Unveiling the deformation mechanisms of BCC-superalloys

Body centered cubic (bcc)-superalloys – exploiting a two-phase microstructure composed of bcc matrix strengthened by coherent ordered precipitates – are emerging as a promising class of materials for high-temperature applications. Such alloys offer significant advantages especially in iron- and refractory-based systems, due to high melting points and superior mechanical strength. However, they often face critical challenges including limited ductility and toughness, phase instability or environmental vulnerability. Developing these alloys requires an integrated approach, from design to property assessment, and an in-depth understanding of deformation and strengthening mechanisms operating in the main phases across different scales.

This viewpoint article addresses the reported deformation mechanisms in bcc-superalloys with a particular focus on precipitation strengthening and dislocation interactions, and it proposes future research directions. Key aspects such as the transition between mechanisms, the role of the antiphase boundary energy, and the effect of chemical complexity especially in advanced refractory alloys remain open questions.