With the emphasis on smaller but more mobile combat forces to meet a broad range of mission requirements, future weapon platforms and upgrades will require materials to do better, do more, weigh less, size less and cost less. Metal matrix composites (MMCs) are such material candidates for niche Army applications such as armor, armaments, and vehicle structures. Under the shadow of shrinking resources, a focused research team (FRT) composed of the US Army Research Laboratory (ARL), academia, and small business was assembled to address MMC issues for Army applications. The immediate focus of this team is on the development of MMCs with a tailored ceramic-to-metal through-thickness gradient known as functionally graded armor composites (FGACs). The goal is to provide the science and technology to deliver a high space and mass efficient armor material for ballistic protection against light to medium threats. Technical issues being addressed by this team encompass the role of microstructure in affecting the dynamic flow and ballistic performance of FGACs, high-resolution non-destructive evaluation (NDE) techniques, joining FGACs to dissimilar materials, and the availability of versatile low-cost near-net-shape processing of FGACs. In this paper, highlights from these activities are presented. They include high-strain-rate testing and modeling, apertureless near-field optical scanning microscopy (ANSOM) of FGACs, micro- and nano-scale self-propagating high-temperature synthesis (SHS) reactions, ballistic evaluation, and pressure assisted casting. These efforts represent key technologies necessary for prompt delivery of FGAC technology to the warfighter. (C) Published by 1999 Elsevier Science S.A. All rights reserved.