磁性是怎麼來的？一口氣了解「磁鐵」

Hello fellow producers You must have heard of magnets But do you know how many things around you use magnets? From the drivers in headphones to the generators in power plants. From floppy disks to hard disks, from 4WD cars to Teslas. From microwave ovens to MRIs. to the magnets in your refrigerator, it's the same principle. Today, let's take a look at the black technology of magnets. Let's get some subscribers for us first, please! Let's get some subscribers for us first, please! The earliest documented use of magnets dates back to 600 B.C. It is mentioned in the writings of the philosopher Thales The origin of the English name of the magnet: a stone from Magnesia. On the Asian side, it is mentioned in the writings of Guigu Zi in 400 BC. 其察言也 "We scout each other's words as surely as we use a magnet to pick up a needle or a tongue to get at the flesh on a charred bone." It's also referred to in some literature as "the gentle stone" And his creator, we call him "the gentle mother”.(It’s kidding) The earliest application of the stone was the "compass." In addition to guiding the way, it was also used to search for water or minerals and the gentle mother (absolutely kidding). Around the 12th century,the big pirate time began(it's kidding). Jumping back to the early 19th century in Denmark Hans Christian Orsted, a university professor in Copenhagen Accidentally discovered that an electrified coil could affect the compass needle. Humans began to study electromagnetism Later, motors, generators, telegraphs, radios, stereos, televisions, and even medical equipment were all developed. So, how exactly does the magnetism of a magnet work? As we learned in high school, all objects in the world are composed of atoms, which are made up of electrons, protons and neutrons. Electrons and protons are charged, and the movement of electrons within an atom is a bit more active. In addition to running around the nucleus of the atom, the electrons are also constantly spinning, which is called electron spin. And because the movement of charges creates a magnetic field, the spin makes the electrons themselves magnetic like little magnets, so in effect the nucleus of an atom is surrounded by many little magnets. But most elements carry a paired number of electrons. The magnetic field generated will cancel out and make that element non-magnetic. If it has unpaired electrons, then the magnetic field that isn't canceled out will make the element magnetic. These are the only elements in the table of elements that are magnetic. However, the combination of magnetic elements does not mean that the substance is magnetic. As we mentioned in the heat treatment program. During the stacking process, the atoms will have their own little circles. Each little circle may have a different direction of the magnetic field. When the magnetic field is stronger in a certain direction, the overall magnetic field will be biased in one direction, which will further enhance the magnetic properties. This is how natural magnets are magnetized. On the other hand, when the circles are all about the same size and have their own direction, the magnetic forces will cancel each other out. and there will be no effective magnetism. At this point, if we apply a strong magnetic field outside, we call it the KOL magnetic field.(just kidding) so that they slowly point in the same direction and amplify the magnetic field, which is called "magnetization". However, it is not so easy to change the direction of the small circles, and in general, it takes a super strong magnetic field to change the direction. Luckily, we have discovered a few tricks to penetrate the field of the small circles: applying energy from the outside can help us magnetize them more efficiently. One way is to use tapping. The "shock" of tapping on a magnetic material causes the molecules to become active and the magnetic field to loosen, making them more susceptible to external magnetic influences. This is the same principle that temporarily turns a nail into a small magnet when we hammer it. Iron nails are magnetized by geomagnetism. But by striking them. Because the vibration is not very even, so the small circles will gradually return to the non-magnetic state. The second is "heating". The magnetic material is heated to a specific temperature point, called the "Curie Temperature", which varies depending on the material, and is usually around 700-800 degrees. At this point, the molecules become active due to the heat energy, and the internal magnetic field becomes relaxed. The KOL magnetic field can be more easily media framing.