Control device and method for heat stress in powder bed type electron beam additive manufacturing

Abstract

The invention discloses a control device for heat stress in powder bed type electron beam additive manufacturing. The control device comprises a transparent glass window located on a vacuum chamber and arranged in the shooting direction of a camera; the camera shoots images of the interior of the vacuum chamber through the glass window, and the shot images comprise a powder layer and the temperature distribution information of the powder layer; a rotating shaft which penetrates through the vacuum chamber in a sealing mode and can rotate is arranged on one side of the glass window and is fixedly connected to a baffle located in the vacuum chamber, and the baffle is driven by the rotating shaft to switch between the position of shielding the glass window and the position of avoiding the glass window. The invention further provides a control method for controlling the heat stress in additive manufacturing. According to the invention, the camera shoots the images of the interior of the vacuum chamber through the glass window, the shot images comprise the powder layer and the temperature distribution information of the powder layer, and therefore the heat stress in additive manufacturing can be controlled better; by arranging the baffle, the transparency of the glass window can be effectively maintained, and the replacement frequency of the glass window is lowered.

Description

technical field [0001] The invention relates to the technical field, in particular to a thermal stress control device and method in powder bed electron beam additive manufacturing. Background technique [0002] Additive manufacturing (3D printing) is a manufacturing technique that builds three-dimensional objects by successively fusing more than one thin layer of material. Powder bed electron beam additive manufacturing is a kind of additive manufacturing technology route. Its basic process steps are as follows: the powder supply and paving system spreads the powder material into a thin layer on the working platform, and the electron beam with high energy density A section of the three-dimensional object is scanned on the powder layer; after that, the working platform is lowered by a distance of the thickness of the powder layer, a new layer of powder is laid on the working platform, and the next section of the three-dimensional object is scanned by rays; the above steps are...

AI Technical Summary

Problems solved by technology

However, in this method, the baffle is opened each time for a long time, which is far longer than the exposure time required by the camera to capture an image.

Therefore, when the baffle is opened, the glass observation window is exposed to metal vapor. After repeated opening many times, the glass observation window will still be contaminated by evaporation, resulting in an excessively high frequency of replacement

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