What is the Magnetic Saturation of Cemented Carbide?

Tungsten Carbide/Cemented Carbide is a kind of alloy material produced by powder metallurgy process, injection molding technology or 3D printing process, which takes one or several refractory metal carbide powders, such as tungsten carbide powder and niobium carbide powder, as the hard phase, cobalt, nickel and other metal powders as the bonding phase, and has magnetic saturation characteristics in addition to coercive magnetic properties.

Magnetic saturation of cemented carbides is a physical property of cemented carbides, which can comprehensively reflect the small changes in alloy structure, changes in carbon content, tungsten carbide grain size and grain size distribution, and can be expressed in an accurate quantitative relationship.

The main reason why cemented carbide has magnetic saturation is that the alloy contains ferromagnetic cobalt (Co). Cobalt is a transition metal element. The unit cell is a closely packed hexagonal unit cell. It is located in the fourth period and the eighth group in the periodic table. The atomic number is 27, the atomic weight is 58.93, the electronic arrangement [Ar] is 3d74s2, the atomic radius is 125pm, and the specific gravity is 8.9g/cm3. It has ferromagnetism. When heated to 1150 ℃, the magnetism will disappear.

The research shows that the origin of spontaneous magnetization of ferromagnetic matter is the atomic (positive ion) magnetic moment, and the electron spin magnetic moment plays a major role in the atomic magnetic moment. Like the paramagnetism of the atom, three vacancies in the 3d state of the cobalt atom is a necessary condition for the ferromagnetism of the metal cobalt, but not a sufficient condition. The second condition for cobalt to form ferromagnetism is that the bonding between atoms is beneficial to the formation of ferromagnetism when forming crystals.

The magnetic saturation of cemented carbide can be detected with a cobalt magnetic measuring instrument. The detection principle is: after the tested sample is fully magnetized to saturation in a uniform magnetic field composed of strong permanent magnetic materials, the sample is quickly extracted from the magnetic gap of the magnetic induction signal detection coil. At this time, the size of the magnetic induction signal and the quality of the tested sample are input into the microcomputer for data processing, and the required magnetic parameter values are displayed.