The issue of quality assurance of materials in additive manufacturing of metal products

Abstract

The article addresses the quality issues of additive manufactured products from the perspective of materials science. Additive manufacturing is multilayered step-by-step deposition of a material in micro-volumes following the trajectory controlled by a CNC program. Such heating sources as electric arc, laser, plasma and electron beam can be used to melt the metallic powder. This article investigates the structure and properties of titanium alloy Ti-6Al-4V ELI produced by selective laser melting (SLM). The samples were produced in pure argon environment in a system with a 3D printer EOS M290 (Electro Optical System GmbH, Germany) and then heat-treated in vacuum at 750...800 °C during 3 hours. It was revealed that the main structural defects reducing mechanical properties of material are pores and stress concentrators in the points of contact between titanium alloy particles and the newly built surface of the previous layer. The ways aimed to avoid the structural defects which reduce fracture toughness were suggested.