Study of the Effect of Selective Laser Melting Parameters on the Structure and Physico-Mechanical Properties of a Blank Made of Stainless Chromium-Nickel Steel

Abstract

Currently, there are a number of additive technologies that are used in various industries (laser fusion of powder materials, electron beam melting, etc.). The formation of metal structures and products by methods of additive technologies occurs by adding a new layer of material and its further melting (sintering), ensuring the adhesion of each subsequent layer with the previous one in accordance with digital model data. The advantages of using and developing additive technologies include the possibility of using a wide range of materials, obtaining finished products with complex geometries, restoring and repairing damaged structures, as well as the possibility of applying protective and anticorrosive coatings. Metal powder materials with specified physical and mechanical properties are of crucial importance in additive manufacturing. The main requirements for such powders include requirements for their shape and size. The preferred particle shape is spherical, as it provides a more compact installation in a given volume and the necessary fluidity of the material, which is due to the low resistance in the supply systems of powder materials in 3D printers. The aim of the work is to study the influence of the parameters of the SLM printing process on the structure and mechanical properties of products made of 12Cr18Ni10Ti alloy. Samples obtained by selective laser melting were subjected to pycnometric and metallographic analysis. Based on the obtained microstructure images, a digital porosity analysis of the work piece under study was performed in the Thixomet Pro software package. The microhardness and acoustic characteristics were also measured over the entire section of the work piece under study. It was revealed that with an increase in the distance from the substrate (0...112 mm) in the transverse and longitudinal sections, the tendency remains to decrease the density values and increase the volume fraction of pores. It is shown that the acoustic parameter Dc can be used to control changes in the physical and mechanical properties of stainless chromium-nickel steel blanks obtained by selective laser melting.