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In spite of our understanding of chemistry, metallurgy still has quite a few mysteries in store for us. Some of them go back thousands of years. For instance we
by srean 15y ago
In spite of our understanding of chemistry, metallurgy still has quite a few mysteries in store for us. Some of them go back thousands of years. For instance we still have not been able to come up with a convincing reproduction of Damascus steel, the prized material that middle eastern swords were built of http://en.wikipedia.org/wiki/Damascus_steel http://en.wikipedia.org/wiki/Damascus_steel. Another supposedly related and "lost" steel is wootz steel. http://en.wikipedia.org/wiki/Wootz_steel http://en.wikipedia.org/wiki/Wootz_steel Perhaps a good term to describe the study of these materials would be forensic metallurgy. My closest brush with metallurgy was in a high-school chemistry text-book, which to be honest bored me to death. But at a different level it instills respect for the ingenuity and persistence of humans. Those methods are by no means simple and the bronze-age and iron-age men figured it out.
Among other things that make recreating these materials hard, is that in cooking them you not only need to get the ingredients right, but also get the sequence correct, sometimes to the minutest detail. Impurities in parts per million or the lack of can have significant effects in determining the properties of the material. Same goes for the process of making it.
We understand properties of individual components well enough but the physics that dictates the properties of alloys is different, difficult, non-smooth and very non-linear. Statistical physics have played a huge role in trying to model these behavior.
Another historical-metallurgical curiosity is the surprisingly corrosion resistant iron pillar in Delhi. It has been out there, in the open, facing the corroding elements of tropical weather for 25 centuries, but with little or no corrosion damage.
Edit: http://en.wikipedia.org/wiki/Iron_pillar_of_Delhi http://en.wikipedia.org/wiki/Iron_pillar_of_Delhi
- deleted 15y ago[deleted]
- hugh3 15y agoIndeed. The other problem with metallurgy is that it's awfully complicated on all sorts of scales from the atomic to the micron scale. Most materials and chemicals out there we now have a pretty darn good understanding of, thanks to being able to sit there and simulate the atomic structure of the material in the computer. But metals like steel are far too complicated since you're not just interested in hundreds or thousands of atoms at a time. To understand steel and predict its properties you need to understand all the impurities and the grain boundaries -- these things occur on scales which are far too large for simulation. So metallurgy remains somewhat like baking a cake. We can bake all sorts of tasty cakes, but there are other cake recipes out there yet to be discovered which might taste even better and we have no idea how to get there from here. (And for this analogy to not completely break down let's just assume that "tastiness" is both objective and measurable even though it isn't...)
- thebooktocome 15y agoNo need to assume that! Some people like key lime, some people like pecan -- just like some people like their steel galvanized, and some people like their chrome-nickel-steel.
- ars 15y agoThe interesting thing about steel is that the tiny grains that make it up are immensely strong, far stronger than any other material we have. But we have no known method of making steel out of just those grains, it's always mixed with other weaker parts. That's why spider silk is so incredibly strong - it's manufactured (essentially) one atom at a time. If we could manufacture steel in the same way it would be far stronger than spider silk. Here's a list of some of the various grains in steel: Pearlite, Cementite, Bainite, Austenite (there are many more). The steel making process is all about encouraging a specific type (and especially, mixture) of these grains to form. But we can do so only at low efficiency and in a random fashion.
- rorrr 15y ago> The interesting thing about steel is that the tiny grains that make it up are immensely strong, far stronger than any other material we have. That's not true, there are many materials stronger than steel: 1) Graphene 2) Titanium 3) Spider silk 4) Carbon nanotubes (buckypaper for instance) 5) IsoTruss carbon fiber 6) Metallic (palladium) glass 7) Transparent aluminum
- ars 15y agoYou misread what I wrote. Not bulk steel, rather the tiny grains are stronger.
- eru 15y ago> 7) Transparent aluminum Just joking?
- ars 15y agoHe might not be, transparent aluminum is also called: Alumina Aluminium oxide Corundum Sapphire Ruby Lots of names for the same thing. It's an incredibly hard material, but it's not really strong, if you define strong as tough. It forms immediately on the surface of all aluminium that is exposed to air, and prevents the aluminium from corroding any further.
- 15y ago