A Laser Additive Manufacturing Method for Large Metal Parts

Abstract

A laser additive manufacturing method suitable for large metal parts, the steps are: according to the configuration characteristics and load distribution characteristics of the overall structure of the part, divide the part into several sub-blocks; The block is divided into several scanning areas, which are divided into web type, edge type, T-type block type and ear plate type scanning area, and then the scanning order is sorted according to the principle of the farthest area priority; in the scanning area The short-side reciprocating scanning method is adopted inside, and the scanning path width in the scanning area is guaranteed to be consistent, and the manufacture of all sub-blocks is completed; the manufactured sub-blocks are assembled and clamped according to the positional relationship determined during the block division. And ensure that there is a deformation margin at the joints of adjacent sub-blocks, and the deformation mapping method is used to position adjacent sub-blocks; each sub-block that has been positioned is connected by laser additive material until all sub-blocks are connected together and Form a whole, and the parts are manufactured.

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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