Recent progresses on designing and manufacturing of bulk refractory alloys with high performances based on controlling interfaces

Refractory alloys such as tungsten and molybdenum based alloys with high strength, thermal/electrical conductivity, low coefficient of thermal expansion and excellent creep resistances are highly desirable for applications in nuclear facilities, critical components in aerospace and defense components. However, the serious embrittlement limits the engineering usability of some refractory alloys. A lot of research results indicate that the performances of refractory alloys are closely related to the physical/chemical status, such as the interface dimension, interface type, interface composition of their grain boundaries (GBs), phase boundaries (PBs) and other interface features. This paper reviewed the recent progress of simulations and experiments on interface design strategies that achieve high performance refractory alloys. These strategies include GB interface purifying/strengthening, PB interface strengthening and PB/GB synergistic strengthening. Great details are provided on the design/fabrication strategy such as GB interface controlling, PB interface controlling and synergistic control of multi-scaled interfaces. The corresponding performances such as the mechanical property, thermal conductivity, thermal load resistance, thermal stability, irradiation resistance, and oxidation resistance are reviewed in the aspect to the effect of interfaces. In addition, the relationships between these interfaces and material properties are discussed. Finally, future developments and potential new research directions for refractory alloys are proposed. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.