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 strut orientation in relation to the specimen-building direction. 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 dependency between the value of energy absorption and relative density under dynamic loading conditions has been established.

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 ].…”

On the application of additive manufacturing methods for auxetic structures: a review

“…Structures made of H13 tool steel [86] were realized through this method. Similarly, SLM can also be used to manufacture commercial steel variants such as SS316L stainless steel with great accuracy to fabricate auxetic structures [87]. SLM has also been used to manufacture stable thin and thick-walled AlSi10Mg lattice structures [88].…”

Numerical Investigations and Benchmarking of the Physical and Elastic Properties of 316l Cubic Lattice Structures Fabricated by Selective Laser Melting

“…316L steel grade is also a notable research topic for the SLM production of lattice structures. For the current state-of-the-art, the types of lattice structures produced by SLM from 316L are gyroid [9], face-2-centered cubic (F2CC) [10], X-shaped [11], octet truss [12], (Z reinforced body-centered cubic) BCCZ [13], [14], cubic [15], octahedral [16], BCC [17], [18], [19] and gradient [20]. As can be seen through listed literature there are many studies on the SLM production of lattice structures from 316L, but there is a certain gap of a comprehensive benchmark between various lattice types and geometrical characteristics.…”