Potential and perspectives on additive manufacturing of high-entropy alloys for ballistic impact applications

While the design of complex shaped parts is enabled using additive manufacturing (AM) techniques, the need for tailoring microstructures catering to the requirements of specific applications must not be neglected. Considering the level of design complexity involved in the design of parts for ballistic applications, AM techniques may be envisaged to be employed in their design. On the other hand, there are innumerous reports, especially since the last decade, on a new class of metallic materials known as high-entropy alloys (HEAs) or multicomponent alloys, extensively investigated for their microstructure-property relation for a number of different applications. However, it may be noted that such studies are mainly limited to fundamental research and have not systematically focussed on correlating the findings of fundamental research with real-time applications. Therefore, considering that both AM and HEAs are relatively "new" and "booming" areas of research, the present book chapter provides a review on the development of AM HEAs towards designing components (e.g. armors) with high resistance to dynamic impact applications, in order to qualify themselves as alternatives and even superior to conventional materials (such as steels) for high-end ballistic applications. Additionally, this chapter will also focus on the challenges associated with employing AM HEAs for these applications and provide a roadmap for both fundamental and industrial research through strategies to design AM HEAs.