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How To Tell If It's Really Titanium
With the growing popularity of titanium, some disreputable merchandisers are passing off other materials as the more expensive metal. Popular Science looks at a surefire way to prove what that credit card/crowbar/ring is really made of. "Hold any genuine titanium metal object to a grinding wheel (even a little grindstone on a Dremel tool will do), and it gives off a shower of brilliant white sparks unlike any softer common metal. The sparks are tiny pieces of cut titanium--the friction of the grinder heats them till they burn white-hot. Hold a grindstone to the shackle of a "titanium" padlock from Master Lock, however, and you'll instead see the telltale fine, long, yellow sparks of high-carbon steel."
Wtf is with these fake links? Do you get money or something for that stupid city?
The author of this Popular Science article, Theo Gray, also recently relaunched http://www.periodictable.com/ Thousands of elemental pictures and videos are available there, all linked in with his Popular Science series.
a: Titanium is not ferromagnetic, and hence it is not attracted by magnets as strongly as iron is ( the difference in force should be orders of magnitude ).
b: Titanium's density is 4.5g/cm^3 , iron is 7.8g/cm^3
c: Titanium is corrosion resistant to dillute sulfuric and hydrochloric acid, iron is not.
...iron is always magnetic.
That is a big fallacy. There are some alloys in which iron is around 98-99% which are non-magnetic (think unusual alloying elements like niobium and rhenium).
I hadn't known there were so many idiots in the world until I started using the Internet -Stanislaw Lem
And yes, I am a loudspeaker engineer... ;)
MERRY CHRISTMAS!
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
A laser spectrometer can do this for you. It will still create microscopic damage though.
Depends on the type of stainless. Austentitic is not ferromagnetic, while martensitic is.
How much are you paying for that service? For $30,000-40,000, you can buy a handheld x-ray fluorescence analyzer. These things got started in testing for lead paint, and now get used to test and check for lots of things - including alloy composition verification. An XRF shines x-rays of a known energy at the test sample, then detects and analyzes the spectrum that is reflected back. Each element has a characteristic x-ray emission spectrum based on the energy of electrons dropping into lower shells. In 10-20 seconds, you can get a really good breakdown of the elements in the test sample.
And in fact, some soldering iron thermostats use this property. When the iron is cold, a magnet pulls the contact closed. Once it heats above the Curie point, the magnet lets go and the contact breaks.
Sorry, that's not my understanding of the metal's properties. I guess for digging around in the sand, you don't really need a fine edge, but nothing to my knowledge compares to the ability of steel (esp. high-carbon steel) to hold an edge. High-carbon steel is very brittle, which helps it to hold an extremely sharp edge; this is why Japanese samurai swords were forged to have one side harder than the other side, so the sharp side would be extremely hard, but the other side would be less hard and more strong (done by using clay on one side during quenching) so that the blade as a whole wouldn't break easily.
There's a reason no other knives are made of titanium, or anything besides steel for that matter.
Titanium is known to be a very strong metal. If you know anything about metallurgy and its terminology, strong and hard are different properties, and usually work against each other: a metal is usually strong, but not hard, or vice versa, not both. Steel can be made to be hard, but brittle, or strong (which is more flexible) but not very hard.
Anyone with a titanium ring knows that it's not a hard metal at all: it's easily scratched unless it has a protective coating (usually diamond). Sure, it might prevent a automatic pressure door on an undersea rig from locking you in, but it doesn't hold a sharp edge at all.