Effect of Gas Flow on Samples Produced by Selective Laser Melting

BACKGROUND: Selective laser melting (SLM) is a technology for manufacturing metal parts by melting particles of metal powder compositions using laser radiation. SLM provides excellent mechanical properties of manufactured parts and large discretion of design. The paper studies the effect of laser power on the spattering of molten powder. The study analyzed the causes, appearance, and composition of spatter and methods to prevent it. The SLM is performed in shielding inert gas; thus, it has been shown that the gas flow is a decisive factor as it removes condensate and prevents oxidation of the material during melting. The solidified spatter has an average size of approximately 162 µm, which is significantly larger than the initial powder size of 32 µm. AIM: To analyze the spatter of stainless steel powder during processing and the effect of gas flow on sample quality, especially its porosity. RESULTS: The study showed that gas flow rate significantly affects the uniformity of the properties of manufactured products. The properties of the manufactured parts varied based on the location of the samples on the platform. The quality of the manufactured parts was higher when placed in areas with high gas flow rate and lower when placed in areas with low gas flow rate. CONCLUSION: The study may be used to predict and test the quality of parts manufactured using the SLM.