Restoring Plasticity in Nickel-Based Superalloy Using High-Density Pulsed Electric Current

Abstract

This study explores the efficacy of high-density pulsed electric current (HDPEC) in healing plastic deformation damage in single-crystal Ni-based superalloys. Single-crystal specimens are prepared from directionally solidified nickel-based superalloy to assess the potential of electric current treatment in restoring plastic deformation capability. Experiments involving various current densities and pulse durations reveal that a pulsed electric current of 17 ms at 400 A mm−2 yields optimal results, enhancing fracture elongation from 7.8% to 12.3% without compromising strength. The study conducts a comprehensive analysis of microstructural changes induced by pulsed electric current, employing quasi-in-situ electron backscatter diffraction and transmission electron microscopy techniques. The results demonstrate that HDPEC disrupts the planar dislocation network, homogenizes dislocation distribution, and promotes dislocation entanglement. Consequently, microdefects in the alloy are eliminated, restoring the material's ductility. The findings suggest that this technology holds significant promise for repairing fatigued components and underscore the potential for further research in this domain.