Study on the residual stress of simple cubic lattice structure produced by selective laser melting

Abstract

Lattice structures become the focus for scholars to research due to its unique lightweight, high impact resistance and ideal noise reduction. Selective laser melting has become a very effective and convenient method for preparing lattice structures of excellent quality. However, it is imperative to acknowledge that rapid heating and cooling processes inherent to the method can generate excessive residual stresses within the lattice structures, thereby significantly compromising their mechanical properties. To address this issue, the present study seeks to elucidate the patterns and characteristics of distribution of residual stresses and deformations within simple cubic lattice structures, employing a combination of experimental techniques and finite element analysis. The fabrication of these simple cubic lattice structures is accomplished through selective laser melting. The investigation encompasses both two methods, involving X-ray measurements at discrete points on the structure, and finite element simulations to depict the overall stress distribution. The results show that the residual stress and deformation are more likely concentrated on the initial surface to be processed, and residual stress on the substrates is bigger than that on bars. Specifically, the biggest stress concentrates on the Z-bars, up to 1393 MPa. However, in terms of the overall state of stress distribution in the structure, the residual stress on the substrate is slightly higher than that on the lattice structure.