Rapid Hardness of Nano-Structured Metals
Publication Number: 5991-1773EN
Publication Date: 2014.08.03
Language: English
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Rapid Hardness of Nano-Structured Metals

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Introduction

Nano-structured metals are highly valued for their strength. Nano-structured metals are metals which have been manufactured to have grains (i.e. coherent crystals) that are on the scale of 1–100nm. Such materials manifest great strength, because dislocations (i.e. crystalline imperfections) tend to exhaust themselves at grain boundaries due to incoherence.

 

The phenomenon of plastic deformation due to dislocation motion can be understood with a simple analogy: the movement of a loor rug. A loor rug can be moved easily by introducing a kink at one end of the rug, and then pushing that kink to the other end of the rug. When the kink reaches the other end of the rug, it disappears, and the net effect of the motion of the kink is that the entire rug has been moved. Now let us suppose that we place two rugs end-to-end and again introduce a kink at one end of the rug and translate it to the other end. When the kink reaches the end of the irst rug, it does not translate to the second rug due to incoherence between the two rugs. In this way, the second rug remains unaffected by the deformation and net motion of the irst rug.