Centrifugal Atomization Preparation Of Spherical Aluminum Powder For 3D Printing And CFD Simulation

The nature of powder for 3D printing has an important impact on The properties of additive manufacturing Parts.The Particle size of The powder which is produced by The traditional aerosolization technology has poor uniformity and much holes,which seriously affects The quality of The additive manufacturing products.In this Paper,a high speed centrifugal atomization method was used to prepare spherical aluminum powder for 3D printing,The influence of centrifugal atomization parameters on The properties of spherical aluminum powder was studied,and The VOF model and K-ω SST turbulence model provided by CFD software fluent were used.The forming process of spherical powders and The role of atomization parameters in The process of atomization are simulated.The Paper has The main Theory guiding function and use value for The high quality 3D printing spherical aluminum powder production.Firstly,The spherical aluminum powder was prepared by high speed rotating plasma atomization,and The results showed that with The increase of rotational speed,The spherical degree of powder increased,The degree of adhesion increased,and The Particle size became smaller.With The increase of atmosphere pressure,The adhesion degree of powder decreased,The Particle size of powder was reduced and Then increased.With The increase of arc pressure,The spherical degree of powder increases.When The rotational speed is 6000 rpm and The atmosphere pressure is 0.02 MPa,The aluminum powder with high spherical degree,small Particle size,smooth surface and less satellite ball can be prepared.The microstructure of powder is mainly cell-like,and The roughness of powder surface is mainly related to The quantity of crystal grains on The surface.The Paper uses computational fluid dynamics software model to prove that The atomization process of fluid under high rotational speed centrifugal action is as follows:The molten aluminum fluid first splits The liquid ring of different radius at The bottom of The rotating disk,Then The liquid ring of centrifugal force and frictional force gradually distorts,cracks,forms droplets and leaves The rotating disk,The large droplets which have left The rotating disk will continue to deform,crack and form small droplets under The action of centrifugal force,and The droplets in The space are cooled to form solid spherical Particles.The increase of rotational speed can improve The deformation,cracking and The formation of liquid droplets,and The radius of The liquid ring becomes smaller with The increase of rotational speed.In The process of rotating atomization,The gas has The dual effect of accelerating atomization force and increasing liquid cooling speed,and The liquid ring radius decreases first and Then increases with The increase of ambient atmosphere pressure.The increase of liquid flow can reduce The viscous force of liquid,and The droplet size decreases with The increase of liquid flow.