Interferometry of Gas-Phase Flows during Selective Laser Melting

Pavel A Podrabinnik,Roman S Khmyrov,Alexander E Shtanko,Andrey D Korotkov,Andrey V Gusarov

doi:10.3390/app10010231

Pavel A Podrabinnik, Roman S Khmyrov + Show 3 more

Open Access

https://doi.org/10.3390/app10010231

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Abstract

Gas-phase flows occurring in a plume in a processing zone during selective laser melting (SLM) can significantly affect the quality of the process. To further enhance SLM performance, the characteristics of the flows should be considered. In this article, the vapor-gas jet emerging from the laser processing zone was studied. It was visualized by interferometry to evaluate flow velocity, geometry and changes in refractory index depending on laser power. The velocity and pressure fields of the vapor jet and the entrained ambient gas were estimated by mathematical modeling. It was shown that the increase of laser power led to higher jet velocity and greater change in its refractory index. The latter also was used to evaluate the content of metal vapor in the plume and its influence on the absorption of laser radiation.

Highlights

Developing additive technologies (AT) provide the ability to manufacture parts of complex shape directly from computer models, avoiding time-consuming operations of manufacturing special molds, tools and equipment settings
Previous works on the study of gas-phase flows in Selective laser melting (SLM) indicate several aspects that accompany their formation: changes in pressure, temperature and concentration of metal vapor [5,25,26,27,28]
A method for studying the vapor-gas jet that arises during SLM process based on interferometry with subsequent digital processing was applied

Summary

Introduction

Developing additive technologies (AT) provide the ability to manufacture parts of complex shape directly from computer models, avoiding time-consuming operations of manufacturing special molds, tools and equipment settings. It makes AT widely demanded due to their flexibility and the ability to quickly obtain final products. This dramatically changes the technology of product development in mechanical engineering, the technology of prosthetics in medicine and makes it possible to quickly prototype parts of complicated shape. Selective laser melting (SLM) is one of the key technologies due to its applicability to a wide range of structural and functional materials, including steel. In the laser spot area, the melting temperature is reached even for refractory materials

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