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Physics, Astronomy & Cosmology / Can a magnet lose its attraction through heating?

« on: 20/07/2009 03:57:01 »

many ways to destroy the magnetism of a magnet.
Heat,shock,and other magnetic field force...
Any ways can change the structure of electrons can destroy the magnetism of a magnet as I know.

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Physics, Astronomy & Cosmology / What would happen when we heat magnet ?

« on: 20/07/2009 03:50:01 »

I works in an ALnico producer company.
I can tell you a little about when we heat an Alnico magnets in a vacuum furnace or a high pressure furnace.
First the high temperature will make the Alnico magnet lose magnetic property first,about 550 degree,and then if you cold it at this point,you will find there should be very little magnetic property.But if you go on heating it,about 1300 degree,(we heat them with ragular way,and the different material we have different ragular way,we control the time and the temperature) the magnets should have same magnetic propety as before,or will be higher magentism.That decide by the technique.
We are famous in China that we always produces some different Alnico material have higher magnetic properties.That is decided by our new technique on element percent and heat treatment.

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Physics, Astronomy & Cosmology / If a magnet loses its property on heating than why Sun don't lose property ?

« on: 20/07/2009 03:32:00 »

Before answer the question,we need to know,why there is magnetism around the permanent magnets and Sun.They seems different,but I think there should be some similar or same point.
As I know,as a person works in a magnets manufacturer company,we know when the environment temperature reach a point,we called Curie temperature,they will lose property,but we never think why?
But we can know a little,when produce magnets,or produce metal alloys,we will heat treat them,and this heat treatment temperature is very high.Why after this process,some alloy will get their magnetic property,but some not?
That is very easy to know that the structure is the reason why some have magnetic property,but some not.
That is the same reason why permanent magnets lose their property,they are easy to change the structure when the temperature reach a point,but sun have different structure by the H and other electrons...