Nd-Fe-B (neodymium iron boron) sintered magnets are essential key components in the drive motors of hybrid and electric vehicles. Compared with other magnets, Neodymium magnet not only has strong magnetic force, which can achieve high power enough to drive vehicles, but also can reduce the motor to the size suitable for vehicle use.

So, do you know how this neodymium iron boron strong magnet was manufactured? It requires first crushing the alloy containing the necessary materials into particles, aggregating these particles to form, and then sintering them. Afterwards, it can be cut to the required size to complete. This process always feels like making a cake.

Of course, in actual mass production of high-quality neodymium iron boron strong magnets, it is not so simple. Not only do we need to unify the particles into 3-5 μ The size of m, and attention should also be paid to the uniformity of shape, as well as the heating method during sintering, which requires a lot of effort to manufacture. "It is only through the accumulation of a large number of small technologies that we have reached today's practical level" (technicians engaged in the development of Neodymium magnet).

For example, crushing the alloy to 3-5 μ One of them is the "forming process in the magnetic field" implemented after m. This process is to orient the crushed micro powder (micro magnet). The orientation here refers to unifying the magnetization direction of the micro powder into a fixed direction. The higher the orientation, the greater the residual magnetic flux density (an indicator of magnetic field strength). When implementing this process, the micro powder is first filled into the mold, and a strengthened magnetic field is applied to orient the micro powder, followed by pressure forming treatment. The uniqueness of this is that it is gently pressurized to the extent that the formed body will not collapse. Because if the pressure is too high, it will actually disrupt the finally unified micro powder orientation.

To achieve high orientation, it is also important to create a space with a uniform magnetic field inside the mold. Due to the configuration of the electromagnet and the size, shape, and material of the mold, the magnetic field is uneven, resulting in poor orientation. Therefore, it is necessary to use magnetic field analysis and other means to make fine adjustments to make the magnetic field uniform.