RT Journal Article SR Electronic A1 Kučerová, Ludmila A1 Zetková, Ivana T1 Metallography of 3D Printed 1.2709 Tool Steel JF Manufacturing Technology Journal YR 2016 VO 16 IS 1 SP 140 OP 144 DO 10.21062/ujep/x.2016/a/1213-2489/MT/16/1/140 UL https://journalmt.com/artkey/mft-201601-0029.php AB 3D printing is a new and advanced technology of material processing, which belongs to additive manufacturing process. Products with complex geometries can be produced quickly with high precision from powder materials on the base of a CAD-model. Layers of powder particles are successively molten by laser beam. There are several metallographic issues connected with 3D printed microstructures. Laser beam processing is usually accompanied with high heating and cooling rates and therefore also with high thermal gradients. This is the reason why nonequilibrium phases and structural components can occur in the final microstructure. The microstructure could be also finer in comparison with the one produced by standard manufacturing methods. Porosity of the final microstructure is also an important factor, as it might deteriorate mechanical properties of the product. Thorough metallographic analysis of 3D printed materials is therefore necessary to ensure high quality of final components.