Screening method of 3D printing powder

Abstract

The invention discloses a screening method of 3D printing powder, and the method comprises the steps of screening powder prepared by gas atomization by using an air classifier, and removing ultrafinepowder with the granularity of -15 [mu]m to obtain powder with the granularity of 15-250 [mu]m; carrying out ultrasonic screening on the powder with the granularity of 15-250 [mu]m by using a glove box to obtain printing powder with the granularity of 15-45 [mu]m; and packaging the printing powder with the granularity of 15-45 [mu]m. According to the invention, ultrafine powder and large-particle-size powder in the powder are removed in sequence by continuously screening the powder prepared by gas atomization; and the quantity of the ultrafine powder is effectively reduced by controlling the rotating speed and the air input of the wind wheel of the air classifier, the ultrasonic frequency and the screening time of an ultrasonic vibration screening machine, the humidity and the oxygen increasing amount of the printed powder are effectively reduced by controlling the parameters such as the water content and the oxygen content of the glove box, and the gas-filled packaging prevents the vacuum packaging from causing powder agglomeration and adhesion to influence the flowability of the powder..

Description

technical field [0001] The invention relates to the technical field of 3D printing, in particular to a screening method for 3D printing powder. Background technique [0002] 3D printing technology has the advantages of high precision, short cycle time, material saving, and the ability to prepare complex integrally formed parts. It has become the latest research focus at home and abroad. For metal laser 3D printing, metal powder is the material basis for rapid prototyping of printed parts. The shape, fluidity, oxygen content, bulk density, and particle size of metal powder directly determine the final performance of 3D printed parts. Metal laser 3D printing is divided into powder-spreading printing and powder-feeding printing. The current mainstream method is powder-spreading printing. Powder-spraying printing requires metal powder to have good fluidity. The better the fluidity of the powder, the more uniform the powder spreading Powder with good fluidity can not only improv...

AI Technical Summary

Problems solved by technology

[0003] The preparation of printing powder is generally prepared by gas atomization. The basic principle of gas atomization is to use high-speed airflow to scour and break liquid metal into small droplets and then solidify into powder. The powder prepared by this method generally has a normal distribution, and the particle size distribution range is 0~300μm, ultrafine powder with a particle size of -15μm will inevitably be produced during the atomization process, and the ultrafine powder will be adsorbed on the surface of other powders, affecting the fluidity of the powder. At the same time, the powder is transferring, screening, packaging, It is inevitable to be in contact with the air during the storage process. The moisture in the air will make the powder surface wet and affect the fluidity of the powder. Poor fluidity of the powder will affect the thickness and uniformity of the powder coating; at the same time, the oxygen in the air It will oxidize the powder surface and increase the oxygen content of the powder

The above problems will lead to incomplete powder sintering and low bonding strength during the printing process, and the performance of the resulting printed parts is not up to standard