Influence of the particle size distribution on surface quality and mechanical properties in AM steel parts

Abstract

Abstract:A recent study confirmed that the particle size distribution of a metallic powder material has a major influence on the density of a part produced by SLM. Although it is possible to get high density values with different powder types, the processing parameters have to be adjusted accordingly, affecting the process productivity. However, the particle size distribution does not only affect the density but also the surface quality and the mechanical properties of the parts. Therefore, this study compares three different particle size distributions depending on the laser scan velocity and two layer thicknesses of 30μm and 45μm. By using an optimized powder material a low surface roughness can be obtained. A subsequent blasting process can further improve the surface roughness for all powder materials used in this study although this does not change the ranking of the powders with respect to the resulting surface quality.

On the Anisotropic Mechanical Properties of Selective Laser Melted Stainless Steel

“…In addition to the pure irradiation, the information of the raw metal powder, mainly its size and the distribution, is also of great importance and should not be neglected. Spierings, et al [13] pointed out the necessity of having both small and large powder particles: Fine particles are easily molten and favour a good relative density and surface quality; whereas bigger powder particles benefit the ductility. On this note, the mechanical properties, such as hardness and tensile strength, greatly correspond with the relative density, which is, without a doubt, the most utilized characteristic to evaluate the quality of fabricated components [10].…”

Surface Quality Research for Selective Laser Melting of Ti-6Al-4V Alloy

“…Selective Laser Melting (SLM) is an additive manufacturing method that uses a laser in an inert atmosphere to selectively melt layers of loose metal powder into a solid, building a part layer by layer from the bottom up [2,3]. Selective laser melting and electron beam melting typically utilize the entire melting mechanism that completely dissolved all particles of metal powder and generates a compact and stable solid body [4,5]. The powder material is subjected to a series of complicated chemical and physical phenomena such as oxidation, wetting, epitaxial solidification, and vaporization.…”

Mechanical properties and microstructure evolution of 17-4 PH stainless steel processed by laser-powered bed fusion.

“…Table 2.3 summarizes powder characteristics (shape and size distribution) for five types of steels from 25 sources and represents typical sintered densities (represented as % theoretical) obtained from the L-PBF process when different types of powder production routes and particle size distributions are used. [33][34][35][36][37]56] Gas-atomized 0 -60 99.5 ± 0.3…”

“…Among tool steels, H13 tool steel had the highest tensile strength value of 1850 ± 25 MPa when processed using L-PBF. [68][69][70][71][72][73][74][75] 520 ± 50 [72,73,[76][77][78][79][80] 550 ± 20 [37,[81][82][83][84][85][86][135][136][137] 17-4 PH stainless steel 1050 ± 40 [71,73,74,87,88] 1070 ± 40 [73,[77][78][79][89][90][91][92][93] 1080 ± 30 [32, 39, 41, 42, 94-103, 138, 139-141] 420 stainless steel 1700 ± 40 [71,73,[104][105][106][107][108][109] 1700 ± 30 [71, 73, 77-79, 105, 108, 110] 1600 ± 50 …”

“…were showed suitable compatibility with the L-PBF process since it was possible to achieve hardness similar to the wrought and MIM values. [28][29][30][31][32][33][34][35] 115 ± 50 [32,33,[36][37][38][39][40] 120 ± 20 [41][42][43][44][45][46][47] 17-4 PH stainless steel 360 ± 40 [71,73,74,87,88] 340 ± 40 [73,[77][78][79][89][90][91][92][93] 360 ± 30 [32,42,58,[94][95][96][97][98][99][100][101][102][103] 420 stainless steel 460 ± 40 [71,…”