View Full Version : Metallurgical question.

05-10-2011, 11:13 PM
Is there a simple way to determine if a metal is titanium?

L.W. Baxter
05-10-2011, 11:32 PM
Do the bite test. If it breaks your teeth, it could be titanium!

Old Dryfoot
05-10-2011, 11:49 PM
You can weigh it or do a spark test, when touched with a grinder you get a shower of white sparks, and titanium is non magnetic. Also is a faily unique color and does not oxidize so those traits could help you identify it as well.

The Bigfella
05-10-2011, 11:51 PM

Dave Wright
05-11-2011, 12:13 AM
How big is your sample? Do you have an accurate scale. Can you measure it's weight in air and water, or do you have a suitable graduated measuring bucket, or the patience to carefully measure it's volume in overflow from a big bucket to a small graduated beaker? Archimedes provided the method and it's a good exercise to review that method. It's an accurate method and it has great relevance to boats too. Enjoy!

Old Dryfoot
05-11-2011, 12:16 AM
Do a displacement test, drop the metal into a an absolutely full container of water, so full that as soon as you start to submerge it the water begins to overflow, catch all of this water as it overflows. Now measure the displaced water in millimeters, divide the weight of the item by the amount of water displaced, each ml of water will equal 4.506 grams if titanium.

05-11-2011, 12:21 AM
it doesn't make for good axles.

Bob (oh, THAT Bob)
05-11-2011, 12:51 AM
If you look closely with a magnifying glass, you can see all of the indigenous Titans.

But seriously, Titanium is a silver metal that is about 1.5 times as heavy as aluminum and half the weight of steel, if I recall correctly. This is a good margin. Any good measurement of density should easily distinguish it from those metals. I think it could be some other element or an allow that is close to the density of Ti, but I can't think of what off the top of my head. If the material is a regular shape like a cube or cylinder, you can just calculate the volume, weigh the sample, then calculate to determine density. Otherwise, either determine the volume by dropping it into a large enough beaker or graduated cylinder of water, or doing the overflowing bucket method as noted above. If you don't know how to do the above things, you don't deserve to be holding anything constructed of titanium. Put it down. You might break it.


Ian McColgin
05-11-2011, 07:02 AM
Rather than finding volume from overflow, where a truely noticable error would come from water that does not fall all the way to cachment, I'd scribe the water level before and then after immersing the object. If you're using a round section bucket, even with top larger than bottom, the calculation will then be easy and quite exact.

So what's the deal? Got an overpriced knife with what's claimed to be a titanium handle and you've cause to doubt?

05-11-2011, 09:35 AM
Probably a bicycle.
Don't really want to submerge it?

05-11-2011, 05:25 PM
I have access to some free scrap that I am told may be titanium. I thought it could be useful for making bits and pieces from.

I guess it fails Bigfella's cost test.

The Bigfella
05-11-2011, 05:27 PM
I have access to some free scrap that I am told may be titanium. I thought it could be useful for making bits and pieces from.

I guess it fails Bigfella's cost test.

OK, if its failed.... send it over. I have some ideas for it... all motorcycle-related.

ps... I'll pay for the postage.

05-11-2011, 05:32 PM
In the seventies my motorcycling cronies used to call it unobtainium.

The Bigfella
05-11-2011, 06:16 PM
Yep... I've had some thoughts about some bits that could be made.

Meantime, a mate is now in charge of a CNC machine that doesn't get enough work. He says his employer is happy for him to do "foreign orders". My only problem is that my resident CAD man is time poor (ie my mech. engineering student son - who is trying to get his thesis finished).

I'd like.... a titanium centrestand for the Super Enduro, a machined aluminium twin HID 7" headlight mounting system, some handlebar risers,.... and so on. I'd really like a fabricated rear subframe incorporating additional fuel storage. And..... a complete set of titanium bolts for the bike would be nice, and......