The Science of Materials: from Materials Discovered by Chance to Made-to-Measure Materials
- Cet article est une traduction de :
- La science des matériaux :
du matériau de rencontre au matériau sur mesure
Notes de la rédaction
Excerpts from the Inaugural Lecture 13 January 2013
Source: La lettre, no. 36, December 2013
1Historians have customarily named the different ages of humanity after the materials that prevailed at the time: the Stone Age, the Copper Age, the Bronze Age, the Iron Age, etc.
2The nineteenth century can be seen as the Steel Age, the twentieth century as the Age of Polymers and then Silicon. This habit is telling: the successive stages of our material civilizations are facilitated by the development of materials and energy resources.
3While the materials used by human beings have continuously evolved, this has happened at very different speeds over the course of history, and has accelerated considerably in recent decades. In pre-historical times, around 50,000 BCE, the only materials our ancestors used were natural ones, be they mineral or organic. The choice of materials was essentially limited by their proximity. Later, say around 50 BCE, the diversity of available materials had grown substantially. The Romans had excellent knowledge of ceramics and glass, they used both stone and mortar, and their work with metals, silver, gold, tin, lead, bronze and planished iron demonstrated good empirical knowledge of metallurgy, albeit not as great as that found much earlier in Far Eastern civilizations. Between the Roman Empire and the end of the Middle Ages, the world of materials evolved relatively little. While the engineers of the Middle Ages learnt to use civil engineering materials, as witnessed in the powerful religious architecture of the time, they did so with local raw materials: limestone in Reims, volcanic stone in Clermont-Ferrand and wood in Norway. The nineteenth century was unquestionably the century of metals, particularly ferrous materials. Cast iron and steel allowed for bridges, ships, trains and later cars to be built. The industrial revolution was as much that of steel as it was that of the steam engine. The twentieth century saw two revolutions: metals and ceramics, which prevailed. Artificial polymers emerged, made from petroleum, with the fascinating variability of their properties, and the capacity to “build” matter on an atomic level, by playing with the arrangement of the chains. The second revolution of the twentieth century was the forceful appearance of functional materials, in much smaller quantities, but with very high added values. The electrical energy revolution was made possible by materials that already existed. The microelectronics revolution required the manufacturing of very pure silicon, and the optic fibre revolution could not have occurred without the ability to use highly pure glasses with a gradient index.
4The historical trend I have just outlined reflects not only the evolution of available materials, but also that of the way humans relate to materials, successively moving from the “materials discovered by chance” to the “optimized material”, then “competition between optimized materials” and finally the “construction of made-to-measure materials”. This trend, which will be the common theme of these lectures, also reflects the shift from know-how to a science, then to a body of sciences, called the “engineering sciences”.
5This is effectively technological innovation. Today, we are faced with what some have called “the hyper-choice of materials”. There are about 100,000 materials available to engineers, with a wide variety of processes to apply them. Every day new materials are discovered, though only a limited number of them make it out the laboratory. A material is rarely used for a single property, but for a combination of properties, and for its possibilities of implementation. And despite the variety of materials available, in each domain of application, a limited number of families prevail: in the building industry, glasses, steels and concretes; in the car industry, steels, aluminium alloys and polymer composites; and in microelectronics, silicon remains the largely prevalent semi-conductor. But innovation is far more here than the extension of a catalogue of options. The three pillars of the modern science of materials, the optimization of materials, that of choices between materials, and finally the design of made-to-measure materials, constitute a profound evolution of the way we use matter.
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Yves BRéCHET, « The Science of Materials: from Materials Discovered by Chance to Made-to-Measure Materials », La lettre du Collège de France [En ligne], 8 | mars 2014, mis en ligne le 11 août 2015, consulté le 25 mars 2017. URL : http://lettre-cdf.revues.org/1998Haut de page
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