Multiple laser composite scanning process

Abstract

The invention discloses a multiple laser composite scanning process. According to the multiple laser composite scanning process, two total laser generators of a first laser and a second laser are adopted to perform laser melting on metal powder, when melting in performed, firstly scanning preheating is performed on a metal powder area by the first laser adopting a first power, then scanning melting is performed on the metal powder area by the second laser adopting a second power, finally scanning modification is performed on the metal powder area by the first laser or the second laser adoptinga third power, the first power is less than the third power, and the third power is less than the second power. By means of the multiple laser composite scanning process, a large number of cracks andpores can be reduced, each layer surface of a workpiece is made to be sintered sufficiently, the workpiece molding quality is good, and the fatigue life is significantly prolonged.

Description

technical field [0001] The invention relates to the technical field of selective laser sintering, in particular to a multi-laser composite scanning process. Background technique [0002] Laser sintering is a layered manufacturing technology. The premise of this technology is that the three-dimensional data of the object is available, and then the three-dimensional description is converted into a set of slices. Each slice describes the cross-section of the part with a certain height. Laser sintering passes These slices are accumulated layer by layer to obtain the required object. In each layer, the energy of the laser is used for powder melting. With the help of a scanning device, the laser energy is printed on the powder layer, which produces a solidification. This layer then becomes part of the finished object, and the next layer continues to be processed on top of the first layer until the entire processing process is completed. [0003] The traditional laser scanning met...

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Problems solved by technology

[0003] The traditional laser scanning method directly uses a high-power laser to sinter the metal powder. Due to the direct scanning on the metal powder, the scanning temperature rises too fast, so that the gas in the powder gap has no time to escape. As the scanning temperature increases, the metal powder melts and dies. Solidification molding, the gas in it expands after being heated, forming pores on the molding surface, which affects the quality of the workpiece, and when using high-power laser to scan directly, the temperature difference between the scanned area and the unscanned area is large, resulting in the scanned area and the unscanned area after the powder is scanned and solidified. Cracks are easy to occur between areas, which will reduce the fatigue life of the workpiece and affect the quality of the workpiece

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