4130 vs Titanium?

[rtfm]

Hi,
Anyone know where I can find info on the relative weights/strengths of 4130 vs Titanium tubing? Just interested...

Regards,
Duncan

[automan1223]

You need lasers and special tools to work with titanium.

Forget about it.

[M. Pearce]

Duncan,
I bought a muffler for my race car a while back and it is made of Titanium. The guy that sold it to me before shipping it said it weighed 3LB's. I thought no way and sent the money for shipping anyway. When the mufler came in, sure enough, 3LB's for the entire muffler. The muffler is a lot stronger than my usual stainless race mufflers in the past. The only problem is not any muffler shop want's to install it for me so I gotta do it myself with clamps. Go to steel supply websites and usually they will have a chart on their metals they sell. I'll go and check my local supplier and see about getting one for you. Be Back! Here is a link, probably what you are looking for.

http://www.thefabricator.com/TubePip...icle.cfm?ID=22


Mark P

[rtfm]

Thanks for the link. Very interesting.

Regards,
Duncan

[Jazzenjohn]

All data from www.matweb.com


6061-t6
Ultimate tensile strength (UTS) = 45000 psi
Yield tensile strength (YTS) = 40000psi
Shear strength (SS) = 30000 psi

4130
UTS = 97000 psi (144000 hardened and tempered)
YTS = 63000 psi (130000 hardened and tempered)
SS = not listed

6al4v Titanium
UTS = 170000 psi
YTS = 160000 psi
SS = 80000 psi

I found some 3al2.5v titanium tubing .75 od .050 wall available surplus for 19.08 a foot

[Hognose]

Titanium is very hard to work. Not the worst thing (that would probably be Inconel).

It doesn't substitute 1:1 for aluminium or steel. Note that many of our steel structures rely on steel's delta betwen yield and ultimate strength for energy absorption. Like aluminium, titanium has a very small plastic zone, so plastic deformation of titanium alloys is of more interest to crash investigators than design engineers -- IMHO.

cheers

-=K=-

[plastic]

Originally Posted by automan1223

You need lasers and special tools to work with titanium.

Forget about it.

Work it the same as you would work stainless steel.

[RayPierce]

Originally Posted by Hognose

Titanium is very hard to work. Not the worst thing (that would probably be Inconel).

It doesn't substitute 1:1 for aluminium or steel. Note that many of our steel structures rely on steel's delta betwen yield and ultimate strength for energy absorption. Like aluminium, titanium has a very small plastic zone, so plastic deformation of titanium alloys is of more interest to crash investigators than design engineers -- IMHO.

cheers

-=K=-

I know nothing of "elasticity or delta yield" thingies you spoke of.
Not knowing anything about metalurgy would a wheel axle be worse made of titanium that it would from steel as most are?

I have couple of pieces of Ti that I could make axles for my Gyrobee.
Cost was free so that isn't a factor.
Just wondering if the weight savings would be worth it.

[rtfm]

Hi,
I was wondering about the relative strength of Carbon Fibre tube vs 6061-T6 vs 4130 tube for constructing the typical mast/keel arrangement found on many gyros.

I know, for example, that redundant 2"x1" 6061 sections (with suitable gusset plates) have proved themselves perfectly adequate to bear the loads of supporting the tail feathers on most pusher gyros. Even strong and rigid enough to allow fitting a tail wheel and using this to land on initially.

I can certainly continue this tradition, but the idea occurred to me that it might be possible to construct the same tail geometry out of 4130 tubing, or even Carbon Fibre tubing. Certainly the CF tubing option would weigh less, but right now I don't really know much else.

Specifically:
(1) What OD/wall thickness of CF tube would be required to give similar strength as 2"x2" 6061?
(2) Similarly, comparitive dimensions for 4130 tubing.

Is there a web site I could visit for these comparative figures? Or does anyone of the forum know the answer?

Kind regards,
Duncan

[rtfm]

Hi,
I've visited the matlab web site, and although it has an impressive arrary of lists, fact and figures, I don't really know what I'm looking for. Help?

Duncan

[bart_dood]

Originally Posted by rtfm

Hi,
I was wondering about the relative strength of Carbon Fibre tube vs 6061-T6 vs 4130 tube for constructing the typical mast/keel arrangement found on many gyros.

I know, for example, that redundant 2"x1" 6061 sections (with suitable gusset plates) have proved themselves perfectly adequate to bear the loads of supporting the tail feathers on most pusher gyros. Even strong and rigid enough to allow fitting a tail wheel and using this to land on initially.

I can certainly continue this tradition, but the idea occurred to me that it might be possible to construct the same tail geometry out of 4130 tubing, or even Carbon Fibre tubing. Certainly the CF tubing option would weigh less, but right now I don't really know much else.

Specifically:
(1) What OD/wall thickness of CF tube would be required to give similar strength as 2"x2" 6061?
(2) Similarly, comparitive dimensions for 4130 tubing.

Is there a web site I could visit for these comparative figures? Or does anyone of the forum know the answer?

Kind regards,
Duncan

The carbon fiber strength varies according to the type of carbon fiber, the weave, the efficiency of the molding etc and the type of resin (all these things will also affect the weight). I would imagine it would be rather complicated to narrow all these variables down to get exact figures; almost easier to make a test piece and stress test it.

[Buck]

Remember that like aluminium (<---this is the right way to spell it by the way ), titanium comes in various grades, welding Ti is a specialist task much like Al, working with it is much like high grade steel.

[Doug Riley]

I surmise that how one spells "aluminum" depends upon who one's neighbours are, or perhaps upon the colour of one's money. A couple hundred years ago, Noah Webster decided that the infant America needed her own way of spelling words, and so he "modernised" a bunch of words in his American dictionary. He thought he was doing us a favour.

What Kevin's referring to is steel's toughness. Brittle stuff like glass and concrete shatter as soon as you bend them past their ability to return to their original shape (beyond their "elastic limit"). Any material that behaves this way quits absorbing energy soon after it deforms permanently.

Steel behaves a bit more like clay. Even after it bends permanently, it stays together and further bending still requires energy. This is toughness. The percentage difference between yield (bending) strength and ultimate (breaking) strength is a measure of toughness.

Toughness is a nice characteristic to have in structures that will tend to "crush" in accidents. The destructive energy of the crash is used up to some extent in bending the steel. This converts this energy into heat. (Note how hot a piece of metal gets when you bend it. That's the energy your muscles got from your lunch, being transferred into the metal, and from there into the air.)

[Buck]

The problem in using Ti in the air frame that any accidental damage may result in invisible micro fractures rather than visible dents or bending, heat treated aluminium is generally a better solution for this kind of application or of course the welders favourite, steel.