Nanoparticles refer to particles with a particle size between 1-100nm (nanoparticles are also called ultrafine particles). It belongs to the category of colloidal particle size. They are in the transition zone between clusters of atoms and macroscopic objects, between the microscopic system and the macroscopic system. They are groups composed of a small number of atoms or molecules, so they are neither typical microscopic systems nor typical macroscopic systems.
There are many applications in magnetic materials, for example: Nano particles can be used as permanent magnet materials, magnetic recording materials and magnetic fluid materials.
The nanoparticle volume effect enables materials that are usually sintered at high temperatures, such as SiC, WC, BC, etc., to be sintered at a relatively low temperature in the nanometer state to obtain a high-density sintered body.
On the other hand, because nanoparticles have the sintering characteristics of low-temperature sintering, high fluidity, and large sintering shrinkage, they can be used as an active agent in the sintering process to accelerate the sintering process, reduce the sintering temperature, and shorten the sintering time. For example, ordinary tungsten wire powder must be sintered at a high temperature of 3000 ℃, and after adding 0.1 to 0.5% of nano-nickel powder, the sintering temperature can be reduced to 1200 to 1311 ℃.