Abstract
Additive manufacturing technology can process parts with complex shapes and has great application potential in the biomedical and aerospace industries. However, additively manufactured parts have a poor surface finish, high porosity, and large tensile residual stresses and thus have poor mechanical properties compared with traditional cast or forged parts. To address this issue, an innovative surface enhancement technology, namely electropulsing-assisted ultrasonic nanocrystal surface modification (EP-UNSM) technology, is proposed. A pulsed current is exerted on the sample to improve the metal plasticity during the UNSM processing, thereby further enhancing the strengthening effect. The results have demonstrated that EP-UNSM can further improve the surface integrity and surface hardness of the samples. In addition, compared with continuous current, pulsed current can more effectively improve the plasticity of Inconel 718, even though the effective current density and thus the thermal heating effect are the same. This enhancement effect is more significant at higher peak current density, proving the athermal effect of electroplasticity.
