Influence of surface treatment on mechanical properties and structure of 3D-printed alloys

In a modern world, additive manufacturing of metal products has reached significant volumes and variety of applied alloys. 3D-printing technologies make it possible to obtain parts with reduced mass, increased reliability, single products, experimental parts and elements designs with complex geometry and configuration. Disadvantages of metal parts additive manufacturing include anisotropy of chemical composition and properties, non-equilibrium structural-phase state, structural micro- and macrodefects and some other features, that require post-processing of as-printed products. Most often, heat treatment and its combination with microforging or intensive surface plastic deformation are used for this purpose. The manuscript provides an analytical review of the advantages of using ultrasonic technologies to support 3D-printing and post-processing of additively manufactured products. Special attention is paid to ultrasonic impact treatment (UIT). The equipment for providing UIT is compact, energy-saving and easy to use. It is noted, that this technology makes it possible to effectively reduce surface defects of printed parts, increase its hardness and fatigue strength. At the same time, nanostructuring and changes in the structural and phase state of the modified layers are also occurred. It is also noted, that UIT may provide surface strengthening to a depth of ~500 μm, saturating it with alloying elements and compounds, and for conventionally produced parts, like as–cast, deformed and powder sintered – it is significantly more effective than most other similar methods. The prospects of using ultrasonic technologies to improve quality and level of operational and mechanical characteristics of additively manufactured metal parts, including the needs of aircraft construction, are outlined.