How is the 3D printing metal powder being made

       

According to the different preparation
process, the preparation methods of metal powder can be divided into reduction
method, electrolysis method, grinding method, atomization method and so on. At
present, argon atomization and plasma rotating electrode are commonly used in
China.

1.
Argon atomization

The powder by argon atomization is a method
of powder making by using the rapid flow of argon to impact the metal liquid,
breaking it into small particles, and then condensing it into solid powder.

2.
Plasma rotating electrode method

Plasma state is called the fourth state of substance.
The process of powder production by plasma rotary electrode atomization (PREP)
can be described as follows: metal or alloy are made into consumable
electrodes, and the end of consumable electrode melts into liquid film under
the action of coaxial plasma arc heating source. The liquid film is dumped into
droplets at high speed under the action of rotating centrifugal force. Molten
liquid drops and inert gas in atomization chamber can be described as follows:(The
friction of argon or helium) further breaks under the shear stress, and then
the droplets cool and solidify rapidly to spherical powder under the action of
surface tension.

The
metal powder produced by plasma rotating electrode method has the following
advantages:

The ball degree is high, the surface is
smooth, the fluidity is good, and the loose density is high. Therefore, the
powder spreading uniformity is good and the printing product is dense; the
powder particle size is small, the particle size distribution is narrow, the
oxygen content is low, the printing time is less / no spheroidization and
agglomeration phenomenon, the melting effect is good, the surface finish of the
product is high, and the consistency and uniformity of the printing can be
fully guaranteed; there is no hollow powder or satellite basically In the
process of printing, there will be no air gap, entrapment, precipitation
porosity, crack and other defects caused by hollow ball.