Metal lattice porous materials are advanced lightweight and multifunctional materials with complex periodic structure. Due to its excellent specific strength, sound absorption, noise reduction and metamaterials, they has attracted much attention in recent years. These characteristics make the metal lattice porous materials have a wide range of applications in the fields of medical implantation and aerospace. At the same time, the traditional preparation process can only manufacture lattice-like structures, and has many defects, making them difficult to produce complex and fine lattice structures, making the application of metal lattice porous materials encounter a bottleneck. In recent years, the rapid development of additive manufacturing (AM) technology has the characteristics of large design, manufacturing freedom and rapid manufacturing of any complex geometric parts. It is the forefront of metal lattice porous materials preparation technology to regulate and control multiple combinations of grids. However, the additive manufacturing of metal lattice porous materials have problems such as large residual stress, high surface roughness, and local stress concentration, which result in low compression brittleness and low fatigue strength. Therefore, in recent years, in addition to studying the effects of additive manufacturing process parameters on the performance of lattice structures, researchers have continued to try from the perspective of topology optimization and post-processing, and have achieved fruitful results. Combined with topology optimization design, it can make the stress distribution more uniform and better serve in different loading environments; the compressive strength and energy absorption of the gradient lattice structure are more than twice that of the uniform lattice structure; it can be reduced by heat treatment and chemical etching. The residual stress and surface roughness of the lattice structure greatly increase the fatigue strength of the lattice structure. By controlling the hierarchical porosity distribution of the unit cell structure and appropriate post-treatment, it is expected to achieve high porosity, high fatigue strength and high energy absorption at the same time. This article first states the advantages and forming criteria of additively manufactured metal lattice porous materials, and then introduces the influence of the unit cell shape, unit cell size, pillar diameter, volume porosity and other factors on the lattice structure dimensional accuracy and surface roughness. And summarized the influence of these factors on the yield strength, energy absorption rate and fatigue strength of the lattice structure. In addition, the effects of topology optimization and post-processing of the lattice structure on its performance are summarized. Finally, the obstacles of the metal lattice structure of additive manufacturing are introduced, and the future research trends are prospected. © 2021, Materials Review Magazine. All right reserved.
