Alnico permanent magnet material is the earliest widely used permanent magnet material, and its preparation process and technology are relatively mature.
The level of development
The preparation process and performance level of AlNiCo permanent magnet materials at home and abroad are basically the same. Due to its special properties and habitual use in instruments and meters, there are factories in Japan, the United States, Europe, Russia, and China.
Production scale
In China, some research units and factories engaged in machinery, instrumentation and aerospace industries often carry out small-scale supporting production in order to meet their own needs. Among the large-scale production enterprises, the output of Hangzhou Permanent Magnet is currently the largest in China, with an annual production capacity of 3,000 tons (Hangzhou Permanent Magnet is also one of the suppliers settled on the magnetic e-buy platform).
Material characteristics
The residual magnetic flux density of this material is high, up to 1.35 T, but their intrinsic coercive force is very low, usually less than 160 kA/m, its demagnetization curve is nonlinear, and the AlNiCo permanent magnet The return line does not coincide with the demagnetization curve, so special attention should be paid to its particularity when designing and manufacturing the magnetic circuit of the device, and the permanent magnet must be stabilized in advance.
According to the low coercive force of AlNiCo permanent magnet material, it is strictly forbidden to contact with any ferromagnetic objects during use, so as not to cause local irreversible demagnetization or distortion of magnetic flux density distribution.
In addition, in order to enhance its anti-demagnetization ability, the pole surface of AlNiCo permanent magnet is often designed as a long cylinder or a long rod.
In addition, AlNiCo permanent magnet materials have low mechanical strength, high hardness, brittleness, and poor machinability, so they cannot be designed as structural parts, and only a small amount of grinding or EDM can be used for processing, and forging cannot be used. and other machining.
Application field
The magnetic properties of AlNiCo change little with temperature, and it is still widely used in permanent magnet devices requiring high temperature stability, such as instruments and meters and motors. It is especially suitable for use in weapons and equipment such as torpedoes, missiles, and aircraft, and spacecraft such as satellites.
