How is metal powder made for 3D printing?

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 the two most advanced pulverizing processes in China.

Two preparation methods of 3d metal printing powder

1. Argon atomization method

Argon atomization powder making method is to use the fast flowing argon flow to impact the metal liquid, break it into fine particles, and then condense into solid powder.

2. Plasma rotating electrode method

The plasma state is called the fourth state of matter, and the powder preparation process by plasma rotating electrode atomization (PREP method) can be simply described as:  The metal or alloy is made into a consumable electrode, and the consumable electrode extreme part is melted to form a liquid film under the action of coaxial plasma arc heating source. The liquid film is thrown out at high speed under the action of rotating centrifugal force to form droplets, and the molten droplets friction with the inert gas (argon or helium) in the atomization chamber, and further broken under the action of shear stress.  Then the droplets are cooled and solidified into spherical powder under the action of surface tension.

Advantages of 3d metal printing powder production methods

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

High sphericity, smooth surface, good fluidity, loose density, so good powder uniformity, high density printing products;  

Small particle size, narrow particle size distribution, low oxygen content, less/no spherification and agglomeration during printing, good melting effect, high surface finish, and the consistency and uniformity of printing can be fully guaranteed;  

There is basically no hollow powder, satellite powder, there is no air gap, involvement and precipitation pores, cracks and other defects brought by hollow balls in the printing process.