Mechanical Properties of AISI 316L Lattice Structures via Laser Powder Bed Fusion as a Function of Unit Cell Features

Abstract

The growth of additive manufacturing processes has enabled the production of complex and smart structures. These fabrication techniques have led research efforts to focus on the application of cellular materials, which are known for their thermal and mechanical benefits. Herein, we studied the mechanical behavior of stainless-steel (AISI 316L) lattice structures both experimentally and computationally. The lattice architectures were body-centered cubic, hexagonal vertex centroid, and tetrahedron in two cell sizes and at two different rotation angles. A preliminary computational study assessed the deformation behavior of porous cylindrical samples under compression. After the simulation results, selected samples were manufactured via laser powder bed fusion. The results showed the effects of the pore architecture, unit cell size, and orientation on the reduction in the mechanical properties. The relative densities between 23% and 69% showed a decrease in the bulk material stiffness up to 93%. Furthermore, the different rotation angles resulted in a similar porosity level but different stiffnesses. The simulation analysis and experimental results indicate that the variation in the strut position with respect to the force affected the deformation mechanism. The tetrahedron unit cell showed the smallest variation in the elastic modulus and off-axis displacements due to the cell orientation. This study collected computational and experimental data for tuning the mechanical properties of lattice structures by changing the geometry, size, and orientation of the unit cell.

A Review on Vibration Characteristics of Additively Manufactured Metal Alloys

“…For example, Ti6Al4V, [ 24,56 ] stainless steel 316, [ 57 ] and other biocompatible materials with novel LSs can be fabricated with electron beam melting to develop implants for the biomedical industry. [ 58–60 ] Similarly, functionally graded materials (FGM) are widely used for various applications, and various studies investigate their distinctive vibrational response. [ 55,61–64 ]…”

“…For example, Ti6Al4V, [24,56] stainless steel 316, [57] and other biocompatible materials with novel LSs can be fabricated with electron beam melting to develop implants for the biomedical industry. [58][59][60] Similarly, functionally graded materials (FGM) are widely used for various applications, and various studies investigate their distinctive vibrational response. [55,[61][62][63][64] The dynamic behavior of materials and structures is often assessed by measuring the system reaction to a known input or excitation-typically mechanical vibration or shock.…”

Nanostructuring of Additively Manufactured 316L Stainless Steel Using High-Pressure Torsion Technique: An X-ray Line Profile Analysis Study

“…AM can be used in a wide range of industries, including aerospace [4][5][6], medical [7][8][9] and automotive [10,11] industries, due to its ability to create complex components and parts [12][13][14][15][16]. Furthermore, AM provides additional benefits, such as reduced material waste [1,12], the quick production of prototypes [14,15], a reduced cost for small production runs [12,17], environmental friendliness [18], and supply chain flexibility [19,20].…”

Design and Study of Fractal-Inspired Metamaterials with Equal Density Made from a Strong and Tough Thermoplastic

“…Cell orientation can also affect mechanical properties, by shifting the deformation to stretching-dominant from bending. [31] In addition to the traditional geometric and structural changes, there are also different ways to create lattice structures with more favorable properties. Tan et al [32] created a structure whose energy absorption can be interpreted not only in the elastic but also in the plastic zone, under repeated loading.…”

“…Cell orientation can also affect mechanical properties, by shifting the deformation to stretching-dominant from bending. [ 31 ]…”