The following collection of papers highlights recent developments in the consolidation processing of powder materials. Like hightemperature oxide superconductors, particulate materials M.G. McKlmpson offer tremendous potential for new advancements in materials technology. Today's powder practitioners can exploit a host of powerful techniquesincluding atomization, solid-state-microblending, nanoscale processing, and chemical synthesis-to produce particulates exhibiting properties that cannot be attained using more conventional bulk processing. As with the oxide superconductors, however, the economic potential of these materials can only be realized by developing cost-effective, environmentally acceptable processing technologies for converting powder materials into useful engineering products. A key element of contemporary materials development is the concept of the materials system, which means that a material's performance, processing, and price are interrelated and must be "balanced" in an economically attractive fashion. This concept is clearly not new; the Bessemer converter became a commercial success in the mid-1800s because it produced a new material (steel) with attractive performance characteristics at a much lower cost than the existing "puddling" process for wrought iron. Nevertheless, in today's competitive environment-with its stringent requirements for performance, reliability, and low cost-such a multidimensional systems orientation is absolutely crucial. The following articles nicely illustrate this interrelationship. The first paper, by A. BoseofParmatek, reviews recent developments in powder-injectionmolding.Itbrieflydescribes the injection molding process and points out its principal advantages and limitations from a commercial perspective. The paper discusses the engineering requirements that are well served by injection molding, including size, wall thickness, and dimensional tolerance. In addition, Bose describes the starting powders required for successful injection molding
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