The production process of atomizing spherical metal powder looks simple, but it is not. Most manufacturers do not have technical and scientific personnel, or even skilled operators. In addition, the cultural quality of the workers is low. Most of the workers have high school education or below, lack of practice and innovation spirit, which leads to the research on the properties of spherical metal powder is almost in a blank state.At present, the known basic factors affecting the sphericity and surface finish of atomized spherical metal powder mainly include: atomized gas pressure, atomized gas (nitrogen) temperature, liquid aluminum temperature, atomization system pressure and centrifugal and cyclone classifier design.

The atomization process can be summarized as a two-step breaking process: molten metal and nitrogen converge at the nozzle edge and exchange momentum and heat. The molten metal is destroyed, the greater the pressure, the greater the gas velocity and kinetic energy, and the stronger the interaction between the gas flow and the liquid flow, the stronger the effect, the higher the turbulence in the flow field, the more fully the crushing can be carried out, and the smaller the droplets obtained in the initial atomization; The aluminum droplets obtained during the initial atomization are accelerated by the airflow.

During acceleration, the balance between the aerodynamic forces acting on the spherical metal powder and the surface tension is destroyed, and the droplets are further broken, that is, undergo a secondary atomization. The greater the atomizing pressure, the greater the atomizing airflow speed, the greater the relative velocity between the airflow and the molten spherical metal powder, and the more sufficient the secondary atomization process caused by the velocity difference, so as to obtain more fine powder particles.

In the atomization process, droplets of molten spherical metal powder are broken up and then cooled and solidified into particles during the subsequent flight. The morphology of the particle depends on its deformation during cooling and curing. The droplet will be spherical under the action of surface tension and irregularly deformed by gravity and airflow. The interactions between the droplets will lead to adhesion and soldering. In the process of droplet cooling and solidification, whether the complete spheroidization can be carried out will determine the sphericity of powder. The spherification of metal droplets is the result of the interaction between viscosity and surface tension. When the shape time is longer, the sphericity and surface finish of the spherical metal powder are better.