Alnico Magnets: What are they? If you ever had a horseshoe magnet as a child then you probably owned a Alnico Magnet. If you need a magnet to retain it’s magnetism at high heat then you just may need an Alnico Magnet! Alnico Magnets are strong permanent magnets, although they are not as strong as the more commonly available rare earth magnets like neodymium and samarium cobalt. Yet these alnico magnets can keep their working magnetism up to around 1000° Fahrenheit. Thats right these magnets will usually still stay magnetic even though they are RED HOT! You would have to heat this magnet above 1470° before it will lose it’s permanent magnetic properties. Also these magnets unlike ceramic magnets, will conduct electricity. If handled properly these magnets stay very stable. So where does that name come from Alnico”? it is an acronym for a type of an iron alloy. Since it is an Iron Alloy, Iron of course is the main ingredient. In addition to Iron this alloy contains Aluminum, Nickel and Cobalt. So if you put their periodic symbols together you get Al-Ni-Co, there you go Alnico! This alloy may contain small amounts of copper and titanium. This type of magnet is produced by casting or by heating powdered metals at very high melting temperatures and then cast into molds. To get the magnetic properties this alloy is heated above a certain critical temperature and then is cooled within a strong magnetic field. One strange use for an Alnico Magnet is what is called a “Cow Magnet.” Normally they are bullet shaped about 3/8” diameter and about 3 inches long. This cow magnet is usually fed to the cow at branding time with their feed. These magnets then will lodge in either the cow’s first or second stomach. Now cows are not as intelligent as they look to be so when they feed or graze they are not that particular what goes down their throat. They will swallow all kinds of metal, like nails, pieces of barb wire, bailing wire, staples, etc. Without this magnet these pieces of iron could cause harm to the animal as small pieces travel through rest of the animal’s digestive tract, or these sharp metal objects could actually penetrate the animals tissues and cause infections. The cow magnet traps all these iron particles and keeps them safely trapped in the first or second stomach for the life of the animal and all stuck together in one large lump. Other common uses for Alnico magnets are with electric motors and sound equipment. So next time you are at one of your favorite concerts and you have a little time to distract yourself from the music think about the place these magnets can be found. That microphone, the loudspeakers, the amplifier speakers and that electric guitar being played all might just have Alnico magnets within them. Although many of these items are now using the stronger and smaller neodymium magnets.
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