Laser additive manufacturing method applied to large-sized metal part

Abstract

The invention provides a laser additive manufacturing method applied to a large-sized metal part. The laser additive manufacturing method comprises the following steps: according to the configuration characteristics and load distribution characteristics of the integral structure of the part, dividing the part into a plurality of sub-blocks; according to the shape structure characteristics of all the sub-blocks, separately dividing the sub-blocks into a plurality of scanning areas: wed plate scanning areas, edge strip scanning areas, T-shaped block scanning areas and ear plate scanning areas, and then setting the scanning sequence according to the principle that priority is given to the farthest scanning area; adopting a short-edge reciprocating scanning mode in the scanning areas, guaranteeing the consistent widths of scanning paths in the scanning areas, and completing the manufacturing of all the sub-blocks; assembling, clamping and positioning the manufactured sub-blocks according to the position relation determined when the part is divided into the sub-blocks, guaranteeing that deformation allowance is left at the seam between two adjacent sub-blocks, and adopting a deformation mapping mode for positioning between two adjacent sub-blocks; and subjecting all the positioned sub-blocks to laser additive connection till all the sub-blocks are connected together to form a whole, thereby completing the manufacturing of the part.

Description

technical field [0001] The invention belongs to the technical field of laser additive manufacturing, in particular to a laser additive manufacturing method suitable for large metal parts. Background technique [0002] Laser Additive Manufacturing technology (Laser Additive Manufacturing, referred to as LAM, commonly known as 3D printing technology), uses alloy powder as raw material, melts the alloy powder in situ through high-power laser, and makes the alloy powder in the molten state solidify rapidly and gradually deposition to make solid parts. [0003] The principle of laser additive manufacturing technology is as follows: first, use computer 3D software to design a 3D model of the part, and then perform layered slice processing on the 3D model in the computer to discretize the 3D model into a series of 2D layers, and finally use laser Scan and add alloy powder layer by layer, and finally convert the 3D model part into a solid part. [0004] From the point of view of c...

AI Technical Summary

Problems solved by technology

[0005] However, due to the characteristics of rapid heating and rapid cooling in the laser additive manufacturing process, especially the part substrate and the deposited layer will experience long-term periodic intense heating and cooling of the laser beam during the deposition process, and the moving molten pool will be in the Rapid solidification and shrinkage under the constraints of the bottom of the pool, accompanied by short-term non-equilibrium cyclic solid-state phase transitions, which will generate large and complex thermal stress, tissue stress and mechanical constraints inside the part, accompanied by strong unsteady interaction Action and stress concentration phenomenon, the direct consequence is deformation and cracking of parts

[0006] For large metal parts, after long-term reciprocating scanning of the high-energy laser beam, there will also be a serious heat accumulation effect inside the part, which will aggravate the deformation and cracking of the part

Therefore, the quality of laser additive manufacturing of large metal parts has been difficult to control, which seriously limits the application of large metal parts in the field of laser additive manufacturing

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