The Role of Powder Materials in Defense, Energy, and Security Systems

Abstract

Multifunctional powder materials with unique combinations of properties have been synthesized recently. Among them, ultrafine materials and nanomaterials are now beginning to play a very important role in answering some of our current global challenges. Because the properties of nanomaterials are very different from those of their conventional counterparts, they have capabilities not offered by conventional materials. This difference is so for many reasons, such as (I) dimensional changes experienced at the molecular level; (II) a consequent degree of perfection where the absence of all kinds of defects allows intrinsic properties to reach the highest values ever measured and, in certain cases, reach and surpass the theoretical limit; (III) a considerable change in specific surface area and associated properties; and (IV) the capability of development of nano-architectures not feasible in conventional materials. Among the intrinsic properties to be considered and leveraged are strength, stiffness, toughness, thermal and electrical conductivity, and others. From those associated with a specific surface are surface tension and surface concentration, catalytic and photocatalytic activity, melting point, and others. Because of these unique and exceptional properties, nanomaterials and ultrafine materials have great potential for applications in three very important 21st century industries: defense, energy, and security. In defense, nanomaterials and ultrafine materials are now being used for many applications, such as nanoelectromechanical systems (NEMS) and microelectromechanical systems (MEMS) devices; specially engineered reactive materials; advanced penetrators; strong, tough, and lightweight vehicle structures; advanced sensors; thermal protection; thermal management system; effective tank and personnel armor; and in wear and thermal protection systems. Energy security has become a major issue as fossil fuels are confined to just a few areas in the world and their availability is controlled by political, economic, and ecological factors. A global coherent energy strategy that encompasses the entire energy life cycle is required to address all the forms of energy harvesting, storage, conversion, transmission, and distribution. In the short term, focus should be placed on achieving higher energy efficiency in all industries and processes and on increasing supplies from all forms of alternative and renewable energy, those currently available and others to be developed. Clean water supplies have become a critical and expensive resource. Worldwide water supplies and treatment infrastructures are experiencing increasing challenges in coping with an increasing demand for clean and purified water. Currently, globally, more than 1.5 billion people do not have access to safe and adequate water supplies. Water security, like fossil fuels, is becoming a major issue, and its availability may become controlled by political, economic, and ecological factors. Here, too, there is a need to develop a global coherent water sustainability strategy that encompasses all sorts of water resources. Nanomaterials with a large active surface area and a variety of morphologies, such as nanotubes, nanorods, nanosheets, dendrimers, and nanoparticles, have the potential to impact the development of secure and cost-effective water treatment technologies. The series of four articles assembled on this topic in this issue of JOM explores the harvesting of some of these fundamental properties and their application to challenges and innovations in defense, energy, and security systems. One of the major current challenges in the science and technology of nanomaterials is the capability of Fernand D.S. Marquis is the guest editor for the Powder Materials Committee of the TMS Materials Processing & Manufacturing Division, and coordinator of the topic Powder Materials in Defense, Energy, and Security Systems in this issue. JOM, Vol. 66, No. 6, 2014