Coeficient of Friction (titanium)

[jjagodni]

I am looking for the coeficient of friction for 6Al4V titanium on 6Al4V titanium annealed (both static and dynamic). I have not been able to find it anywhere (matweb, Marks handbook, Titanium books...) If you know where I could find this, or any other titanium on titanium coef. of friction, it would be greatly appreciated.

 

[tedg]

Have you tried the International Titanium Association at

http://www.titanium.org

 

[jjagodni]

Thank you,

I posted a thread on that site, however I haven't heard anything yet. I was able to find the coef. of friction for 6al4v on 1080 steel from another source.

 

The coefficient of friction is a system property, not a material property. It is dependant on many factors such as material, counter-material, lubrication, temperature, speed, loading force, surface finish, surface finish of the counter-material, and type of motion (reciprocating, rotating). Published values can have large variations.

Published values range from 0.05 to 0.90.

 

[Ron]

JJ..Malygris is correct, though materials properties affect the result due to localized malleability of the mating surfaces (theoretically independent of that, but not in practicality). The static coefficient is very easy to determine by testing. Stabilize one piece so that it cannot move. Place the other piece on top of it and apply a weight of, say, 50 lbs. This will be the normal force. Then measure the amount of force required to just move the top piece in a lateral direction. Fundamentally, the coefficient of friction is the force required to move the load divided by the normal force. The amount of weight you use for the normal force is not important. The result should be the same over a range of weights, unless you apply enough weight to actually deform the mating surfaces.

Ron

 

What if I have a poxy paint on both parts (a box and a bed tray where the box rests) I know the weight of my box is 60 pounds and I would like to know the force I need to apply in order for two man to drag the box and remove it from its bed tray. I know force equals weight times coeficient of friction, how do I determine my coeficient of friction? THANKS!

 

[Ron]

F=Nf, where F=horizontal force required to overcome static friction, N=force or mass normal to the horizontal plane, and f=coefficient of static friction....so the answer to your question is f=F/N

 

Ron, thanks for your response. I do understand the equation, what I do not understand is how to get the "F" "horizontal force required to overcome static friction". Is this number given depending on the situation or do I have to experiment to get the number? Thansk a lot!

 

[Ron]

It is empirical...you can use a fish scale (or get fancy and use a dynamometer) and measure the force required. If the item you want to move is very heavy, you can do the test with a lighter weight (obviously as long as you use the lighter weight in your equation!). The static coefficient of friction is (theoretically!) independent of the weight (mass) of the object.