Magnet Info – Page 8 – Magnet Fishing Adventure

Magnets are a fascinating topic. Taking advantage of an invisible field magnets can attract or repel other ferromagnetic materials as if they were magic. Of course, the principles behind magnets are well known and heavily researched by now, but there's no denying the sheer appeal of magnetism and how much it impressed us when we first saw it in action. Nowadays magnets are everywhere even if we don't notice them. The hard disks of our PCs use magnets, just like our credit cards, speakers, and microphones. So magnets are both visually impressive and have a lot of practical value. But as we come to rely more and more on magnets it does bring out a question to the forefront, do magnets wear out and how long do they last? After all, if we need magnets so much we should know the odds of these things losing all power suddenly. Today we'll answer everything we can on the duration of magnets and try to explain what we can do to ensure magnets last longer or get recharged if possible. So keep reading on to discover a whole new side of magnetism. How Long do Magnets Last? Before we ask if magnets can wear out on their own we need to understand why they work in the same place. Magnets rely on the position of their electrons to generate their magnetic field, and one constant in our world is that atoms will move around. What this means is that the position of a magnet's electrons is going to change with time, and this does mean their effectivity as magnets will wear out. Time on its own is more than enough to make a magnet wear out and lose its strength, however just because this is a natural process it doesn't mean it's a fast one. A modern magnet made out of rare earth alloys can last centuries without completely losing its magnetism, which does mean magnets will usually outlast us. The most common magnets on the current market are made of neodymium, and they lose roughly 5% of their magnetism every 100 years. So assuming no other external factors affect its magnetic field, it would take 1000 years for the average modern magnet to lose half of its magnetism. Generally speaking, magnets will lose their efficiency due to factors unrelated to time, as the amount of time they spend under our use is largely insignificant by their standards. Do Magnets Wear Out or Weaken Over Time? All magnets will naturally weaken over time due to the way atoms work. Even if an object appears completely solid things are completely different at an atomic level. A "solid" block of metal is made of countless atoms that not only can change positions but interact with the rest of the world. Even if we ignore possible external factors like heat or blunt force the atoms inside a magnet will start to be affected with time. As time passes the bonds and positions inside a material change. And this means that the ideal alignment of electrons that made a magnet powerful in the first place will start to shift. These shifts aren't noticeable to the naked eye but have long been proved with science. And ultimately this means that even if you handle a magnet perfectly and it never comes into contact with any risk factor, it will still lose magnetism simply due to the passing of time. That said as we mentioned above the natural demagnetization rate of modern magnets is incredibly low. So it would take multiple owners and lifetimes to drain a magnet of its magnetism just due to the passing of time. If anything when our magnets start to wear out and lose power it almost always comes down to other factors beyond time. So your magnets are wearing out more due to use than due to time. What Causes Magnets to Lose their Magnetism? As we've seen so far while time is a possible factor for demagnetization it's rarely the one affecting modern magnets. So what else can cause a magnet to lose its natural magnetism? The first risk factor for magnets is volume loss. Since magnetism is tied to the alignment of electrons over a surface it makes sense that losing part of its volume will reduce its magnetic properties. For example, if your favorite magnet splits in half due to a fall both halves will be considerably weaker than their original counterpart. The energy of the impact alone can affect the internal alignment of a magnet, so you should take care not to drop magnets. Heat is another factor that has a considerable impact on a magnet's performance. The reasoning for this once again comes to all the electrons and particles inside a magnet. When a material is heated its particles start moving at a faster pace. This means that the precise alignment needed for magnetism is no longer there, and the magnet will be weaker as a result. All magnetic materials have a "Curie Point" which determines the maximum temperature they can withstand before they start losing all their magnetism. However, since this point it's usually way above 300°C it's not going to be a factor in daily use. Last but not least other magnetic fields can affect a magnet's efficiency. When exposed to other fields their internal alignment might shift due to the external pull, and as we've seen so far losing that internal alignment is the whole reason why magnetism starts fading. Do all Magnets Wear out? Yes, all magnets will naturally wear out due to the passing of time. While magnetism is a natural process in nature this doesn't mean it's permanent. Regardless of whether you are dealing with a magnet made of Iron, Neodymium or Alnico they will lose magnetism as time passes. That said each material will wear out differently. The natural demagnetization rates of different materials are not the same, nor is their resistance to external factors such as falls and other magnetic fields. For example, in ideal conditions, an Alnico magnet should last as much as a Neodymium one. However, due to their composition Alnico magnets are much more vulnerable to demagnetization. Heat and impacts will cause a considerably sharper decline in efficiency compared to other materials. And this is why some magnets appear to wear out much faster than others. Can Magnets be Recharged? Generally speaking, a magnet can be recharged provided the internal wear it has sustained isn't too severe. In other words, recharging a magnet that broke apart or that lost its alignment might be a futile task. But if the magnet is largely intact and just lost some power then re-magnetization is perfectly possible. Re-magnetization is usually done by exposing a worn-out magnet to another magnet that is considerably stronger to itself. However, you need to take care when doing this as doing it wrong can result in the magnetic field affecting its magnetism further. As we know by now external magnetic fields can wear out a magnet, so you can't just rub two magnets in any direction and recharge them. If anything doing so will likely wear them out further. To recharge your magnet you will need another magnet that is stronger than it and a compass. Use the compass to find out the natural poles of your magnet, the needle will naturally point to the south pole of your magnet so it will be a simple process. Once you have determined the north and south poles of both magnets you can recharge your old magnet by rubbing its poles with the opposite pole of the stronger magnet. This helps realign the magnet and is an effective way to recharge your magnets amongst each other. Conclusion A magnet can last a LONG time In ideal conditions, all magnets in the current market will last for centuries. The materials employed in modern magnets can keep their alignment for years, and since their decay rate is listed by centuries it won't be a problem on its own. However, there are other factors like heat or external magnetic fields that can impact the performance of your magnet. So a magnet's lifespan could decrease depending on how you handle them. Provided you use them responsibly magnets still should be able to survive centuries without losing much magnetism. But sometimes falls and other accidents are unavoidable, and they will impact their life expectancy. Nonetheless, with proper care and occasional recharging, a magnet should be able to last you a lifetime without issue. Sources used: https://en.wikipedia.org/wiki/MagnetDo magnets wear out? - BBC Science Focus MagazineDo Magnets Wear Out & How Long Do Magnets Last? Discover If Magnets Lose Their Power Over Time | Dura Magnetics USADoes magnetism decay over time? | New ScientistHow Long does a Magnet Last - Frequently asked magnet questions (strydomwebdevelopment.co.za)The Pros and Cons of Alnico Magnets | Are Alnico Magnets Right for Your Job? (jobmastermagnets.com)Neodymium magnet - Wikipediahttps://www.imamagnets.com/en/blog/can-magnet-be-remagnetized/