Powder spreading apparatus for selective laser melting

Abstract

The invention discloses a powder spreading apparatus for selective laser melting. The apparatus comprises a funnel-type powder spreading bin used for holding powder to be spread and an adjusting device used for adjusting at least pressure of powder located at the powder outlet of the funnel-type powder spreading bin. According to the invention, the powder spreading bin with a funnel-type structure is employed and arranged along a vertical direction together with a processing platform; compared with the prior art, the powder spreading apparatus provided by the invention has a simple and compact structure, is free of idle stroke during round-trip powder spreading and can save driving energy needed in movement of the powder spreading apparatus, reduce energy consumption in powder spreading and improve powder spreading efficiency; powder at the bottom of the funnel-type powder spreading bin is used as a spreading powder source and has great pressure due to extrusion, so powder spreading compactness can be improved, thereby further improving part forming quality; the powder spreading bin can be also applied in research of powder fluidity and can effectively measure influence of a variety of factors on compactness of spread powder.

Description

technical field [0001] The invention relates to the technical field of metal powder laser melting forming, in particular to a selective laser melting powder spreading device. Background technique [0002] Metal powder laser melting forming system, also known as 3D printer, has attracted widespread attention because of its ability to form complex metal parts that can be used directly, and is predicted to be one of the key technologies that may trigger the "third industrial revolution". Powder spreading is an important part of selective laser melting. Using powder spreading to ensure the levelness and uniformity of the powder layer is a commonly used solution for metal powder laser melting forming systems. The powder spreading effect affects the compactness of the powder, and then It directly affects the molding quality of the parts. During the powder spreading process, the compactness of the powder is related to factors such as the flow of the powder and the pressure it recei...

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Problems solved by technology

Powder spreading is an important part of selective laser melting. Using powder spreading to ensure the levelness and uniformity of the powder layer is a commonly used solution for metal powder laser melting forming systems. The powder spreading effect affects the compactness of the powder, and then It directly affects the molding quality of the parts. During the powder spreading process, the compactness of the powder is related to factors such as the flow of the powder and the pressure it receives. The powder spreading device in the prior art generally includes a powder supply bin, a processing bin, a recovery bin and Powder spreading scraper, in which the bottom of the processing chamber is the processing platform, through the rise of the bottom of the powder supply chamber, the lowering of the processing platform and the horizontal movement of the scraper, the powder supply and powder spreading are realized, and the excess powder is scraped on the processing plane to eliminate excess powder. The powder is scraped into the recovery bin. The disadvantages are: the powder supply bin, the processing bin and the recovery bin are arranged along the same horizontal plane, the overall structure space is large, the movement path of the powder spreading scraper is long, and it takes a long time for the scraper to complete a powder spreading. Moving back and forth produces an empty stroke, resulting in high energy consumption and low efficiency of powder spreading. At the same time, the metal powder in the powder supply bin is in a natural accumulation state, and the top layer of powder in the powder supply bin is always used as the source of powder spreading. This part of the metal powder The pressure is small, and the powder density is poor, which affects the molding quality of parts

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