A method to reduce residual stress and unsteadiness in additive manufacturing by optimizing substrates

Abstract

The invention discloses a method for reducing additive manufacturing residual stress and the unsteady state by optimizing a substrate. In the method, the shape of the substrate is directly optimized,the substrate only keeps the shape of the contact face of a target part, it is guaranteed that enough supporting force can be given to an additive manufacturing part on the aspect of thickness, and mechanical constraints of the substrate to a forming part in the part manufacturing process are reduced; and the substrate is designed to be of a hollowed structure, the maximum temperature gradient inthe additive manufacturing process is adjusted and controlled, and finally the residual stress of the additive manufacturing part and the unsteady state stage in the forming process are reduced. The method can be used for metal additive manufacturing processes, including laser stereoscopic forming, selective laser melting, electronic beam fuse wire deposition and the like, with various high-energybeams (lasers, electronic beams, plasma beams, arcs) as hot sources.

Description

【Technical field】 [0001] The invention belongs to the field of high-energy beam additive manufacturing, and in particular relates to a method for reducing residual stress and unsteady state of additive manufacturing by optimizing a substrate. 【Background technique】 [0002] High-energy beam additive manufacturing is an advanced industrial manufacturing technology that manufactures high-performance complex metal parts through the principle of discrete accumulation. This technology uses computer CAD software for three-dimensional modeling, layered slicing and path planning, and the computer transmits data to additive manufacturing. In the control system of the equipment, the metal powder or wire is deposited layer by layer on the substrate by using a high-energy beam (laser, electron beam, plasma and arc) heat source, and finally the desired target part is obtained. However, the additive manufacturing process is a non-uniform, fast, multi-scale thermal-structure-stress couplin...

AI Technical Summary

Problems solved by technology

[0004] Previous studies on welding and high-energy beam additive manufacturing have shown that methods such as preheating the substrate before forming, adjusting processing parameters, and imposing mechanical constraints can be used to reduce residual stress and deformation, but preheating the substrate will increase energy consumption and adjust Process parameters will narrow the process window and imposing mechanical constraints will increase tooling complexity

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