Cracking control method for SLM (Selective Laser Melting) forming of strip-shaped or sheet-shaped structural member

Abstract

The invention relates to a cracking control method for SLM (Selective Laser Melting) forming of a strip-shaped or sheet-shaped structural member. The method comprises the following steps of: 1, designing the printing direction of the strip-shaped or sheet-shaped structural member, and designing an auxiliary support to meet the forming requirements except cracking; 2, designing multi-claw type supporting structures at the two ends of the strip-shaped or sheet-shaped structural member in the length direction by adopting three-dimensional cartographic software; 3, designing a through hole in at least one of a main claw and an auxiliary claw; 4, designing skirt steps below the strip-shaped or sheet-shaped structural member and the multi-claw type supporting structures; and 5, carrying out manufacturability detection on the structural member to be printed, and slicing, layering and printing after the manufacturability requirement is met. According to the cracking control method for SLM forming of the strip-shaped or sheet-shaped structural member provided by the invention, the characteristics of increasing the connecting area and relieving concentrated stress and stress release can be achieved through the multi-claw type supporting structures, cracking of the strip-shaped or sheet-shaped structural member in the selective laser melting forming process is well restrained, and deformation of the strip-shaped or sheet-shaped structural member is reduced.

Description

technical field [0001] The invention belongs to the technical field of additive manufacturing, in particular to a cracking control method for SLM forming of a strip or sheet structure. Background technique [0002] In recent years, the additive manufacturing technology has developed rapidly, gradually moving from the laboratory to the application. At present, it has been gradually applied in the fields of aerospace, medical treatment, and mold manufacturing. "Baby Bantam" rocket motor made of 3 parts. In 2017, GKN used 3D printing technology to manufacture a nozzle with a diameter of 2.5 meters for the Ariane 6 rocket, reducing about 1,000 parts to about 100 parts. There are also many successful cases of the application of additive manufacturing technology in our country. For example, the relay star of Chang’e 4 uses a variety of complex aluminum alloy components printed by 3D, and its self-weight is less than 50% of traditional products; the J-31 fighter jet uses nearly 10...

AI Technical Summary

Problems solved by technology

For the deformation problem, it can basically be solved by increasing the process margin, but how to solve the cracking problem of the strip and sheet structure in the selective laser melting process and improve the product qualification rate is a major pain point in the current industry

Replacing materials or improving the plasticity of materials can improve the forming of strip and sheet structures, but currently there are less than 20 mature materials available for selective laser melting, and it is difficult to find alternative materials that meet the requirements of strength, plasticity and temperature; However, the cycle of developing new materials is lengthy and costly; for the problem of cracking, optimizing the forming process, such as reducing heat input and layer thickness can also improve the cracking problem to a certain extent, but the improvement effect is not obvious. The input will lead to a decrease in density, and reducing the layer thickness will result in a decrease in efficiency

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