Cyclic Deformation Mechanisms in a 3D-Printed High-Entropy Alloy

The design flexibility afforded by additive manufacturing, commonly known as 3D printing, is broadening the industrial applications of high-entropy alloys (HEAs). The 3D-printed CrMnFeCoNi HEA (or Cantor alloy) exhibits a unique combination of strength and ductility, attributed to its multifaceted deformation mechanisms. While the deformation behavior of this alloy under monotonic loading has been extensively studied, its cyclic plasticity, which is crucial for fatigue performance, remains a relatively underexplored area. To address this gap, the current work investigates the deformation microstructure of a CrMnFeCoNi HEA fabricated using laser-beam powder bed fusion. Electron backscatter diffraction (EBSD) is employed to characterize the surface microstructural changes. The results reveal the simultaneous activation of multiple slip systems in the region near the fatigue crack, which induces grain rotation. Additionally, the activation of twinning-induced plasticity plays a significant role in accommodating the cyclic plastic strain.