Deformation Behavior of 3D‐Printed High‐Entropy Alloys: A Critical Review

Abstract

The 3D‐printing of high‐entropy alloys (HEAs) is capable of enhancing the design and manufacturing flexibilities for novel materials. Owing to the rapid solidification, the 3D‐printed HEAs exhibit markedly different microstructures than their conventionally‐manufactured equivalents, leading to peculiar mechanical properties. Many additively manufactured HEAs also break down the strength‐ductility trade‐off dilemma. Novel dynamics regarding the simultaneous and sequential nature of deformation mechanisms are emerging through recent intensive research on these materials. Herein, the deformation behavior of 3D‐printed HEAs is reviewed and explained on the basis of the latest advances in this area. A comprehensive picture regarding the role of cellular dislocation networks, twinning‐induced plasticity, and transformation‐induced plasticity in the monotonic and cyclic deformation of 3D‐printed HEAs is presented. Special emphasis is placed on fatigue characteristics due to the enormous interest in this burgeoning area. The effect of postfabrication thermomechanical processing on plasticity is discussed along with the microstructural evolution in the 3D‐printed HEAs. Several innovative developments that carry latent potential for further research are also deliberated in this review. Finally, the present understanding of the deformation behavior of 3D‐printed HEAs is summarized while gauging the future directions.