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Calliopenjo
05-18-2009, 06:22 AM
Hi there,

Is the the world's strongest metal titanium? I just need to double check thanks.

Dommo
05-18-2009, 08:31 AM
This is a really tough question to ask, because it all depends on what you define as "strong"(I'm a mechanical engineer). Titanium is strong for how much it weighs, but is inferior to steel in a lot of ways as well.

I guess the best answer I can give you is to simply define what you mean by strong.

If its volumetric strength(e.g. strength per unit of volume) titanium gets its ass wooped by steel(due to its elastic modulus and ability to be hardened). In other words, where weight isn't a big factor, always use steel. A sword made of steel will be far stronger than an equivalent sword made of titanium(not to mention steel can be better crafted to specific levels of hardness for edge retention) because a 1/2" thick bar of steel will be far stronger than a 1/2" thick bar of titanium. So if size(as opposed to weight) is a factor, steel is a solid choice.

If weight is a factor, then you're left with carbon fiber, aluminum, magnesium, and titanium alloys. These each also have the same issue as above, in that for a given volume they're all inferior steel. Of these, titanium is probably the all around best material, simply because it's isotropic(just as strong being squeezed together as pulled apart unlike carbon fiber), and has a high melting temperature as well as an endurance limit(means it can be engineered to basically never fail as long as loads don't exceed a certain limit, the other materials will eventually fail to a falling hair after enough repeated loads). However titanium is also stupidly expensive compared to a quality aluminum alloy, and magnesium sort of straddles the middleground between aluminum and titanium. Carbon fiber is a good material, BUT it's difficult to work with structurally because of it only be strong in tension, it's absolutely worthless if put under a shearing load and it's pricey.

If heat is a big factor, then you're looking at a material like tungsten, that loses very little strength as the temperature increases, and it can withstand VERY high temperatures.

If corrosion is a factor, stainless steel is a solid choice, titanium is great, but the ultimate matiral is iridium or the other noble metals(gold, platinum, etc.). Iridium is the shit, and is immune to just about anything you could throw at it, but it also costs thousands of dollars an ounce, so it's typically only used in special circumstances.

If I were going to pick an all around material, I'd go with a quality steel(stainless if corrosion is an issue). Steel alloys exist that range from the super hard tool steels, to the soft nearly carbon free steels. Also a large variety of different strength and weight properties means that somewhere there's probably a steel that exists that is tailor made for the job. Not to mention that steel is pretty affordable and readily available.

Puma
05-18-2009, 04:01 PM
Excellent post, Dommo - I learned a lot from it, but I do have another question. What about beryllium, where does it come into the scenario? When I was working in aerospace, we were using beryllium for guidance system components. Thanks for your response. Puma

TabithaTodd
05-18-2009, 05:26 PM
actually a combination of titanium and tungsten carbide is the strongest. There is something called kempura (Japanese old style metal tempering that makes it extremely strong and unique is looks) - I think that's the name of it.

There's also titanium\platinum\tungsten carbide mixes that are extremely strong metals - you won't find anything stronger than a mixture of several metals.

waylander
05-18-2009, 05:46 PM
Berylium is also very light similarly to Magnesium (but very toxic)

Dommo
05-18-2009, 10:29 PM
I haven't worked with berylium, but I've heard it's got similar properties to Magnesium. All of your steels are alloys. Typically they're a blend of Iron, Carbon, Manganese, and other metals.

Aluminum's big problem is that it's got a low melting point, and it's weak compared to steel and other metals. It's strength is that it's easy to machine, resistant to corrosion(it oxidizes favorably), and that it's cheap.

Magnesium's big problem is in the production of it. It's strong for it's weight, but magnesium is dangerous to produce, as it's extremely flammable when being converted into a pure metal from its natural ore. This makes it expensive to acquire in large amounts.

Titanium has a similar problem with magnesium in that the production of the metal is very expensive. It's mechanical properties are pretty good, and it's got an endurance limit like steel does. Not to mention it's resistant to corrosion. The only problems with the metal itself, is the cost and the difficulty of machining it safely due to combustible sparks.

Steel in my book is probably the best "all around" material. If you look at something by a combination of its price, availability, versatility, hardenability, etc., steel can't really be beat. Sure there are metals that have higher tensile strength, or are lighter, but few have the combination of good properties that steel does, and at the same time are affordable. If it wasn't so prone to rust, it'd probably be the "ultimate" material, although that's why you've got stainless steels.

Calliopenjo
05-19-2009, 04:57 AM
Thank you for your responses. :Hug2:

I need a material to build an impregnable cage. An indestructible metal that's shiny but at the same time can't be cut, melted, or dissolved either. Weight isn't the issue.

Titanium popped into my head that's why I thought Titanium. That and I Googled World's Strongest Metal and Titanium popped up.

waylander
05-19-2009, 01:05 PM
Any metal can be cut, melted or dissolved with the correct choice of tools/chemicals.
The point is: how much trouble is it to do it?