drawbacks of titanium?

Lets see some fancy math - can anyone do the beam bending calculation? This would take into consideration the modulus of elasticity, which is the principal difference between the two metals.
BTW - Modulus of elasticity is the relationship between stress and strain in a given material - ie if you strain a certain material, what stress will develop. Fortunately, steel has one of the highest values among the various metals.
 
Wow, I thought I was a nerd. You guys win. Just to add fuel to the fire, bicycles mfgrs brag about Ti components, and charge astronomical $$ for them. The consensus amongst experienced riders is that yes they are cheaper, but they are not a durable as steel.

IMHO, I think that it is the brag/bling factor that is the big selling point for Ti in rifles. Having said that, we all love our brag/bling, otherwise we'd all shoot 30-06's and drive econoboxes.... so those of you who love the Ti, carry on!
 
If you want to go the beam bending route, it's very simple. I doesn't matter which case of beam bending you take (simply supported with concentrated load, cantilivered with uniform load etc...) if you take two IDENTICAL beams of Ti and Steel the only factor differentiating the two is the modulus of elasticity as stated above.

So whatever case you take, since the modulus of Steel is twice that of pure Ti, the deflection at the point where the load is applied for Ti will be twice the deflection for Steel. In other words, if you take two identical bars made of steel and Ti and you fix them at both ends and place weights in the middle, the Titanium bar will have dropped twice the distance of the steel. Theres no need in doing the math steel is has twice the stiffness of pure Ti.
 
Yes of course - see my diving board example in a previous post - didnt want to scare anyone off with " cantilever beam" Now behaviour under dynamic analysis is another story.
 
manbearpig said:
ive been looking at the titanium rifles lately, and im wondering what the trade-off might be for the reduced weight.

the lighter weight definitely appeals to me -- but not if it sacrifices durability.
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I think the question is answered here, Ti is not as durable as steel, twice as flexible, and some say cheaper.

What was the benefit of a Ti reciever again???:confused: Oh yeah, 4oz lighter and it will relieve you of that extra $500 in your pocket.:)
 
yeah i think ill pass.

when i meant durability, i meant wear/spalling resistance primarily. im not questioning its actual strength as a receiver material as a company with as huge a market like remington would be committing suicide releasing a receiver made of an inadequate material that could catastrophically fail. im sure they tested that part of it thoroughly, im just worried about longterm wear.

really my only non-scientific experience with titanium is in my hiking gear, which is probably nowhere near as strong an alloy as that used in receivers... however i have noticed an alarming amount of wear/chipping/spalling around sharp edges - much more than my stainless stuff. theyre all packed in a way they dont clink around, so this is mostly from washing & drying them alongside other tools and utensils, etc. really its the only thing that made me question titanium as an 'uber' receiver material.
if titanium is showing accelerated wear compared to steel in mere utensils, how would this manifest on bolt lugs/body on receiver wear over a long period of time?

simply from what i have seen in titanium utensils, it wears noticeably faster than stainless steel. have the gun manufacturers directly addressed this with some specialized titanium alloy, or will this actually mean a titanium gun will wear faster than a steel one?

titanium guns havent been around for very long so i cant exactly go and look at a 30 year old titanium receiver and see how its holding up. i can, however, see over 100 year old steel ones. lets face it, if you are spending this much money on a gun you arent just buying it for a year but for a long-term investment, and to pass on to your kids. if long-term wear is affected to simply save 4 ounces then its not worth it for me.
 
Hi i had a titanium rifle in 7mm08 it was very accurate and smooth to shoot. had it out to the range a few weeks ago and found the bolt body was cracked near the handle. Talked to remington and was told to send it to reliable sports in vancouver. To make a long story short am getting one of the new very expensive titanium rifles. hope it shoots as well as the last one but lasts a little longer. they are half a pound heavier so maybe that is the answer. i believe it is just the reciever that is titanium the bolt is fluted stainless steel and the barrel is also stainless. i think the biggest weight saving is the barrel and stock. the bolt felt as heavy as one of my other remingtons. i never weighed the rifle or components. i just know that everyone that picked it up almost threw it through the ceiling thinking it was heavier. i have also played with and shot the browning. not as smooth an action but just as accurate. they sleave the bolt with plastic or aluminum. don not like plastic or aluminum in the action. Kevin.
 
