(Nanowerk News) Metallurgists have all kinds of ways to make a chunk of metal harder. They can bend it, twist it, run it between two rollers or pound it with a hammer. These methods work by breaking up the metal’s grain structure — the microscopic crystalline domains that form a bulk piece of metal. Smaller grains make for harder metals.
Now, a group of Brown University researchers has found a way to customize metallic grain structures from the bottom up. In a paper published in the journal Chem (“Bulk Grain-Boundary Materials from Nanocrystals”), the researchers show a method for smashing individual metal nanoclusters together to form solid macro-scale hunks of solid metal. Mechanical testing of the metals manufactured using the technique showed that they were up to four times harder than naturally occurring metal structures.
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