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Cold melt

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Tracmag

Tracmag

Electrical
Nov 8, 2010
7
A copper plate is sandwiched between two nickel plated neo disc magnets. The assembly is spun as one would spin a nickel on a table. After removing the copper plate, it shows multiple spots of pooled metal. The copper and the nickel seemed to be mixed together yet there is no sign of heat present. 5 dimples were made in the copper plate and tissue paper was placed in the dimples in hope of seeing heat transfer, yet there was no sign of it. At these temperatures, should there not have been some heat present? Why is there no heat , is the question.
 
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Is this is a practical engineering question, or looking to explain something you saw on YouTube?
 
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It is something that I have done and would like to find out why it has occured.
 
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So you have a sandwich of two magnets with a copper disk in the middle, and it's being spun as a unit with no relative motion between the parts.

Is it being driven with a motor for minutes or hours? Or just given a spin and allowed to decay, how fast and how heavy?

Any other fixed magnets other than the Earth's?

Are the plates welded together after? Is it spin welding with relative frictional motion?
 
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Correct, no relative motion between the parts. It is being driven by another magnet some distance away. It is at 90 degrees to the driving magnet. I let it spin about 10 minutes before I stopped it. The assembly is held together with grey duct tape and it spins at about 3000 RPM's and rolls much less. The assembly weighs a little over 2.5 lbs. The driving magnet is about 350 times smaller.
 
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Why did you do this experiment in the first place?

You must have some theory or you think that you want to prove something. What is your theory or what is it you want to prove?

Gunnar Englund
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
 
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The parts are not welded together after spin down.
 
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I did it out of curiosity and quite accidentally noticed the effect. I do not have a theory as to why it occurs but am interested in knowing why it happened without any sign of heat.
 
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I am new to eng-tips and am aware that promoting anything is prohibited, so I am reluctant to show a video. I do have a video of the 2lb. disc magnet spinning without the copper plate and additional magnet. It can give one an idea of the speed and orientation of the disc. I would ask that if I directed one to the video, would it be promoting?
 
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If it is blatant advertising, we'll know it when we see it and we'll flag it.

I don't think this thread will go very far without us seeing the video.

My vote is to post the link to the video (as long as you are honestly trying to understand what is going on rather than trying to sell us something).

=====================================
(2B)+(2B)' ?
 
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"It is being driven by another magnet some distance away"

Doesn't that tell the whole story right there? You are inducing varying magnetic fields in the copper with that "another magnet", and those fields cause currents high enough to melt the copper surface slightly.

Look up "induction motors" for an explanation.


Maguffin Microwave wireless design consulting
 
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Given that the metal parts of the assembly are thermally conductive, and given the total amount of energy available (not much), it seems difficult to explain how there could be any significant melting.

"The assembly weighs a little over 2.5 lbs..."
"...spins at about 3000 RPM..."
"...is held together with grey duct tape..."

[spin]

Sounds a bit dangerous.
 
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One metal is "nickel". I think there is such thing as "nickel creep", whereby in electronic circuits, nickel is a scary metal since it forms dendrites and makes short circuits. i.e. nickel is more elastic than most metals.

Maybe you're forming a friction/magnetically induced voltage that is pulling the nickel into the copper?
 
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I would agree with the above, that small spinning magnet is not strong enough to cause eddy currents to flow in the copper that would be large enough to melt anything.


Maguffin Microwave wireless design consulting
 
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