4 ms·
That's not at all how or why quenching works. Quenching is used to accelerate the rate at which a metal alloy solidifies/crystalizes such that the internal arr
by fizx 11y ago
That's not at all how or why quenching works. Quenching is used to accelerate the rate at which a metal alloy solidifies/crystalizes such that the internal arrangement of the components is affected. Quenching has nothing to do with density, and since pure carbon is neither metallic or an alloy, quenching pure carbon makes no sense at all.
- gjmulhol 11y agoHere they are talking about surface quenching, where the amorphous carbon thin film is heated then rapidly cooled on the surface. Instead of forming smaller precipitates, like in an alloy, it just forms very small crystals that happen to be extremely hard. They are embedded in amorphous material. The key phrase that capture this is: "This Q-carbon has amorphous structure with some embedded nanocrystalline diamonds the number density of which is determined by the nucleation time available for growth." Hopefully this clears things up somewhat. Pure carbon is actually metallic at sufficiently high temperatures, as reported in this paper and in this citation: [1]. 1. F. P. Bundy , W. A. Bassett , M. S. Weathers , R. J. Hemley , H. U. Mao , and A. F. Goncharov , Carbon 34, 141 (1996).http://dx.doi.org/10.1016/0008-6223(96)00170-4 http://dx.doi.org/10.1016/0008-6223(96)00170-4
- jacquesm 11y agoHm, ok. I'm happy to stand corrected. What I remembered was the outer layer cooling more rapidly than the inner layer resulting in a different crystal layer on the outside and tension in the steel leading to a different density than you'd get otherwise but that is apparently wrong. I'll read up on it, I don't like mis-remembering stuff like this. Thanks for the correction!
- andrewflnr 11y agoIIRC that's what happens in glass with Prince Rupert's Drops (according to Smarter Every Day).