A permanent magnet is a material that can
provide magnetic flux when magnetized with an applied magnetic field and its
magnetism capability is characterized by two key parameters: remanence and
In general, the intrinsic coercitivity of a
permanent magnet (Hcj ) is greater than 300kOe (in the CGS unit) or 24kA / m (in
the SI unit). With greater coercitivity, a permanent magnet has a greater
capacity to resist demagnetization, including electric or magnetic circuit
field demagnetization and thermal demagnetization of the working temperature in
various motors and/or electrical machine applications.
A commercial permanent magnet requires
relatively high remanence and coercion at an affordable cost and, in contrast
to an electromagnet, the latter only behaves like a magnet when an electric
current flows through it.
materials is a permanent magnet made of?
As for the types of materials, permanent
magnets manufacture with hard ferromagnetic materials, which are those that,
after being magnetized, maintain their magnetic properties until they are
demagentized, which is the phenomenon that occurs when applying a magnetic
field contrary to that of the beginning.
The materials used for the manufacture of a
permanent magnet are:
The alloy of neodymium, iron and boron is used for the manufacture of the well-known NdFeB, NIB and Neo.
It is the alloy of aluminium, nickel and cobalt and sometimes copper, iron and titanium are used.
Cobalt-Samarium. As its name suggests, it is made from the alloy of samarium and cobalt.
On the other hand, permanent magnets are made
of natural substances such as magnetite (Fe 3 O 4 ), the most magnetic natural
mineral. The Earth itself is a large permanent magnet, although its magnetic
field is quite weak in relation to its size. Humans have used Earth's magnetic
field for navigation since the compass was invented in ancient China.
Even the most powerful permanent magnet is not as strong as the strongest electromagnets, so their applications are limited, but they still have many uses such as neodymium magnet applications in electric motors. The more mundane would be used as refrigerator magnets, but magnets can be found everywhere, including:
In fact, electric motors operate through an
interaction between an electromagnet and a permanent magnet.
How does a
permanent magnet work?
Each permanent magnet generates a magnetic
field, like any other magnet, which circulates around the magnet in a different
pattern. The size of the magnetic field is related to the size of the magnet
and its strength. The easiest way to see a magnetic field generated by a
permanent magnet is to disperse the iron filings around a bar magnet, which are
quickly oriented along the field lines.
Each permanent magnet has two poles, called
north and south, although they could be called A and B. Similar poles repel
each other while opposite poles attract each other. It takes a lot of effort to
keep the repellent poles of a magnet together, while an effort is required to
remove the poles of attraction. The most powerful magnets attract with such
force that they can cause injury by pinching the skin between them.
For thousands of years, permanent magnets
were the only magnets humans had. The electromagnet was only invented in 1823.
Before that, magnets were mostly novelties. Using an electromagnet, it is
possible to induce a current in any ferromagnetic material, such as an iron
clip. However, the effect fades quickly.
At IMA we can advise you on the permanent magnet that best suits your project or need. If you have any questions, please contact us.
Strictly Necessary Cookies
Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings.
If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again.
This website uses the following additional cookies:
(List the cookies that you are using on the website here.)
Please enable Strictly Necessary Cookies first so that we can save your preferences!