Coefficient of Thermal Expansion for Aluminum 2

[JonWade]

I am looking for formulas and advice for heating an aliminum tube to allow S.S. journals to be inserted producing a shrink fit. I want to calculate the proper sizing if each item as well as the temp. needed for this operation to work properly.
Any help would be greatly appreciated.
Thanks JonWade

 

[swall]

What aluminum alloy and heat treat condition are you working with? This will limit how hot you can heat the aluminum. For dimensional allowances for interference fits, check in Machinery's Handbook or a Mark's engineering handbook.

 

[JonWade]

I am working with 6061-T6 Aluminum seamless tube and 303 Stainless for the journals.
I looked in the Machinery's Handbook, but didn't see any info. on the Coefficient of Expansion for Aluminum. There was info for other materials, but not Aluminum. Do you have any specifics to find it.

 

[IFRs]

The Aluminum Associtaion Design Manual lists the thermal expansion of aluminum as 13.0 x E-6 in/in/DegF

 

[IFRs]

Sorry - make that 13.1 E-5 for 6061 in/in/DegF

 

[ivymike]

matweb is a good place to look for this sort of info, too.

 

[NickE]

CAREFUL!

T6 is the perfect aged version of 6061. Dont over heat or you'll loose strength.

 

[sreid]

Also be careful how much interference you use. When the Aluminum cools the hoop stress can go high enough to cause the Aluminum tubing to split. Especially with steel journals.

 

[swall]

The ageing temperature for 6061-T6 is 350F. So, you won't be able to heat the tubing any hotter. Might have to cool the SS journals is dry ice as well.

 

[kenvlach]

IFRs was right the first time.

"Typical Thermal Properties of Various Metals,"
Machinery's Handbook, 25th edn., p. 369:
Coef. of Expansion, [α], [µ]in./in.-^oF
6061 Al: 13.0
303 SS: 9.6

 

[IFRs]

Again, I'm sorry - it's 13.1 E-6 . I meant to correct the 13.0 to 13.1 and mis-typed -5 instead of -6.

 

[DReimer]

What's an order of magnitude between friends?

 

[WhiteTiger]

My old 21st edition MH gives a figure of 0.00001244 linear expansion per unit length per degree F for aluminum.

Seemed worth mentioning since it offers a slightly different solution path.

 

[IFRs]

I used The Aluminum Association Data Book. If it is critical, perhaps measuring your sample is in order?