A rival to superalloys at high temperatures

Although conventional alloys are based mainly on one element, recent design efforts have focused on multiprincipal element alloys (MPEAs) that contain substantial quantities of several elements. Success with this approach requires a robust understanding of the mechanistic origin of MPEA properties. On page 95 of this issue, Wang et al. (1) report the deformation behavior in a promising body-centered cubic (bcc) MPEA with good room-temperature plasticity and high strength at the temperatures at which conventional alloys would soften. They observed multiplanar, multicharacter dislocation slip that was not expected in bcc systems. This property is attributed to variations in the glide resistance along the core of dislocations, created by the atomic-scale fluctuations in composition that are characteristic of MPEAs. This mechanism explains the plasticity and could be used to guide the design of new MPEA candidates for high-temperature applications in aerospace and power generation.