Microstructure and hardening effect of pure tungsten and ZrO2 strengthened tungsten under carbon ion irradiation at 700°C.

Microstructure evolution and hardening effect of pure tungsten and Wâ€"1.5%ZrO2 alloy under carbon ion irradiation are investigated by using transmission electron microscopy and nano-indentation. Carbon ion irradiation is performed at 700 °C with irradiation damages ranging from 0.25 dpa to 2.0 dpa. The results show that the irradiation defect clusters are mainly in the form of dislocation loop. The size and density of dislocation loops increase with irradiation damages intensifying. The Wâ€"1.5%ZrO2 alloy has a smaller dislocation loop size than that of pure tungsten. It is proposed that the phase boundaries have the ability to absorb and annihilate defects and the addition of ZrO2 phase improves the sink strength for irradiation defects. It is confirmed that the Wâ€"1.5%ZrO2 alloy shows a smaller change in hardness than the pure tungsten after being irradiated. From the above results, we conclude that the addition of ZrO2 into tungsten can significantly reduce the accumulation of irradiated defects and improve the irradiation resistance behaviors of the tungsten materials. [ABSTRACT FROM AUTHOR]