A research team of the California Institute of Technology (Caltech), led by Dr. Mario Demetriou, discovered a new super-durable and hard metal alloy. Although it looks like glass, it is the first material ever made, which competes in hardness and strength, steel and in the future could replace buildings, bridges, cars and other uses. The challenge for scientists has always been to find materials that are hard and durable, but usually they resulted in a compromise between these two characteristics. The group of M. Demetriou, who published the study in the journal for new materials, Nature Materials, according to “Nature”, he was able to synthesize a metal alloy of “formless” metals, combining the two desirable properties.
Until now, there was very difficult to find material that is both tough and durable. For example, the glass can be hard and not bent on some weight, but tends to be brittle. Other materials such as metals, although there are durable meaning that it much more difficult to crush them, there are more flexible. Such material is the ductile or the malleable iron. Normal metals are weak and elastic because their atoms have a crystalline structure which is easily degraded when the metal is subjected to a heavy weight. But the so-called amorphous metals are more powerful. They are created by rapidly cooled molten metal, causing the atoms to be in a disordered structure similar to the glass, which means that it takes much more energy and weight to move the atoms to other place.
Until now, however, these “glassy metals” seemed to be inherently fragile, because they contain small defects, which are beginning to increase in certain areas, as there is metal fatigue, leading eventually to material cracks and breaks. But US researchers have discovered that if, paradoxically, create artificially an excessive number of such defective areas, it can cause the opposite effect: the material to be more durable. According to Mr. Demetriou, defective areas “intertwined” with each other through networks and, when a crack occurs, then these networks surround the crack and prevent it from spreading.
After 109 efforts, researchers finally discovered the right mix of “glass” (amorphous) metal that can have the greater effect. The alloy consists essentially of palladium, adding little silver and other items. As Richard said, scientists do not yet understand why this mix “works” where others had failed, for the ideal combination of hardness and durability. Doing experiments with the creation, the speed and degree of expansion of different cracks, researchers discovered how strong and durable the new material is. A future prospect would be to investigate whether the addition of more elements in the alloy, in order to create small areas in the crystalline material, would increase even more its durability. On the other hand, because palladium is a rare and expensive metal, the widespread use of such alloy seems at present very difficult. As Greek scholar said, the new material could in principle be used to produce new resistant dental and other medical implants. The researchers said that they would seek a cheaper “version” of the base alloy of copper, iron or aluminum. If they find it, then this material is going replace steel for all construction on a large scale.