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Materials by Design [2011-04-25] |
| Science 12 May 2000: Vol. 288 no. 5468 p. 995 DOI: 10.1126/science.288.5468.995 Pathways of Discovery Materials by Design Gregory B. Olson To design a material is to try to meet a material user's need. A good place to start is with property cross-plots, like those of Michael Ashby, that graphically define property-performance relations (1). These help engineers select materials for their product designs. They're useful for defining a quantitative set of property objectives that will sum into the materials performance needed by users. These performance specifications are determined by the role of the potential material in the wider system it serves. They also help define economic parameters, such as the cost of raw materials and processing, for the overall material design task. With objectives and economic constraints defined, the linear three-link framework of materials science and engineering serves to guide the design and development phases. The Steel Research Group (SRG) (see main text) uses flow-block diagrams that represent 1) key microstructural subsystems (such as crystal grain sizes), 2) the primary links of these subsystems to the properties they control (such as strength and toughness), and 3) the stages of processing (such as tempering or reheating) that govern their dynamic evolution. With these in hand, systems analysis is then applied to identify and prioritize key structure-property and processing-structure relations. Often, part of this exercise involves some additional modeling or empirical data gathering to fill gaps in the knowledge required for making practical decisions about composition and processing details. The systems view operates here at the strategic level, but it is supported by traditional reductionist analysis at a tactical level. On balance, the procedure greatly reduces the amount of costly experimentation in materials creation. Instead of making tens of prototypes along the way to a useful new material, SRG designers reach their target metal using only a few actual melts to refine the computation-heavy design efforts. References ↵ M. F. Ashby, Materials Selection in Mechanical Design, Pergamon, Tarrytown, NY, 1992 . |