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cosmic said:
Lets see some fancy math - can anyone do the beam bending calculation? This would take into consideration the modulus of elasticity, which is the principal difference between the two metals.
BTW - Modulus of elasticity is the relationship between stress and strain in a given material - ie if you strain a certain material, what stress will develop. Fortunately, steel has one of the highest values among the various metals.
Click to expand...


If you want to go the beam bending route, it's very simple. I doesn't matter which case of beam bending you take (simply supported with concentrated load, cantilivered with uniform load etc...) if you take two IDENTICAL beams of Ti and Steel the only factor differentiating the two is the modulus of elasticity as stated above.

So whatever case you take, since the modulus of Steel is twice that of pure Ti, the deflection at the point where the load is applied for Ti will be twice the deflection for Steel. In other words, if you take two identical bars made of steel and Ti and you fix them at both ends and place weights in the middle, the Titanium bar will have dropped twice the distance of the steel. Theres no need in doing the math steel is has twice the stiffness of pure Ti.
Click to expand...

Sorry Ive been away didnt get a chance to respond till now. Your assertion that Youngs Modulus is the most important factor here is incorrect. My example above is only to demonstrate the fallacy of the above graphic. In order for the above statement to be true that a steel section with approximately a 1/4 of the cross sectional area of the Ti section would be able to carry the same load is false.

Yes pure titanium is weaker than a lot of steel alloys. I was assuming we were speaking of alloys since steel itself is an alloy and I think you would be hard pressed to find an application using pure Ti outside of something extremely specialized. It is also I think safe to assume that the Ti used on this fellows rifle would also be an alloy.

Now lets look at an important equation. The simple equation for Hoop stress. (for thin wall PVs)

Sigma = Pr/t
Where sigma is the stress
P= pressure
r= radius to the inside of the wall
t= wall thickness

So one need only stay below the Yield strength as divided by your factor of safety. The most important factor here is the Tensile strength of the material with Hardness likely coming in second. Hardness being the factor that will influence durability the most.

The modulus of Elasticity really only determines the elastic deformation of the material under loading. I should think that the neck of the brass case will deform enough to ensure that this is of no concern in the chamber. In no way does the Modulus of Elasticity determine how much load a material may carry.

Now if you want to make an argument that the MoE can affect the harmonics of the barrel so be it. Im not getting into that one.
 
My comment wasnt specific to the graphic - I didnt take time to look at it closely, as "equal strength" is ambiguous, as you demonstrated. My concern simply relates to the fact that Ti will strain twice as much as steel under the same applied stress. I would think that rigidity, or less flex, would be a desireable property in an action/barrel, all other factors being equal (geometry,allowable stress, Brinell, nil-ductility temp, etc...) And, no question, Ti compares favourably to steel in yield strength - its Scarecrow that thinks otherwise.
BTW - Take the time to do the Lame equations for a barrel - you'll be surprised at the very low factor of safety - no where near the ASME PV codes.
 
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cosmic said:
My comment wasnt specific to the graphic - I didnt take time to look at it closely, as "equal strength" is ambiguous, as you demonstrated. My concern simply relates to the fact that Ti will strain twice as much as steel under the same applied stress. I would think that rigidity, or less flex, would be a desireable property in an action/barrel, all other factors being equal (geometry,allowable stress, Brinell, nil-ductility temp, etc...) And, no question, Ti compares favourably to steel in yield strength - its Scarecrow that thinks otherwise.
BTW - Take the time to do the Lame equations for a barrel - you'll be surprised at the very low factor of safety - no where near the ASME PV codes.
Click to expand...


My apollogies I misinterpreted. You are absolutely correct though; all things being equal a high modulus of elasticity would be favourable in this application.
 
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