Investigations on Mechanical Properties of Lattice Structures with Different Values of Relative Density Made from 316L by Selective Laser Melting (SLM)

Abstract

Nine variants of regular lattice structures with different relative densities have been designed and successfully manufactured. The produced structures have been subjected to geometrical quality control, and the manufacturability of the implemented selective laser melting SLM technique has been assessed. It was found that the dimensions of the produced lattice struts differ from those of the designed struts. These deviations depend on the direction of geometrical evaluation. Additionally, the microstructures and phase compositions of the obtained structures were characterized and compared with those of conventionally produced 316L stainless steel. The microstructure analysis and X-Ray Diffraction XRD patterns revealed a single austenite phase in the SLM samples. Both a certain broadening and a displacement of the austenite peaks were observed due to residual stresses and a crystallographic texture induced by the SLM process. Furthermore, the mechanical behavior of the lattice structure material has been defined. It was demonstrated that under both quasi-static and dynamic testing, lattice structures with high relative densities are stretch-dominated, whereas those with low relative densities are bending-dominated. Moreover, the linear relationship between the energy absorption and relative density under dynamic loading conditions has been defined

Influence of Geometric and Manufacturing Parameters on the Compressive Behavior of 3D Printed Polymer Lattice Structures

“…The statistical analysis confirms that cell size and strut thickness influence the plateau stress of lattice structures. This outcome is consistent with previous studies that explored the influence of cell size and strut diameter on the mechanical response of lattices [7,[28][29][30][31]. The strength and modulus of the lattices increased with the decrease in the unit cell size and/or increase in strut diameter, due to the associated denser structures [29].…”

“…The influence of diverse geometric parameters (unit cell type, cell size, cell orientation, strut thickness, strut cross-section, etc.) on the mechanical properties of lattice structures has been investigated by analytical, numerical, and experimental techniques [7,[26][27][28][29][30][31]. For instance, scaling law models have been used to model the relationship between strut diameter, cell size, and mechanical properties [22,28], and have been validated experimentally [7,[29][30][31].…”

A discretization method for predicting the equivalent elastic parameters of the graded lattice structure

“…With the deepening of the research, the configuration mode, 10,11 distribution characteristics, 12 equivalent elastic properties 13,14 of the cellular materials and related research methods are gradually studied. 15,16 In order to further explore the performance advantages of cellular materials, people's focus has been extended from uniform lattice structures to nonuniform lattice structures such as graded lattice and variable-density lattice, 17 and the performance of cellular materials has expanded from structural lightweight to multi-functional characteristics, such as vibration resistance, shock resistance, heat and heat transfer, sound absorption and noise reduction, and zero/ negative thermal expansion, ect. 18,19 Seharing et al 20 analyzed the design, mechanical behaviors, manufacturability, and application of the graded lattice structure manufactured via metallic additive manufacturing technology.…”

“…With the deepening of the research, the configuration mode, 10,11 distribution characteristics, 12 equivalent elastic properties 13,14 of the cellular materials and related research methods are gradually studied. 15,16…”