Aluminium vs steel contraction when frozen

PRW

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Melbourne, Australia
So, I have a bearing outer ring stuck in a aluminium frame (the swingarm). The bearing has broken, leaving only the outer ring wedged in.

If I put the the swing arm in a freezer - would the aluminium extra contraction make it easy to extract? How brittle would the aluminium become if frozen?

Thanks
 
Aluminum expands much more than steel, when heated. Freezing witll contract the aluminum only to hold the broken race tighter? Try a heat gun or a torch or an iron or something to heat the aluminum . The aluminum will expand (3X) whle the steel will less (2x) and the bearing should come out. Ice on the bearing while heat on the frame might help.
 
the above replies are exactly what I thought, logically - until my wife gave her opinion which confused the hell out of me....

Her view is that when metal expands, all the metal will get bigger - so the hole gets smaller. When the metal freezes, all the metal shrinks, so the hole gets bigger.

My mind now switches between the way I originally thought, when any freezing naturally will tighten the hole... and above.
 
Honestly, it's well known brain-teaser as to whether the hole in a ring gets bigger or smaller when it's heated. The trick is to mentally uncoil the ring into a rod. When you heat a rod it obviously gets much longer than it does thicker and if re-bent into a ring it would have both a larger outside and inside diameter.
 
Punx0r said:
Honestly, it's well known brain-teaser as to whether the hole in a ring gets bigger or smaller when it's heated. The trick is to mentally uncoil the ring into a rod. When you heat a rod it obviously gets much longer than it does thicker and if re-bent into a ring it would have both a larger outside and inside diameter.
Good explanation, PunxOr, thanks - even my wife agrees! 😀
 
Yes, common practice is to heat the “aperture” , and chill the “insert” in order to create clearance.
And heating is much more effective since you can get a much greater temperature differential than simply freezing. ( though dry ice or liquid Nitrogen is also used for some applications !)
 
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