ABSTRACT
Investigations on fracture and fatigue behaviour of high entropy alloys and the allied groups, like multi-element complex concentrated alloys, have started almost a decade after the emergence of this alloy concept in 2004, in order to assess the potential of these alloys for structural applications. Understanding achieved in this direction is thus still in an embryonic state. The information generated and the knowledge achieved over the last few years on fracture and fatigue behavior of high entropy alloys and the allied group of alloys are compiled in this chapter, with a brief background of the concepts developed so far for these disciplines over a century. Interestingly, structural evolution of high entropy alloys encompasses single or multiphase constituents with the common crystal structures (fcc, bcc, and hcp) and the methodologies adopted to evaluate their fracture and fatigue resistance incorporate all the standard practices. The well-known deformation mechanisms which are operative for the improvement of fracture and fatigue response in advanced structural materials also govern these properties in high entropy alloys, with minor variations.
