Protective gas preheating method and device for 3D printing

Abstract

The invention discloses a protective gas preheating method and a device for 3D printing. The device comprises a protective cover, and a vacuum preheating cavity arranged in the protective cover; two gas heating channels with the same structure are arranged in the vacuum preheating cavity; gas enters the gas heating channels from an intake port for heating to enter the vacuum preheating cavity, and enters a molding chamber from an exhaust port; and each gas heating channel is divided into two sub channels for gradient heating. The structure increases paths of inert gas entering the vacuum preheating cavity, and uses a gradient heating method for enabling the heated inert gas to be more stable, so that the temperature difference of a laser scanning area and the gas in the molding chamber is reduced; and meanwhile, the secondarily heated inert gas can continuously preheat metal powder on inner surface layers of a molding cylinder and a powder cylinder, so that the temperature difference in the layers and between the layers is largely reduced, the thermal stress is reduced, and the residual stress and deformation in the SLM molding process are reduced.

Description

technical field [0001] The invention relates to the technical field of laser selective melting metal 3D printing (SLM), in particular to a protective gas preheating method and device for 3D printing. Background technique [0002] 3D printing technology, also known as additive manufacturing technology, has changed the traditional manufacturing mode. Laser selective melting (SLM) technology is a kind of metal 3D printing. Its forming principle is to discretize the designed three-dimensional model into layer-by-layer contour information, control the laser beam to scan the metal powder to form a melting channel, and the melting channels overlap to form layers. , stacked layer by layer to form a three-dimensional metal part. Compared with traditional manufacturing technology, one of the outstanding advantages of SLM technology is that it can almost directly form functional parts with any complex structure and complete metallurgical bonding, and the density can reach nearly 100%....

AI Technical Summary

Problems solved by technology

Excessive thermal stress during processing can even cause the support to be broken, and the processed layer will be severely warped, which will not only affect the shape accuracy and dimensional accuracy of the part, but also damage the flexible plaster

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