Device and method for rolling laser stereo formed part layer by layer

Abstract

The invention discloses a device and method for rolling a laser stereo formed part layer by layer. The device comprises a numerical control system, a working table, a base plate, laser powder coaxialnozzles located above the base plate and a rolling device. By adopting the scheme that the numerical control system controls the rolling device to roll a metal deposition layer, the rolling frequencyand rolling deformation of a rolled area can be freely adjusted, the problems of high residual stress and severe warping deformation produced due to the high temperature gradient in the laser stereo forming process of the part are solved, and meanwhile by means of the rolling force of rollers, grains are refined, dislocation is increased, cracks are reduced, and part compactness is improved. The size precision and mechanical property of the laser stereo formed part can be improved, the metal part with the high quality is formed, and follow-up machining treatment for the part is reduced.

Description

technical field [0001] The invention belongs to the technical field of rapid prototyping, and relates to an additive manufacturing device and method, in particular to a device and method for layer-by-layer rolling laser three-dimensional forming parts. Background technique [0002] Different from traditional "subtractive" and "equal material" manufacturing, additive manufacturing can directly manufacture parts by adding materials based on the data model. Compared with traditional manufacturing methods, additive manufacturing technology can manufacture difficult-to-machine complex parts with high efficiency and low cost, and has broad application prospects in aerospace, automotive, and biomedical fields. According to the different molding methods, laser additive manufacturing can be divided into powder-spreading laser selective melting and powder-feeding laser three-dimensional molding. Laser stereoforming is suitable for low-cost, high-speed rapid prototyping of large-sized...

AI Technical Summary

Problems solved by technology

Because the laser three-dimensional forming technology uses a high-power laser to locally heat the substrate, resulting in large thermal stress, manufacturing defects and obvious warping deformation, which will adversely affect the mechanical properties and dimensional accuracy of the part, and even cause the part to be formed. Failure; and with the increase of the number of printing layers, the heat dissipation conditions of the molten pool become worse, the cooling rate becomes lower, and the grain size of the deposited layer becomes larger, resulting in a further reduction in the mechanical properties of the component

Patent CN201620873214.4 uses a roller frame to compact and spread powder on the self-leveling substrate to increase the density to reduce the warpage of the part. By compacting the powder before melting, it is still impossible to avoid the laser heating and the increase in the number of printing layers. The problem of part deformation caused by

CN201010248416.7 Metal wire is melted by laser to form molten droplets. The molten droplets accumulate and cool on the workbench, and form thin slices with the movement of the worktable. Each thin slice is deposited layer by layer to form three-dimensional metal parts. This invention uses metal molten droplet Replace the powder spreading method to improve the structure of the part, but the coarse columnar grain structure of the final part cannot be avoided, and there is still a large residual thermal stress inside the part, resulting in poor comprehensive mechanical properties of the molded part

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