(It’s kidding) Then, when the temperature drops, the magnetism will be fixed, which is a better way to magnetize than tapping. By changing the magnetic field into a more orderly one, the magnetic force becomes stronger, like being charged, so this is also called "magnetization". In the industrial production of magnets, the magnetic material is heated to the Curie temperature, then slowly cooled down to achieve "demagnetization" (or demagnetization), and then externally "magnetized" with a magnetic field applied by an electromagnetic coil, so that the magnet becomes magnetic. A magnet that retains its magnetic force after magnetization is called a "permanent magnet", which is the type of magnet we generally know as a hard magnet. In fact, there are more types of permanent magnets than you think, the main difference is in the strength of the magnetic force and the degree of temperature resistance. Because the working temperature of each type of magnet is not the same, over the working temperature of the magnetic force will begin to weaken, if over the Curie temperature, will be completely demagnetized! Therefore, it also affects the field of application, not the magnetic force is strong enough to be able to do all the work. The black magnets we often see on whiteboards are "ferrite magnets" the main component of which is iron oxide, a ceramic material that is used in household speakers, motors, and microwave ovens, which is cheap and easy to use, with the disadvantage that it is commonplace and fragile. Next up, "AlNiCo magnets." Is the first to be developed magnet materials, most of the applications have been replaced, but because of the temperature change on the magnetic force is very low, Currently commonly used in special industrial or military applications. NdFeB(Neodymium) Magnet It is the kind of powerful magnet sold in stationery stores, which can lift up a thousand times its own weight, and is currently the strongest magnet, known as the Magnet King, which is used in strange experiments on the Internet. However, this kind of magnet is easy to be corroded and oxidized, so the surface needs to be protected by electroplating, which is more suitable for consumer products, which is more suitable for consumer products, such as hard drives, cell phones, headphones, high-end stereos and even motors of electric cars. Neodymium securities is a rare earth element, and some posh have heavy rare earths such as Dy and Tb added to them, which makes them a bit more expensive. There's also a high-grade, powerful magnet. It's called "Samarium Cobalt". Although the magnetic force is only the second strongest, but the working temperature is higher than NdFeB Magnet, there is also a strong corrosion and oxidation resistance, such as the aerospace, fuel car in the Sensor, hydrogen car compressor and so on. Sm and cobalt are also rare earth elements, so they are more expensive. Magnetic powder can also be mixed with rubber or resin materials to make "flexible magnets" or "rubber magnets", which can be processed by common processing methods for plastics, such as injection, molding, extrusion, etc., to eliminate the disadvantage of fragility of magnets, and soft magnets are also this kind of magnets, and the plasticity will be higher, and the precision will be higher, and it can be lightweight, and it is suitable to be used in the field of fan motors, small motors, and so on. However, if other materials are mixed with the magnet, the magnetic force will be weakened. The opposite of what we talked about earlier is "non-permanent magnets", that is, magnets that do not retain their magnetic force easily after magnetization and are prone to change their magnetic properties, or called "soft magnets", which are completely unrelated to the soft magnets we talked about just now. Electromagnet is a kind of non-permanent magnet, which is magnetic only when there is electricity, and the stronger the current is, the stronger the magnetism can be, which is often seen in movies. In addition to the coil, the magnet's mechanism must have a soft magnetic material as the core in order to guide and amplify the magnetic field. In addition to magnets, there are also a lot of other things, such as ferromagnetic fluids, spinning magnets and so on, , which are very profound, so we'll talk about it again sometime. In fact because most of the rare earth metal ore sources and separation technology are mastered in China, the majority of magnet manufacturers are also in China. If you're looking for magnets made in Taiwan, you'll have to look no further than "TAIGENE METAL", the sponsor of this issue! "TAIGENE METAL"is currently Taiwan's only magnet supplier with a complete production line from raw materials, processing, sintering, grinding, magnetizing, has a history of 50 years, this is their factory in Longtan, Taoyuan look at this magnet one by one burned out how therapeutic ~ Famous audio brands such as ＯＯ, ＯＯＯ, and ＯＯＯＯ are all their customers, and they can be said to be the leader of magnets in Taiwan! End of Sales Presentation Thank you, sponsor. In fact, we are like magnets. When we are aroused by the excitement of the crowd, we will be easily swayed. Just as we need to be warmed up before we are magnetized, so brainwashing will give us a period of sensory stimulation first. It is possible to change our minds by filling them with information. So whether it's money or love, we still need to remember to stay partially calm So that we won't be abducted. Speaking of which, I also want to have a big magnetic field to attract fans! That's all for today, see you in the next time.