Studying the influence of initial powder characteristics on the properties of final parts manufactured by the selective laser melting technology

Abstract

Selective laser melting (SLM) is an additive manufacturing process that enables direct manufacturing of 3D complex shape parts and internal architecture from powder materials. The SLM technology is characterised by high temperature gradients and solidification rates that have a significant effect on the microstructures and properties of final parts. The present paper aims at understanding the influence of the initial properties of various martensitic stainless steel powders on the final microstructures and mechanical properties of parts manufactured using the same optimised SLM process parameter settings. The results obtained show that for applied optimum process parameters, the thermal effects are the same for all martensitic powders used. Besides, the final microstructures and properties are different. The results clearly show the effect of the initial complex chemical composition of the martensitic precipitation hardening powder on the microstructures of final parts, and consequently, on their properties.

Electrical conductivity and porosity in stainless steel 316L scaffolds for electrochemical devices fabricated using selective laser sintering

“…Laser re-melting (outer contour and inner contour parameters) were used in this study so that sample shell strength could be improved, better surface quality achieved, while at the same time retaining a high internal porosity. This result agrees with the findings of other studies, in which laser re-melting can improve the density and enhance the surface roughness of printed parts [35,40,41]. From these findings, the high porosity parts, which were generally printed using an energy density less than 2.00 J/mm 2 , might not print well if their shells were too weak.…”

Microstructures, properties, and applications of laser sintered 17‐4PH stainless steel

“…Laser‐powder bed fusion (L‐PBF), alternately known as selective laser melting (SLM), is a powder‐based process that uses focused laser energy to melt the metallic powders into solid parts. In the L‐PBF process, the laser‐powder interactions are largely affected by processing conditions such as laser power, scan speed, hatch spacing, and layer thickness . In general, the above processing conditions along with powder characteristics such as size, shape, and purity significantly determine the density, microstructures, and properties obtained from L‐PBF parts .…”

“…In the L-PBF process, the laser-powder interactions are largely affected by processing conditions such as laser power, scan speed, hatch spacing, and layer thickness. [1][2][3][4][5][6][7][8][9][10] In general, the above processing conditions along with powder characteristics such as size, shape, and purity significantly determine the density, microstructures, and properties obtained from L-PBF parts. [6][7][8][11][12][13][14][15][16][17] In our former work, 18,19 a comprehensive study was performed to understand the role powder characteristics such as powder type, shape, and size along with L-PBF processing conditions on densification, mechanical properties, and microstructure of 17-4 PH stainless steel L-PBF parts.…”

Prediction of porosity in metal-based additive manufacturing using spatial Gaussian process models

“…One example is the work by Averyanova et al [4] who use a fractional factorial approach to assess the impact of process and material parameters on the dimensional stability and surface roughness of a single layer 17-4 PH. The effect of the optimized process parameters on the microstructure of the final part is subsequently studied in [52]. Spierings et al [53] employ fullfactorial experimental design examine the effect of energy density on the density and elasticity of 17-4 PH specimens.…”