Tungsten Boride and Future Nuclear Fusion Applications

tungsten boride (WB) is one of the most stable and hard materials used in fusion applications. It combines the well-known advantages of tungsten with boron's thermo-mechanical properties, and is therefore an attractive alloy for future nuclear fusion technology.

Tungsten is the most abundant element on earth and has been used in a variety of applications for its strong and lightweight properties. But it also exhibits thermo-mechanical deficiency at high temperatures and thereby suffers from limitations in mechanical performance in extreme irradiation environments such as in a nuclear fusion reactor. To improve its mechanical properties tungsten is commonly alloyed with elements/materials such as boron, carbon, molybdenum, and nickel, aimed at minimizing the irradiation damage on it.

In order to understand the physico-chemical properties of tungsten boride and its potential for future nuclear fusion applications, several experimental studies on the material have been conducted over the years. This research has led to a better understanding of boron's interaction with tungsten and other elements, and has also provided insights into boron-rich materials with rich and complex crystal structures.

The boron atoms of the hP20-WB4 structure are connected to the tungsten atoms by short bonds. This leads to a void-like three-dimensional network of boron atoms with tungsten atoms sitting in the voids (Fig. S1). The space group P63/mmc has been established by Romans and Krug2, and the material is believed to have a lattice constant of 5.2 A for a and 6.34 A for c.