Investigation of interfacial strength in nacre-mimicking tungsten heavy alloys for nuclear fusion applications

Tungsten heavy alloys have been proposed as plasma facing material components in nuclear fusion reactors and require experimental investigation in their confirmation. For this purpose, a 90W-7Ni-3Fe alloy has been selected and microstructurally manipulated to present a multiphase brick-and-mortar structure of W-phase 'bricks' surrounded by a ductile 'mortar'. This work draws inspiration from nature to artificially imitate the extraordinary combination of strength and stiffness exhibited by mollusks and produce a nacre-mimicking metal matrix composite capable of withstanding the extremely hostile environment of the reactor interior and maintaining structural integrity. The underlying mechanisms behind this integrity have been probed through high-resolution structural and chemical characterization techniques and have revealed chemically diffuse phase boundaries exhibiting unexpected lattice coherency. These features have been attributed to an increase in the energy required for interfacial decohesion in these systems and the simultaneous expression of high strength and toughness in tungsten heavy alloys.

Automated summary

Tungsten heavy alloys are being studied as plasma facing material components in nuclear fusion reactors. In this study, a 90W-7Ni-3Fe alloy was used to create a multiphase brick-and-mortar structure, inspired by the strength and stiffness of mollusks. The high-resolution structural and chemical characterization techniques revealed chemically diffuse phase boundaries with unexpected lattice coherency, contributing to the high strength and toughness of tungsten heavy alloys.