Tiny tweaks to tungsten alloys could transform jet engine durability
Researchers using computer modeling have discovered that adding osmium to tungsten alloys makes them significantly harder and more stable than similar osmium-free variants—but only within a precise composition window. The finding could help aerospace and power-generation industries design materials that withstand extreme temperatures without cracking, potentially extending engine life and reducing maintenance costs.
Originaltitel: Mechanical stability and fracture behavior of the WOs sigma phase: Effects of composition and lattice-site occupancy
<p>Precipitates of the topologically close-packed (TCP) phases can significantly impact a material’s mechanical and fracture properties. This theoretical study uses ab initio modeling to investigate the σ phase of WOs, focusing on composition-dependent mechanical and fracture-related properties. We find the effect of Os on WOs σ to be stronger than that of Re in WRe σ phase, with the WOs phase exhibiting peak hardness at the ideal concentration. This difference is attributed to variations in d-orbital filling, causing Os to favor low-coordination sites more strongly than Re. While ductility may improve at high Os contents, brittle fracture of the σ phase is still predicted. For Os concentrations above 78 at.%, the σ phase becomes mechanically unstable. These results indicate that subtle changes in d-orbital filling between Os and Re significantly affect the stability and mechanical properties of the σ phase and may apply to similar TCP phases.</p>