Effect of Process Parameters on Residual Stresses, Distortions, and Porosity in Selective Laser Melting of Maraging Steel 300

Abstract

Selective laser melting (SLM) is one of the most well-known additive manufacturing methods available for the fabrication of functional parts from metal powders. Although SLM is now an established metal additive manufacturing technique, its widespread application in industry is still hindered by inherent phenomena, one of which is high residual stresses. Some of the effects of residual stresses – such as warping and thermal stress-related cracking – cannot be corrected by post processing. Therefore, establishing input process parameter combinations that result in the least residual stress magnitudes and related distortions and/or cracking is critical. This paper presents the influence of laser power, scanning speed, and layer thickness on residual stresses, distortions and achievable density for maraging steel 300 steel parts in order to establish the most optimum input parameter combinations. An analysis of the interdependence between process outcomes shows that high residual stress magnitudes lead to high dimensional distortions in the finished parts, whilst porous parts suffer relatively lower residual stresses and associated distortions.

A modified volumetric energy density–based approach for porosity assessment in additive manufacturing process design

“…In order to consolidate the use of the proposed modified VED as design parameter, it was chosen to apply it to experimental data taken from literature about SLM of Maraging steel 300 [44]. Results are shown in terms of porosity versus VED (Eq.…”

“…It is clearly shown how the use of the proposed modified VED is able to discriminate a narrow range of energy density (as in previous case) in which sound specimens, characterized by the lowest porosity values, can be obtained. On the opposite, the use of standard VED formulation is unable to explain or account for the differences in the observed process outcomes, as also outlined by the authors of the paper which experimental data are taken from [44].…”

A New Approach in the Design of Microstructured Ultralight Components to Achieve Maximum Functional Performance

“…The effect of process parameters on residual stresses, distortions, and porosity in Selective Laser Melting (SLM) was studied [ 2 ] for Maraging Steel 300, and in [ 3 ] for Inconel 718 (co-authors previous work). Moreover, some studies also worked on the effect of the ti6al4v alloy track trajectories on mechanical properties in direct metal deposition [ 4 ], the effect of microstructure, crystallographic texture and morphological texture on the mechanical properties of 3D printed 316L stainless steel [ 5 ] and the effect of scanning strategy on grain structure and crystallographic texture of Inconel 718 processed by selective laser melting [ 6 ].…”

Corrosion Behaviors of Selective Laser Melted Aluminum Alloys: A Review

“…Growing attention has been paid to 3D printing due to the significant advantages it offers in manufacturing products with complex structures without extra machining processes [1][2][3]. As 3D printing can produce components with complex geometries, which are needed in many industries, it is widely used to produce various metallic parts, made from different metals, including aluminum alloys [4], titanium alloys [5,6], steels [7][8][9], nickel alloys [10,11] and shape memory alloys, [10,12]. Mehrpouya et al summarized in their review that 3D printing exhibits enormous market potential in industry 4.0 due to its significant advantages, such as time and materials saving and high design freedom [13].…”

“…Selective laser melting (SLM) is one of the most promising 3D printing methods mainly used to manufacture metal products by selectively melting the layers composed of metal powders [14][15][16]. SLM process is widely used to produce aluminum parts [4], titanium parts [5,6], biomedical parts [17], steels parts [7][8][9] and so on [18].…”