2020 №10 (02) DOI of Article
2020 №10 (04)

The Paton Welding Journal 2020 #10
The Paton Welding Journal, 2020, #10, 13-18 pages

Influence of technological parameters of slm-process on porosity of metal products

S.V. Adjamskyi1, G.A. Kononenko2 and R.V. Podolskyi3

1Oles Honchar Dnipro National University 72 Gagarin Prosp., 49000, Dnipro, Ukraine. E-mail:
2LLC «Additive Laser Technology of Ukraine» 144 Rybin’ska Str., 49000 Dnipro, Ukraine. E-mail:
3Z.I. Nekrasov Institute of Iron and Steel of the NAS of Ukraine 1 Academician Starodubov Sq., 49050, Dnipro, Ukraine. E-mail:
4National Metallurgical Academy of Ukraine 4 Gagarin Prosp., 49000, Dnipro, Ukraine. E-mail:

Selective laser melting is one of the modern methods of manufacturing parts and assemblies of complex geometry, which are difficult or impossible to reproduce in the conditions of traditional manufacturing. The problem of this manufacturing is that a product quality depends on many factors, which can be divided into such main groups as equipment, material, process, part and finishing. The influence of the specific energy density of scanning the heat-temperature Inconel 718 alloy in the 3D printer Alfa-150 (ALT Ukraine) of the Ukrainian production was investigated. The influence of SLM-technology parameters on the quality of final products is shown and the analysis of the influence of technology factors on the quality of finished products is performed. As a result of metallographic examinations, it was found that the distance between the passes of the laser, at which the estimated overlap of a single track is 25 %, the conditions of deep penetration are created and at the root of the track as a result of collapsing holes (so-called keyhole), large elongated pores are formed. At the estimated overlap of a single track of 17 %, a small number of tiny rounded pores is formed. At the calculated overlap of 0‒8 %, a structure with a minimum number of pores is formed. When the distance between the passes of the laser exceeds the width of a single track at a given combination of power and laser scanning speed, the cases of partial fusion of adjacent tracks are observed, pores with sharp edges are formed, which are stress concentrators — the most dangerous in terms of a product reliability. Thus, a rational overlap of tracks during selective laser melting was established, which ranges from 0 to 8 % of the width of a single track at specific process parameters. 21 Ref., 2 Tables, 4 Figures.
Keywords: selective laser melting, technological factors, quality system, Inconel 718, specific energy density

Received 27.08.2020


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