Influence of Ti content on synthesis and characteristics of W–Ti ODS alloy

• A low Ti content in W alloys has a uniform microstructure and higher hardness.
• Milling and sintering processes are important in formation of Ti–O particles.
• The material behaviour is strongly affected by Ti–O particles.
• A complex Ti2Y2O7 structure combined with TiO2 was obtained.

Tungsten–titanium alloys are considered as promising materials for the future fusion devices, in particular for the divertor and other first wall components. The microstructure and the mechanical properties of the material are dependent on the amount of Ti present in the alloy. In this study, W–Ti–Y2O3 alloys with varied Ti contents between 1 wt.% and 10 wt.% fabricated by mechanical alloying were investigated. The effect of Ti on the phase formation and mechanical properties of W–Ti–Y2O3 alloys has been examined. The results suggest that the alloys containing low Ti content exhibit homogeneous microstructure with a uniform distribution of fine titanium oxide particles and tungsten carbides, leading to a significant increase in hardness and elastic modulus of alloys. In addition, high-energy ball milling can facilitate a solid-state reaction between Y2O3 particles and the tungsten–titanium matrix and the subsequent sintering processing promotes the formation of stable nano Ti2Y2O7 oxide particles, which greatly increase the mechanical properties at elevated temperature and enhance irradiation resistance.