Neodymium Magnet Durability: Retention of Magnetic Properties, Forced Connection, Impact Effects

Hello

I would like to know how long does a neodymium magnet retain its magnetic properties? Ie. Let us assume such a purely hypothetical situation that we put a neodymium magnet on the table for an infinitely long time in a room (room conditions) - do we know after what time it will demagnetize "by itself"? or will it demagnetize at all?
What happens if two neodymium magnets are forcibly connected (e.g. in a vice) with the same poles and left for a long time (e.g. infinitely long) - are they demagnetized, or will they retain their magnetic properties anyway?
is it true that a magnet that falls to the ground loses a fraction of its properties, and if you throw it several times, it will degauss completely?
What can demagnetize a neodymium magnet?

Regards

If it loses its properties after a fall - it is likely to break - it is usually a sinter or a suspension of metal powders in the glass. I also heard that heating above 100 -150 degrees causes partial or complete demagnetization, I have never checked it, so I will never confirm it. As for the degaussing itself, I don't have any information about it.

I don't know what it looks like with degaussing over time, probably similar to the half-life of radioactive elements - calculable but not to be checked. cuir'e point

It certainly demagnetizes after exceeding the Curie temperature, which for neodymium magnets is over 300 ° C. http://pl.wikipedia.org/wiki/Temperatura_Curie
But just how is it with the situation described in the first post?
Anyone know?

unblack wrote:

Hello

I would like to know how long does a neodymium magnet retain its magnetic properties? Ie. Let us assume such a purely hypothetical situation that we put a neodymium magnet on the table for an infinitely long time in a room (room conditions) - do we know after what time it will demagnetize "by itself"? or will it demagnetize at all?
What happens if two neodymium magnets are forcibly connected (e.g. in a vice) with the same poles and left for a long time (e.g. infinitely long) - are they demagnetized, or will they retain their magnetic properties anyway?
is it true that a magnet that falls to the ground loses a fraction of its properties, and if you throw it several times, it will degauss completely?
What can demagnetize a neodymium magnet?

Regards

I'm sitting in neodymium so I was collecting a lot of information.

Estimated by the manufacturers (pioneers in the construction of these magnets), the time to lose half the magnetization is about 30 years. The total loss of properties is about 100 years.
I do not know on what basis they calculated it (? Approximation based on several months of research)

A violent shock (fall without even damage) also causes a loss of 'power'. Safe temp for neodymium is 80-100C.

Regards,

Well, these are satisfactory values if you believe them, but what is the durability if the magnet "works", ie if something attracts or repels. Has anyone tested it? Or maybe it can be calculated theoretically, for example, if two identical magnets are glued together with identical poles.
And who is the "pioneer in the construction of these magnets" if you can ask?

In 1982, General Motors, Sumitomo Special Metals and The China Academy of Sciences independently discovered Nd2Fe14B - a component of neodymium magnets.

Well, yes, but not entirely. The force of the magnetic interaction is not the energy that is somehow stored in the magnet and goes out, so it only "exhausts" a certain property of the material, resulting from a specific arrangement of atoms. Thus, a permanent magnet "demagnetizes" or loses its magnetic properties as its atoms exit from this fixed system. This happens at a different rate depending on the type of magnet. For example, the permanent magnet magnetization of a steel screwdriver can fade to below a noticeable or practical level within minutes or hours. The neodymium magnet loses its properties at a rate of approx. 1% within approx. 10 years (thus it can be assumed that even the cheapest neodymium magnets will undergo chemical erosion much faster, for example, than they self-demagnetize). Of course, we are talking about favorable conditions - as it was rightly noted above, each permanent magnet has a thermal threshold above which demagnetization will occur suddenly, permanently and completely (therefore, for example, if you want to neutralize a magnetic storage medium, it is best to heat it strongly, e.g. a hard disk to a heated furnace furnace, or for a few moments under a workshop burner). In addition, neodymium-iron-boron magnets have already been produced, for which no measurable loss of magnetic properties has been observed over time, so for all practical purposes they were considered eternal (you know, nothing is eternal, but if something usable retains its properties) for e.g. millions of years, such a simplification can be accepted).