State of raw materials 2013: Overview and new frontiers

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State of raw materials 2013 Overview and new frontiers By Eileen De Guire Gregory Rohrer describes eight grand challenges identified at the workshop, with the caveat that there are likely more. Some research groups are already developing new materials that push the frontier of traditional materials. In the lead article of this issue, for example, Xudong Wang writes about a new class of materials—piezotronics— that are semiconductors with piezoelectric properties and use strain to engineer the band gap. Their fascinating properties are just starting to be explored, and could yield big dividends in energy and process industry applications. New materials development has a practical side, too, and it behooves manufacturers to proactively address occupational health and safety issues. Especially in the realm of nanomaterials, new questions arise about materials handling and worker exposure in production environments. The medical community is responding with research on how nanomaterials enter, move through, and interact with living organisms. The Center for Disease Control’s National Institute for Occupational Safety and Health works with manufacturers on a voluntary basis to develop safe protocols for nanomaterial manufacturing. See the article, ”NIOSH research and resources for safe handling of nanomaterials,” for details. While we wait to see what new, previously unimagined materials and applications await us across the frontier, the “Mineral Commodity Summaries 2013” report published by the United States Geological Survey reminds us that the manufacturing economy is the “here and now.” Its health depends on access to reliable supplies of raw materials. The numbers tell the story. The report estimates the value of mineral raw materials produced at mines in the US was $76 billion, up from $74.8 billion in 2011. The value of domestic raw materials combined with domestic recycled materials is estimated to be in the neighborhood of $2.4 trillion in 2012. According to the USGS report, 2012 represented the third straight year of growth for the mineral production industry. Minerals contribute to the US gross domestic product on several levels—mining, processing, and manufacturing. For the second consecutive year, the contribution of minerals to GDP grew. The economy’s harbinger construction industry fuels demand for minerals and products like cement, sand and gravel, and gypsum that are used almost exclusively for construction, not to mention the mineral raw materials used to make steel, windows, tile, fixtures, etc. Imported minerals continue to be important to US manufacturing. According to the report, more than half of the consumption of 41 minerals in 2012 was imported. Eighteen of the 41 commodity minerals were 100 percent imported. This is about the same level of import-dependence as 2011 and 2010. H ow far can we push materials? That core question defines the discipline that is materials science. The question implicit in the Materials Genome Initiative is, “must innovation be at the mercy of known materials?” The finite set of raw material compositions and the limited ways that chemistry and processing allow them to be combined impose limitations on the structure, chemistry, and, ultimately, properties of manufactured components. Materials science, in many ways, has been a materials selection and product design problem, not a “materials design” problem. MGI flips the question, and asks what properties are desired, and how can we use what we know about structure at the electronic and atomic levels, to engineer materials with specified properties from first principles? However, MGI is only a formalization of a trend. The discovery of nanomaterials—actually, the discovery of ways to observe nanomaterials—opened the door to engineering materials on length scales not previously imagined. This required development of newer, more powerful characterization tools, but also computational methods that allow modeling across length scales that span many orders of magnitude. After all, even nanomaterial-based products interact sooner or later with users on a “people scale.” The ability to model, synthesize, and characterize materials on such small scales led, perhaps inevitably, to researchers challenging boundaries, stretching theories, and demanding that materials deliver more of their intrinsic potential. To this end, a group of researchers embraced the challenge of identifying the “grand challenges” of ceramic science at a NSF-sponsored workshop in spring 2012. They asked what are the compelling scientific questions that, if answered, could lead to the development of game-changing new materials, like oxide-based electronic devices? What questions, if answered, could lead to superior performance of existing materials, like maintaining the intrinsic strength of glass? The article in this issue, “Expanding the frontier—Grand challenges in ceramic science,” by 24 www.ceramics.org | American Ceramic Society Bulletin, Vol. 92, No. 6


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