Microstructure and mechanical properties of specimens produced using the wire-arc additive manufacturing process

The additive manufacturing technique is becoming popular and promising in recent years. Some steel ER70S-6 specimens were produced by wire arc additive manufacturing. Before the tensile tests, 3D X-ray computed tomography was applied to detect the presence of internal defects due to the production process. Static tensile tests were performed in order to analyze the influence of the different directions (deposition and layer stacking directions) on the mechanical properties. The digital image correlation technique was applied during the tests for detecting the displacement and strain fields, while infrared thermography was applied for detecting the temperature field of the specimen surface. After the mechanical tests, scanning electron microscopy was employed to analyze the fracture surfaces of the specimens. The results showed the presence of small defects that did not affect the mechanical properties of the specimens and no significant anisotropy was detected in the two directions (deposition and layer stacking directions).